WO2012031459A1 - 离岸高桩码头长分段结构 - Google Patents

离岸高桩码头长分段结构 Download PDF

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Publication number
WO2012031459A1
WO2012031459A1 PCT/CN2011/001521 CN2011001521W WO2012031459A1 WO 2012031459 A1 WO2012031459 A1 WO 2012031459A1 CN 2011001521 W CN2011001521 W CN 2011001521W WO 2012031459 A1 WO2012031459 A1 WO 2012031459A1
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pile
longitudinal
force
piles
temperature difference
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PCT/CN2011/001521
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English (en)
French (fr)
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陈明关
程泽坤
陈奉琦
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中交第三航务工程勘察设计院有限公司
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Publication of WO2012031459A1 publication Critical patent/WO2012031459A1/zh

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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D27/00—Foundations as substructures
    • E02D27/10—Deep foundations
    • E02D27/12—Pile foundations
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02B—HYDRAULIC ENGINEERING
    • E02B3/00—Engineering works in connection with control or use of streams, rivers, coasts, or other marine sites; Sealings or joints for engineering works in general
    • E02B3/04—Structures or apparatus for, or methods of, protecting banks, coasts, or harbours
    • E02B3/06—Moles; Piers; Quays; Quay walls; Groynes; Breakwaters ; Wave dissipating walls; Quay equipment

Definitions

  • the invention relates to the field of port engineering, and particularly relates to a high pile pier structure. Background technique
  • the pile foundation can adopt various structural forms such as square pile, large pipe pile, steel pipe pile, steel plate pile, lattice steel plate pile and composite pile.
  • the conditions for port construction have also developed from the harsh environment along the Yangtze River, coastal water depth and wind and waves to the harsh environment of offshore and deep water waves. According to the development trend of port engineering structure, China has carried out research on deepwater port construction technology since the 1980s.
  • the structure of high-pile wharf has been diversified. No matter the size of the wharf, especially the deep-water wharf in the outer sea, the structure of the high-pile wharf has been the most
  • the universal application can find examples of successful application of high-pile wharfs from a variety of complex geological conditions, from deep soft soil foundation to shallow overburden rock foundation.
  • the design theory and standard system of the high-pile wharf structure are also becoming more and more mature, and have reached the international advanced level, and are gradually becoming more complete.
  • the horizontal force distribution coefficient of the frame in the regular segment length is large, and the concrete pile (including large pipe pile, PHC pile, etc., the same below) is allowed in deep water or wave area.
  • the slope is small, so it is often impossible to use concrete piles to resist the horizontal force of the pier and to be forced to use steel pipe piles, thereby greatly increasing the construction cost and maintenance cost of the terminal.
  • the control of the segment length of the structure has two purposes: one is to eliminate the influence of differential settlement on the structure; the other is to eliminate the influence of the temperature difference and other stretching deformation on the structure; usually the segmented joint is the combined seam of the settlement joint and the expansion joint, and the high pile As for the wharf, due to the low height of the longitudinal beam of the superstructure and the prefabricated installation, the longitudinal stiffness is relatively small and the plasticity of the structure is also good. Therefore, the structure has a strong ability to adapt to vertical differential settlement. In the case of longitudinal geological changes, the structure itself can generally adapt to the differential settlement of longitudinally uneven and slowly varying, and usually only requires settlement joints at large load differences, large geological changes or structural faults.
  • the segment length of the high-pile wharf is usually controlled by the longitudinal expansion and deformation.
  • the length of the wharf is mainly limited to control the longitudinal expansion and longitudinal internal forces generated by the concrete shrinkage and meteorological temperature difference, and avoid the pile foundation. And the structure is damaged or affects normal use.
  • the segment length specified by the specification only simplifies the adaptability of the wharf structure. That is, the influence of temperature difference deformation and concrete shrinkage deformation on the structure can be ignored within the length of the segment.
  • the disadvantages are:
  • Some berths may not need to be segmented if they make full use of the segment length potential, but they must be segmented with a simplified segment length control value, which increases the expansion joint and the handling of the loading and unloading process across the expansion joint.
  • the pile height of the pile is large, and the longitudinal adaptability of the structure to concrete shrinkage and temperature difference deformation is much better than that of the traditional bank slope.
  • the length of the section should be allowed to increase as appropriate.
  • the length of the expansion joint section is much larger than the existing section length of the high-pile wharf. It is feasible to use the offshore water depth pier much longer than the traditional section length.
  • the dock has a large ability to resist horizontal horizontal forces, high rigidity and good integrity
  • the horizontal force shared by the piles is reduced, which is beneficial to the use of concrete piles instead of steel pipe piles.
  • the long section structure can generally be made of concrete piles. When all the concrete piles are not enough to resist horizontal forces, they can only be divided into two sections. The steel piles are replaced by steel pipe piles near the end, and the proportion of steel pipe piles used as a whole is still low;
  • the optimized pile foundation layout and structure setting scheme can be proposed for the long segment structure.
  • a new high pile wharf structure can be proposed to achieve further Technological innovation and the purpose of reducing costs.
  • the invention adopts further optimization techniques for the long segment structure as follows:
  • the longitudinal pile displacement from the temperature difference is 25m.
  • the fork piles are arranged at a small lateral angle to reduce the axial force of the longitudinal pile.
  • the distance between the first span of the long section and the first span can be smaller than the span of the inner span to reduce the design of the longitudinal beam, beam and pile to control the internal force and further reduce the cost.
  • Setting the post-concrete span of concrete can eliminate the influence of most concrete shrinkage and meteorological temperature difference on the structure, and can also reduce the differential settlement caused by the self-weight of the structure.
  • the long segment structure has a segment length of not less than 120 m, and the engineering condition is as high as 200 m or more, which is much larger than the segment length of the conventional high pile wharf.
  • the length of the section is based on the pile diameter of the specific wharf project, the length of the mud, the foundation condition, the connection of the pile top, the strength and rigidity of the pile body, the overall arrangement of the pile foundation, the shrinkage rate of the concrete after the longitudinal beam is installed, the construction and installation conditions, and the annual meteorological temperature difference.
  • the horizontal stiffness of the platform, the spacing of the racks and the horizontal stiffness of the studs are determined.
  • the long segment structure, the distance piles 25m away from the longitudinal displacement zero line of the temperature difference (such as zone B in Fig. 1) are arranged at a small lateral angle (Fig. 1 pile 3), and the angle should be arranged according to the pile foundation.
  • the piling deviation is determined by calculation.
  • Piling deviation should be considered: the top level deviation of the pile top, the azimuth deviation, the pitch angle deviation, the left and right swing angle deviation, etc., under the premise of ensuring that piles are not to be hit, the lateral angle of the pile should be minimized, and the angle between the piles should be minimized. Generally it can take 10 ⁇ 18°.
  • the following measures can be taken to further reduce the lateral angle of the fork piles: 1 Change the adjacent straight piles (such as pile 4 in Figure 1) that may hit the pile to a slope of not more than 20 : 1 reverse longitudinal oblique pile; 2 the top of the inclined pile and the adjacent straight pile top of the pile may be arranged with an offset of about 10cm from the axis of the frame (as shown in Figure 1 , the top of the pile is 10cm to the right, 4 piles) Top left 10cm).
  • the fork piles with several rows of the two edges can be replaced with the steel pipe piles with larger inclination (such as the F-section 5 of Figure 1).
  • the size and arrangement area of the pile is determined by calculation.
  • the long segment structure, the fork pile within 25m of the longitudinal displacement zero line of the temperature difference (such as the A area of Fig. 1) is arranged along the longitudinal direction (such as the pile 2 in Fig. 1), and if necessary, a part of the bearing capacity Straight piles with surplus are also arranged as longitudinally stressed piles.
  • the longitudinal angle of the longitudinally loaded pile is generally less than 45°.
  • the concrete pile can be used.
  • the inclination can be less than the concrete fork pile located 25m away from the longitudinal displacement zero line.
  • the minimum number of piles and the inclination of the longitudinally supported fork pile are divided by the pier.
  • the longitudinal horizontal force and seismic requirements of the segment are determined.
  • the long segment structure, the pile top hinge form can adopt different connection structures in different sections: the pile in the middle section is less than the pile top moment, and the pile top can be hinged by a conventional method;
  • the bending moment may be greater than the pile strength in the segmented edge region of the pile, and the pile top joint may adopt the hinge structure of the pile top bending moment proposed in the present specification.
  • the segmented two edges of the first spanning frame spacing (Fig. 1 spacing d) is smaller than the inner span spacing (Fig. 1 spacing c), to reduce the design of the longitudinal beams, beams and piles to control the internal forces, according to the edge of the shelf
  • the control internal force of the foundation pile, the longitudinal beam and the beam is close to the requirement of the internal force control of the intermediate frame, and the first span frame spacing is determined.
  • a longitudinal spanning pile should be removed every 40 to 60 meters before the longitudinal beam construction to completely release the longitudinal clamping pile force, and then the rear span is set to reduce the longitudinal section of the long section. Internal forces generated by concrete expansion and contraction.
  • the track connection at the dock expansion joint can adopt the track connection structure proposed in the present specification.
  • the invention successfully solves the technical problem of the application of the long segment structure of the wharf, and the long segment structure is suitable for the deep-water offshore high-pile wharf with uniform geological longitudinal direction and friction piles.
  • FIG. 1 is a schematic view showing the arrangement of a long section wharf pile foundation structure according to the present invention
  • FIG. 2a is a schematic view showing the elevation of the hinged pile of the pile top bending moment according to the present invention
  • FIG. 2b is a schematic plan view of the hinged pile for reducing the bending moment of the pile top according to the present invention
  • 2c is a perspective view of the inclined connection of the hinged pile for reducing the bending moment of the pile top according to the present invention
  • FIG. 3 is a schematic view showing the installation of a long segment wharf temperature seam track according to the present invention.
  • FIG. 4 is a top plan view of a long joint wharf plane joint joint according to the present invention.
  • Figure 5 is a front elevational view of the long joint wharf plane joint joint of the present invention.
  • Figure 6 is a plan view of the main section of the long section wharf according to the present invention.
  • Figure 7 is a left side view of the main section of the long section wharf according to the present invention.
  • Figure 8 is a front elevational view of the main section of the long section wharf according to the present invention.
  • Figure 9 is a schematic view of a long segment wharf connecting piece according to the present invention.
  • Figure 10 is a left side view of the long section wharf attached track of the present invention.
  • Figure 11 is a front elevational view of the long section wharf attached track of the present invention.
  • Figure 12 is a schematic view of a long section pier pressure plate according to the present invention.
  • Figure 13 is a schematic view of a long section pier bottom plate and a vertical plate according to the present invention.
  • Figure 14 is a plan view showing the installation of the expansion joint structure according to the present invention.
  • Figure 15 is a schematic view showing the assembly of the expansion joint structure of the present invention.
  • Figure 16 is a schematic view of a steel plate on an expansion joint structure according to the present invention.
  • Figure 17 shows the average temperature of January in China's coastal areas
  • Figure 18 shows the average temperature of July in China's coastal areas
  • Figure 19 is a temperature diagram for calculating the rectangular section of reinforced concrete, concrete and stone masonry
  • Figure 20 is a cross-sectional view of the dock
  • Figure 21 is a schematic cross-sectional view of the beam
  • Figure 22 is a schematic cross-sectional view of the longitudinal beam
  • Figure 23 is a schematic cross-sectional view of the track beam
  • Figure 24 is a calculation diagram of the width of the top plate of the middle plate slope
  • Figure 25 is a simplified diagram of the calculation of anchored steel bars and shear plates
  • Figure 26 is a diagram showing the post-casting across the two sides to strengthen the overall pile and the post-dumping longitudinal pile.
  • Figure 27 is a schematic view of the back pouring across the longitudinal plane. detailed description
  • the invention solves the following key technologies of the long segment structure of the pile pier
  • the offshore deep-water long-segment structure has obvious differences compared with the conventional structure, and has its own characteristics in terms of pile foundation arrangement, pile top connection, frame arrangement, construction technology, technical requirements and calculation methods.
  • the long segmented structure is an innovative structural type that requires addressing the following key technical issues:
  • the longitudinal displacement of the pile top near the edge of the segment is affected by concrete shrinkage and meteorological temperature changes.
  • longitudinally stressed piles are placed near the ends to enhance longitudinal resistance.
  • the inclined pile will generate a large temperature difference internal force, and how to arrange the pile foundation can not generate large temperature difference and increase pile strength, but also meet the horizontal and horizontal horizontal resistance requirements of the dock, and can exert the overall optimal effect of the pile foundation. It is a problem that needs to be solved.
  • the form of the pile top is mainly used to improve the horizontal resistance of the pier and enhance the horizontal stiffness.
  • the internal force generated by the contraction of concrete and the change of meteorological temperature by the newly-connected pile foundation is also large; It is difficult to make the pile top just after the wind and waves are large, and the articulated mode is to allow the connection point to rotate. It can adapt to the requirements of the construction in the wind and wave environment.
  • the length of the foundation mud is relatively large, and the fork pile is generally arranged, and the effect of increasing the horizontal resistance of the pile top is reduced. Therefore, it is necessary to study whether it is more reasonable to use the pile top hinge to increase the length of the section and reduce the horizontal force of the pile, so as to compensate the improvement of the horizontal resistance and rigidity of the pile top.
  • the pile top is buried in the pile cap or beam 5 ⁇ 10cm.
  • This hinge treatment method is convenient to construct, but it is the connection method between the hinge and the rigid joint.
  • the connection method In the segmented structure, there is no problem in using this connection in the middle part of the segment (as in the traditional 70m range), but in the segmented two edge regions, the bending moment of the pile top is greater than the strength of the pile when the calculation is just connected.
  • the foundation piles may still cause cracking of the pile top by traditional hinge method. It is necessary to study the innovative technology of pile top jointing, so that the pile top corner movement activity is large, the transmission bending moment is small, and it can adapt to the pile top of the long section pier. Hinging requirements.
  • the long-segment structure expansion joint has a large amount of expansion and contraction, and it is necessary to study the structure of the transition joint between the orbital machinery and other flow machines.
  • the long section pier Under the action of concrete shrinkage and meteorological temperature difference, the long section pier will produce large longitudinal expansion and displacement and longitudinal internal force. Since the section length of the high pile pier is usually controlled by longitudinal expansion and deformation, the concrete shrinkage and meteorological temperature difference are determined. The design value is an important parameter for designing the control segment length.
  • Offshore high-pile wharfs generally adopt integral assembly forms.
  • the factors that cause longitudinal deformation are: residual shrinkage deformation of concrete prefabricated longitudinal beams and prefabricated panels after installation, deformation caused by shrinkage of cast-in-place panels, creep of prestressed members, and annual weather Temperature deformation, etc.
  • 0 ⁇ is the average prestress of concrete, which is the elastic modulus of concrete, which has the same meaning as above, and can be taken as 0.35.
  • the concrete structure for integral casting is equivalent to a temperature reduction of 20 °C ;
  • the reinforced concrete structure for integral casting is equivalent to a temperature reduction of 15 °C;
  • the fabricated reinforced concrete structure is equivalent to a temperature reduction of 5 to 10 °C.
  • the composite panel is mostly used.
  • the concrete cast-in-place panel has a large shrinkage, but the cast-in-situ panel is constrained by the prefabricated longitudinal beam and the prefabricated panel. Since the concrete compressive strength is much higher than the tensile strength, For example, C30# concrete tensile standard value is 2.00MPa, compression standard value is 20.00MPa, and elastic modulus is 30000MPa.
  • C30# concrete tensile standard value is 2.00MPa
  • compression standard value is 20.00MPa
  • elastic modulus is 30000MPa.
  • the residual shrinkage deformation and prestressed creep deformation of concrete after installation of prefabricated components can be considered according to the equivalent cooling temperature of 12.4 °C. Considering the current design experience and actual measurement data of port engineering, the variation deviation can be appropriately increased. The influence, but should not exceed the equivalent reduction temperature of 15 °C for the reinforced concrete structure according to the whole pouring.
  • the lower limit of the equivalent cooling range is 5 °C and the upper limit is 15 °C.
  • the design value of meteorological temperature difference of concrete structure should consider the highest and lowest monthly average temperature of the year and the thickness and thermal conductivity of the beam.
  • the average monthly temperature in winter and summer varies across China.
  • the temperature difference in the north is large and the temperature difference in the south is small.
  • the meteorological temperature difference can be obtained from the monthly average temperature difference between the lowest month and the highest month.
  • the average temperatures in January and July along the coast are shown in Figures 17 and 18.
  • the average monthly temperature in Guangzhou is at least 13 °C and the highest is 28 °C; the average monthly temperature in Shanghai is the lowest 3'C and the highest is 28 ⁇ ; the average monthly temperature in Tianjin is -5 °C and the highest is 26 °C.
  • the thickness of both the high-pile wharf deck and the longitudinal beam is mostly less than 0.8m. It is 3°C when the temperature is the lowest in 3'C in Shanghai and 30°C when the temperature is 28°C.
  • the following is a unified calculation of the temperature difference between the concrete shrinkage equivalent cooling and the annual meteorological temperature difference.
  • the equivalent temperature drop of concrete shrinkage can be taken as 5 ⁇ 15 °C, according to unfavorable conditions; the calculated value of meteorological temperature change in Shanghai can be as low as 3 °C and up to 30 °C. .
  • the calculated temperature difference between concrete shrinkage and meteorological temperature changes can be considered in combination with adverse conditions.
  • the current high-pile terminal specification does not specify how the longitudinal force and temperature difference affect the internal force of the structure.
  • the following two methods are usually used: 1 It is assumed that the longitudinal force is assumed by a specially set longitudinal fork pile; 2 Calculated by spatial calculation method The effect of longitudinal force.
  • the method of assuming that the longitudinal force is carried by a specially arranged longitudinal fork pile is simple, but does not take into account the effect of a large number of straight piles and transverse fork piles in resisting the longitudinal horizontal force, and does not consider the adjacent sections after the expansion joint is closed by force.
  • the joint work, this method is too conservative, and is generally suitable for the calculation of the vertical horizontal resistance of the terminal by simple measures.
  • the longitudinal calculation is mainly to determine the internal force of the pile, and the internal force of the upper structure does not have to be calculated very accurately, as long as it is calculated according to the internal force of the pile.
  • the simplified method of longitudinal calculation of the structure requires consideration of factors such as the connection of the pile top, the height of the pile, the flexibility of the pile, and the arrangement of the pile foundation.
  • the embedded point method has higher internal force accuracy under load, and the internal force error calculated under displacement is larger. It is not suitable to use the embedded point method for calculating the pile bending moment generated by the displacement. For the calculation of the load and displacement The resulting internal force of the pile is obtained by the m method with relatively high precision.
  • the pile top connection of the pile is divided into two types: rigid joint and hinge. Considering that the corner stiffness of the just-joined pile is generally much smaller than the corner stiffness of the longitudinal beam system, it can be assumed that the pile top does not produce a corner under the concrete contraction, the meteorological temperature difference expansion and the longitudinal load. Since the pile top moment value calculated at the top of the pile top angle is the largest, this assumption is also safe for calculating the internal force of the pile top.
  • the axial stiffness of the pile under tension and compression is constant. That is to say, the fork pile basically does not produce vertical displacement under the action of horizontal force, ignoring the vertical displacement of the pile top joint under the action of temperature difference and horizontal force. This assumption makes the axial pressure calculated by the pile generally too large, and the axial tension is sometimes small. Generally, it is generally safe. The calculation accuracy can meet the design requirements of the long segment structure under the temperature difference and horizontal force.
  • the internal force of the straight pile is analyzed first, and then the internal force of the inclined pile is further analyzed based on the straight pile results.
  • the axial force of the pile can be calculated as follows:
  • the lateral stiffness U of the pile unit can be calculated according to the formula (3-1) ⁇ (3-3), but the h in the formula should be replaced by the length L of the pile mud; the bending moment and shearing force of the pile unit can be based on the unit side
  • the displacements ⁇ and 4 are calculated according to the formulas (3-4) to (3-7).
  • the longitudinal overall stiffness of the inclined pile unit is:
  • the horizontal displacement of the pile top has little difference with the bending moment generated by the straight pile and the fork pile, but the fork pile will generate axial force.
  • the main influencing factors of the horizontal displacement of each pile top by temperature difference are: 1 temperature difference longitudinal displacement zero line (temperature difference longitudinal displacement zero line refers to the transverse line with no longitudinal displacement near the middle of the platform when the temperature difference occurs in the dock) distance Y(m); 2 years minimum ⁇ maximum monthly mean meteorological temperature t, ⁇ t 2 V; 3 concrete composite shrinkage equivalent cooling range t cX ⁇ t c2 . C ; 4 The weather temperature V after the installation of the longitudinal beam during construction.
  • y, , , u [ ⁇ are the longitudinal coordinate and horizontal stiffness of the first straight pile and the first pile.
  • the displacement of the top of the pile is also related to the temperature of the longitudinal beam of the pile when the pile is piled. Because of the small cross section of the pile and the common steel, the average temperature of the short section is large, so consider the connection when the pile is piled up. The beam temperature effect is more complicated. However, construction techniques can be used to eliminate the adverse effects of the temperature difference deformation of the beam when the pile is piled.
  • the construction measures adopted are as follows: 1 If the meteorological temperature is high when the pile is piled, it is better to use the method of splashing water to reduce the temperature of the longitudinal contact beam and then clamp the pile; 2 if the temperature during the installation of the longitudinal beam is lower than the temperature when the pile is installed, Before the longitudinal beam is installed in the long section wharf, the longitudinal pile-girder beam can be relaxed every 40 ⁇ 60 meters to release the temperature difference stress generated by the pile.
  • yj u, ⁇ are the longitudinal and horizontal stiffness of the first straight pile and the first oblique pile, respectively. If the longitudinal horizontal joint force of the wharf is ⁇ , then the longitudinal horizontal displacement produced by the wharf is:
  • the internal force of the pile top can be treated as an external load.
  • the pile top reaction force can be distributed to the longitudinal beam according to the simply supported beam method. Since the internal force of the longitudinal beam generated by the temperature difference and the longitudinal horizontal load is not large and does not control, the internal force of the longitudinal beam can be approximated.
  • the pile bending moment reaction force is generated on the stringer M z, may be approximated by taking the middle of both sides of the support sill moments M z / 2, the inner edge of the support stringer bending moment M z is determined to take.
  • the longitudinal section axial force generated by the long segment structure due to the temperature difference is sometimes large, and the longitudinal beam and panel design can be considered.
  • the maximum axial force of the cross section of the platform occurs at the zero position of the longitudinal displacement of the temperature difference.
  • the horizontal stiffness of the inclined pile and the longitudinal temperature difference displacement pay attention to the sum of the horizontal forces of the piles on the zero line side of the longitudinal displacement of the temperature difference, and the axial force of each longitudinal beam and the panel can be shared according to the area ratio.
  • the internal force of the pile cap can be directly determined by the static balance method according to the reaction force of the pile top.
  • the action of the reaction force of the pile on the top of the pile under the temperature difference and the horizontal load can be decomposed into two directions of vertical and horizontal.
  • the vertical reaction force of the inclined pile can be applied to the horizontal frame as the additional vertical force of the horizontal load, and the internal force is calculated according to the lateral frame and participates in the combination of load;
  • the level of the beam For the action calculation, the lower beam can be regarded as a continuous beam supported on the longitudinal beam joint. The support is carried by the lower beam working with the longitudinal beam downward cantilever, and the upper beam can be regarded as a three-sided constrained plate.
  • the horizontal bending internal force of the lower beam can be calculated according to the continuous beam and then adjusted according to experience; the lower beam of the support, ie the lower cantilever of the longitudinal beam, should be equipped with the vertical reinforcement of the longitudinal beam to meet the cantilever bending requirements of the bearing reaction force.
  • the vertical reinforcement distribution range may be the width of the longitudinal beam plus half of the width of the lower beam on both sides; the bending moment and tensile force generated by the reaction force of the pile top against the upper and lower beam joints shall be arranged vertically within 3 ⁇ 6 times of the width of the beam on each side of the pile.
  • the steel bar bears; because the horizontal stiffness of the lower beam is much larger than the horizontal stiffness of the upper beam, the upper beam does not have to enhance the horizontal bending resistance.
  • the horizontal shearing stirrups of the lower beam, the connecting stirrups of the upper and lower beams, the horizontal bending reinforcement bars on both sides of the lower beam and the cantilever bending reinforcement bars under the longitudinal beams are all determined by calculation.
  • the analysis shows that: the beam is less resistant to the longitudinally stressed diagonal piles, and can meet the requirements within the normal reinforcement range. 3.6 Treatment after the expansion joint is closed
  • the above calculation method according to the single segment structure is suitable for the case where the longitudinal deformation amount does not reach the expansion joint.
  • the longitudinal force or temperature difference can be calculated in stages.
  • the longitudinal force or the temperature difference should be staged one by one to reach the closed state of the expansion joint.
  • the incremental longitudinal force or temperature difference in each stage is calculated according to the whole segment structure of the closed area, and finally the internal force is superimposed.
  • the increments of the longitudinal force or the temperature difference can be different, as long as the expansion joint is just enough to meet the closed state, the incremental increments can be divided according to the calculation. According to the linear superposition principle, the internal forces and deformations obtained by the final superposition are always equal.
  • the tether force can be divided into two stages.
  • the first stage is the tethering force that is just closed, and is calculated as a single segment.
  • the second stage is the difference between the total tethering force minus the first stage tethering force, calculated according to the two structural segments. Finally, the internal force is superimposed.
  • the beam section is as follows:
  • X(m) is based on the equivalent temperature difference of concrete shrinkage of 5 ⁇ 15 °C, the meteorological temperature difference is 3 °C, the highest is 30 °C, the longitudinal beam installation temperature is 20 °C; when the load is under the longitudinal horizontal force of 8000kN, The longitudinal calculation of the structure is as follows:
  • the overall stiffness of the unit is:
  • the internal force of the pile cap generated by longitudinal load can be ignored.
  • the bending moment is taken as 0; the inner and outer bending moments of the second row of longitudinal beams are all taken as 83 kN.m.
  • the temperature difference between each rail beam area is:
  • the ship's force is one of the main loads of the high-pile wharf.
  • the distribution of the lateral component on each row of shelves is a prerequisite for the quay structure to be simplified into the calculation of the frame.
  • the lateral component of the frame is the structure of the frame.
  • the calculation results have a greater impact.
  • the distribution of lateral component in each row of racks is calculated according to the elastic support rigid beam method (hereinafter referred to as the rigid beam method). This method is simple to apply, and the general situation can be determined by table.
  • the width and length of the wharf platform vary greatly. The width of the platform can be from less than 20m to more than 50m, and the length of the segment has reached 95m or even longer.
  • the horizontal stiffness of the pile foundation is also higher than that of the pile foundation.
  • the traditional small-diameter square piles are multiplied; whether the ratio of the section length to the platform width is large, the horizontal rigidity of the rack is large, and whether the wharf with a section length of 200m or more is still available.
  • the rigid beam method or how to calculate also needs to be studied.
  • the invention studies the distribution problem of the lateral component on each row of shelves, and solves the following two problems: 1. Under what conditions, the rigid beam method can be used, under what conditions the elastic beam method should be adopted; When the shelf is determined, how many spans the segment exceeds has little effect on reducing the horizontal force of the ship assumed by the shelf, thereby determining the length that the structural segment should not exceed.
  • the segmental horizontal relative flexibility coefficient of the segmented platform relative to the horizontal stiffness of the frame can be expressed by the dimensionless parameter 4 / (E / a), where is the horizontal stiffness of the shelf (kN/m), L is the distance (m) of the segmented two edge racks, E is the calculated modulus (kN/m 2 ), / is the horizontal moment of inertia (m 4 ) of the superstructure, a is the shelf spacing (m). Since the control internal force of structural calculation generally occurs on the edge 1, 2 ⁇ truss, the most unfavorable action point of the ship impact force or mooring force on the structure is also the 1 and 2 ⁇ ribs.
  • the calculation of the elastic beam method can be solved by the internal force calculation software of the high-pillar wharf longitudinal beam (track beam). According to the actual logarithmic variation range of the relative softness of the segmentation level and the number of different spans, The distribution coefficient of the lateral component of the 2 ⁇ truss according to the elastic beam method is shown in Table 4-1-1.
  • Table 4-1-1 Calculate the lateral component distribution coefficient of the shelf according to the relative softness of the segment level and the number of spans
  • the allowable error of the internal force of the structure is 5%.
  • the condition of the rigid beam method can be determined. Due to the calculation of the horizontal force distribution of the shelf Determine the relative stiffness of the beam and the support. Therefore, it is only necessary to determine the relative horizontal stiffness of each frame for the rigid beam. When the horizontal stiffness of each frame is equal, it is not necessary to calculate the lateral stiffness of the frame. Check the table to confirm.
  • the elastic beam method is relatively complicated, some designers are unwilling to adopt it. Therefore, it is necessary to explore under what conditions the elastic beam method should be used, otherwise the structural design may exceed the allowable error. Considering that the design internal force of the wharf structure is controlled by the second truss rack in most cases, it is generally required that the second truss rack error is not more than 5%. However, the calculation error of the first truss rack should not be greater than 10%, otherwise it will easily lead to the internal force combination of the first truss rack exceeding the engineering allowable range. In this paper, the error of the second frame is not more than 5%, and the error of the first frame is not more than 10%.
  • the conditions calculated by the elastic beam method are determined. After analysis, it can be obtained: When lg[ 4 /(E/a)] > 1.7, kL 4 /(EIa) > 50, the elastic beam method should be used. The comparison of the calculation results is shown in Table 4-1-3.
  • the rigid beam method can be used when 4 /(E/a) ⁇ 25; the elastic beam method should be used when 4 /(E/ fl ) >50; when /(E/a) In the range of 25 ⁇ 50, the elastic beam method should be used when there are conditions. If the first beam frame distribution coefficient should be increased by 10% according to the rigid beam method, the second frame frame distribution coefficient should be increased by 5%.
  • the single-span horizontal relative flexibility coefficient of the dock platform can be expressed by the dimensionless parameter fe 3 /(EI).
  • EI dimensionless parameter
  • the maximum span of the lateral component of the frame, the design segment should not exceed the span. Otherwise, the general economic and technical effects are not good.
  • the design to determine the maximum segment length should also consider the requirements of longitudinal temperature difference deformation and concrete shrinkage deformation.
  • the horizontal moment of inertia of the superstructure should be calculated according to the plate beam structure composed of the wear layer, the panel and the longitudinal beam.
  • the horizontal stiffness of the truss can be solved by the lateral truss calculation software, which is the reciprocal of the horizontal displacement of the truss produced by applying a unit horizontal force (such as the unit thrust of the ship) at the axis of the beam.
  • the change of the horizontal stiffness of the frame is not sensitive to the horizontal force distribution of the frame. It is not necessary to adopt a very accurate calculation method.
  • it can also approximate the vertical displacement of the pile top. According to the axial direction of the pile top, The lateral stiffness and the inclination angle of the pile are determined.
  • a pier platform is 16m wide, the frame spacing is 8m, and the segment span is 9 spans.
  • the offshore deep water long section structure can reach more than 200m, which is obviously different from the conventional structure.
  • the displacement and internal force generated by the temperature difference are different with the different positions of the pile in the segment.
  • the distribution state is: The temperature difference in the middle of the segment is the displacement of the pile and the internal force is zero.
  • the piles at both ends of the segment have the largest displacement and internal force, and the transition is in accordance with the curve.
  • the high-pile wharf structure usually adopts the following layout scheme:
  • Pile foundation arrangement usually adopts each row of fork piles to be arranged in the lateral direction, but the lateral deviation angle is large (usually 18 ⁇ 26°). 0
  • the longitudinal resistance of the pier can be improved by using the fork pile with large lateral angle.
  • the construction is also easy to avoid hitting the pile.
  • the lateral yaw angle is not large (usually less than 26°)
  • the lateral resistance of the wharf is not greatly affected. Therefore, for the conventional segmented structure, the cross pile has a large lateral yaw angle. Economically reasonable.
  • the longitudinally-forced fork piles may also be arranged at the ends of the segments (usually at the second row of shelves) as needed to resist longitudinal horizontal forces. Due to the small deformation caused by the conventional section temperature difference, the axial force and bending moment generated by the pile can be neglected, and the internal force of the pile and the beam is usually the largest at the second row frame, so the longitudinal force-bearing fork pile is arranged on the second row frame. It is economically reasonable to achieve the vertical horizontal resistance of the pier and the maximum internal force of the pile and the beam.
  • the joints are generally connected, and the bending resistance of the piles is used to improve the horizontal resistance of the pier and enhance the horizontal stiffness. Because under the conventional segmentation conditions, the number of rows of the rows in the section is small, the horizontal force of the pile is large, and the slope of the pile allowed by the offshore deep-water wharf pile is small, and the axial force resistance level of the fork pile is utilized. The effect of the force is poor, so it is generally necessary to use the bending resistance of the pile to improve the horizontal resistance. In order to make full use of the bending resistance of the pile body to improve the horizontal resistance Force, the top of the pile needs to be connected by a rigid joint.
  • the concrete pile can not meet the requirements of the horizontal force of the dock. It is also necessary to use steel pipe piles.
  • the steel pipe pile can be used to increase the pile inclination and utilize the high-strength bending resistance of the steel pipe pile. Meet the horizontal resistance requirements of the terminal.
  • the spacing of the racks is generally arranged at equal intervals.
  • the number of conventional segmented racks is small. If the racks are arranged with unequal spacing, the reduced engineering quantity has little advantage compared with the increased construction difficulty.
  • the equal spacing arrangement can reduce the type of components, facilitate construction and improve construction speed. .
  • the segment length of the structure is technically mainly controlled by the pile axial force or pile bending moment generated by the temperature difference.
  • the following problems need to be considered:
  • the length of the pile top will limit the length of the section of the pier.
  • the bending moment of the pile temperature difference generated by the hinged form is small, which can increase the segment length and reduce the horizontal load sharing force, thereby compensating for the improved level of resistance and rigidity of the pile top.
  • the greater the water depth and the greater the proportion of the inclined piles the worse the advantages of the pile top joints.
  • the pile top joints may have advantages.
  • offshore deep-water wharfs are often constructed under conditions of high wind and waves. In fact, it is difficult to make the pile tops just connected.
  • Some piers are swaying more, but the horizontal displacement calculated according to the pile top just is less than the measured displacement value. It may be that the construction failed to make the top of the pile just connected. Since the hinged calculation mode allows the connection point to rotate, it is more suitable for construction under wind and wave environment, and is more suitable for the connection form of offshore engineering.
  • the present invention adopts the following technical solutions:
  • the fork piles other than the longitudinal displacement zero line of the temperature difference are arranged at a small lateral angle (such as the B section 3 in Figure 1) to reduce the axial force of the fork pile caused by the longitudinal expansion.
  • fork piles arranged in pairs should be used. When all the concrete piles are difficult to resist horizontal horizontal loads, the ends of the segments can be fixed.
  • the fork piles in the circumference are replaced by steel pipe piles with a large inclination (Fig. 5, Pile F 5).
  • the hinged form of the pile top can be divided into sections with different connection structures: the piles at the top of the pile are less than the strength of the pile body.
  • the piles at the top of the pile can be used in the conventional way, that is, the pile top can be extended into the upper concrete by 5 ⁇ 10cm.
  • the hinge joint of the pile top should adopt an innovative hinge joint structure for reducing the bending moment of the pile top, which will be described in Article 6 of the present specification. New connection structure.
  • the PHC piles are selected as an example for calculation and comparison.
  • the bending moment of the pile increases rapidly as the height of the mud decreases.
  • the maximum bending moment of the pile is generally more than doubled when using the joint; the bending moment of the mud is 30% ⁇ 60% smaller than that when the joint is used ; The ratio increases.
  • the axial force of the pile is proportional to the axial reaction coefficient of the pile top, the slope sin(a) and the lateral deviation angle S i n ( e );
  • the horizontal resistance of the rigid piles increased by the bending moment of the piles decreases with the height of the piles, the slope of the piles, and the axial stiffness of the piles.
  • the pile foundation also produces the temperature difference axial force.
  • the axial force generated by the temperature difference has little effect on the structure within the traditional wharf segmentation, and the design is negligible.
  • the calculated temperature difference is considered to be 50 ⁇ (the temperature difference is not large for a conventional wharf that does not take measures to reduce the temperature difference), and the temperature difference at the segment edge is shifted to:
  • the height on the mud is 20m, and the slope is 4:1. It is expressed in bold italics and is only used for theoretical comparison.
  • the ratio of the maximum temperature difference between the axial force and the bearing capacity of the pile with a pile diameter of 1.0 m is 0.46
  • the ratio of the maximum temperature difference between the axial force and the bearing capacity of the pile with a diameter of 1.2 m is 0.47.
  • the height of the mud is 5m, and this height is often encountered in the docking piles in the bank of the bank
  • the mud surface stiffness coefficient C takes a large value of 145/m
  • the measured axial stiffness coefficient is highly discrete.
  • the C value of the less piles reaches this value; the bearing capacity is 1.0m pile 6250kN and 1.2m pile 7500kN respectively, and the measured statistics are less than the pile capacity of the bearing capacity, because the state of the pile is traditional engineering design can be allowed, in practice This kind of pier in the pile state has not caused obvious damage, so it can be considered that the axial displacement caused by the design allows the temperature difference to be less than 4 ⁇ 5mm and the axial force is less than 50% of the carrying capacity. (It can be used as a double-control standard for temperature difference axial displacement and axial force of foundation piles when designing long section structure).
  • the pile axial force is proportional to the axial reaction coefficient of the pile top and the pile inclination 3 11 ( ( 1 ) and the lateral deviation angle 3 ⁇ 1 ⁇ ).
  • the pile axial force generated by reducing the temperature difference should be minimized.
  • the lateral deflection of the fork pile Due to the large temperature difference displacement near the two ends of the long segment structure, if the longitudinal force-bearing fork pile is arranged, a large temperature difference axial force is generated, so the longitudinal force-bearing fork pile cannot be arranged.
  • the long segmented structure can reduce the horizontal force of the pile, which is beneficial to the use of concrete piles instead of steel pipe piles.
  • concrete piles should be used.
  • the fork piles at both ends of the segment near the edge of the shelf area can be replaced by steel pipe piles with larger inclination. (Figure 1 F zone pile 5).
  • the steel pipe piles should be increased in slope, and the increased slope of steel pipe piles can be used to increase the horizontal resistance of the piles, so as to reduce the length of the steel pipe piles and replace the length of the fork piles and increase the pier.
  • the level of resistance Generally speaking, the number of steel piles in the row of the piles near the two ends of the section is reduced by the proportion of the piles as the length of the sections increases, that is, the longer the section length, the more the proportion of the steel pipe piles is used. low.
  • the size and length of the steel pipe pile replacement fork pile are determined by structural calculation.
  • the longitudinal horizontal resistance is weak, and the longitudinal seismic requirements cannot be met. For this reason, the longitudinal displacement of the temperature difference is 25m and is not larger than the segment.
  • the length of 1/6 of the length (such as area A in Figure 1) is arranged to form a longitudinally loaded pile with an angle of less than 45° with the longitudinal direction (Fig. 1 Pile 2). If necessary, a part of the bearing capacity can be spared.
  • the straight piles are arranged in longitudinally stressed piles to enhance the longitudinal horizontal resistance of the pier.
  • the number of fork piles in the length of the intermediate zone is large, and it can generally meet the longitudinal resistance requirements of the structure after the longitudinally loaded oblique pile; 4 long section piers have more transverse cross-pile piles resisting horizontal forces at both ends, so when After these intermediate row of fork piles are replaced by longitudinal force, the horizontal horizontal force of the intermediate row frame can be transferred by the two side frame, which has little effect on the horizontal horizontal resistance of the intermediate frame.
  • Cross-pile piles in the middle area and straight piles with sufficient bearing capacity can also be changed to longitudinally-loaded inclined piles according to requirements.
  • the amount and slope should be calculated according to the structural resistance to longitudinal horizontal force and longitudinal seismic requirements.
  • the slope of the longitudinal pile can be smaller than the slope of the transverse fork pile.
  • the longitudinal internal force of the segmented edge pile should be less than 1/3 of the pile allowable value to reserve the internal force of the pile allowed by the temperature difference.
  • the minimum lateral declination of the fork pile is related to factors such as pile diameter, pile spacing and pile deviation.
  • Piling deviation should be considered: the top level deviation of the pile top, the azimuth deviation, the pitch angle deviation, the left and right swing angle deviation, etc., under the premise of ensuring that piles will not be hit, the transverse angle of the pile should be minimized.
  • the angle should not be greater than 10 ⁇ 18°.
  • Piling construction should take measures to ensure that the azimuth of the inclined pile, the deviation of the left and right swing angles, and the deviation of the adjacent straight piles should be paid attention to ensure that the piles do not hit the pile and the error is controlled within the allowable range.
  • the calculated temperature difference of a wharf is 50 °C
  • the skew of the fork pile is 4: 1
  • the axial displacement of the pile is allowed to be 4 mm.
  • the minimum lateral angle of the fork pile is 10°
  • the allowable segment length is approximately:
  • the long segment structure of this example can take a horizontal angle of 18° in the middle of 212m, without reducing the lateral angling; and in the range of 212 ⁇ 378m outside the zone to the edge of the segment, the lateral reduction should be adopted.
  • the angling measures are such that the lateral angle is not more than 10°.
  • the segment length L should satisfy kL 4 1 ⁇ ) ⁇ 150 or span " ⁇ 3.5 * [EI /(ka')] 02s .
  • N 2 The axial force of the inclined pile when the axial force of the inclined pile is equal to the joint
  • Table 5-3-1 Increased horizontal resistance coefficient of just-connected piles
  • lZSlOO/llOZN3/X3d is called OAV 11 6 20 1.0 10000 130 790 904 819 1.10
  • the height of the pile is generally greater than 10m.
  • the inclined pile generally adopts a 4:1 slope.
  • the number of inclined piles/straight pile The number is generally greater than 2/5.
  • the horizontal resistance ratio of the pile-rigid frame is roughly between 1.1 and 1.4.
  • the pile with a diameter of lm and a slope of 6:1 is used.
  • the horizontal resistance ratio of the pile-rigid frame is smaller, between 1.1 and 1.25. If the pile diameter is 1.2m and the slope is 6:1, the horizontal resistance ratio of the pile-rigid frame is between 1.1 and 1.4. . Based on the above situation, it is known that the horizontal resistance ratio of the offshore rigid-deck large-decked piles is mostly between 1.1 and 1.4.
  • the length of the segment is controlled by the bending resistance of the pile.
  • the ratio of the length of the joint to the joint is determined according to the principle that the longitudinal bending moment of the pile is equal. Since the temperature difference deformation is linearly proportional to the bending moment, the ratio of the maximum bending moment of the rigid pile to the maximum bending moment of the hinged pile under the same displacement condition can also be taken as the ratio of the length of the joint to the joint.
  • the ratio of the maximum bending moment of the rigid pile and the hinged pile decreases with the increase of the mud height of the pile, the increase of the horizontal stiffness coefficient m of the foundation, and the decrease of the pile diameter, but the variation range is not very large, generally the maximum bend The moment ratio is in the range of 2.3 to 2.7. From this, it can be known that the length of the pier section can be increased by more than 2.3 times in the form of an articulated pile.
  • Table 5-2-2 is calculated according to the ideal articulated form.
  • the conventional pile top hinge structure is not applicable.
  • an innovative articulated connection structure is required to achieve the design requirements for long segmented articulation (see the next section).
  • the ratio of the length of the joint of the hinge should be reduced according to the joint effect of different hinge structures, because the bending moment of the pile top is not the bending moment of the mud.
  • the minimum take-off factor can be taken as 0.8, considering that the hinged structure is always non-ideal hinged, but the hinged pile can ensure that the pile top does not suffer from bending damage, and the pile top moment is against the mud. The bending moment has little effect. It is recommended that the reduction factor of the ratio of the hinge to the length of the joint is 0.8 ⁇ 0.9 depending on the hinge effect.
  • the top of the pile should also check the corner of the hinge structure, and the maximum relative rotation angle of the pile top is required to be smaller than the allowable angle of the hinge structure.
  • the total bending moment of the pipe pile is formed by superposing the transverse bending moment and the longitudinal bending moment by vector, if the pile body allows The bending moment is ⁇ 1, the transverse bending moment standard value is M A , then the longitudinal allowable bending moment standard value is M z
  • the long segmented structure requires the pile foundation to have a certain longitudinal allowable bending moment value.
  • the design should take into account the longitudinal and transverse forces of the pile foundation. Generally, the transverse bending moment of the pile should not exceed 0.8M, so that the longitudinal longitudinal bearing can withstand bending moments. Not less than 0.6M.
  • the following analysis of the longitudinal internal force of the temperature difference that can be generated by the traditional dock under the condition of the pile top can be used as a reference for controlling the internal force of the temperature difference in the long segment structure.
  • the calculated temperature difference is considered to be 50 ° C, and the temperature difference at the segment edge is 17.5 mm.
  • the axial force generated by the pile displacement is shown in Table 5-3-3.
  • the 1 row frame adopts the horizontal resistance improved by the just-connected pile: Calculated by Yigong software, the frame is under the action of 1000kN horizontal force: For the just-connected condition: displacement 10.75mm, maximum pile pressure 847kN; for articulation: displacement 11.23mm, maximum pile pressure 872kN.
  • the allowable displacement of the pile top is calculated to be 23mm.
  • the length of the segment is calculated to meet the requirement of effectively reducing the horizontal force of the frame.
  • the transverse maximum bending moment under the straight pile is calculated to be 70kN.m, the minimum axial force is taken as 0, and the gauge bending moment is 700kN.m.
  • the longitudinal bending moment of the pile is calculated.
  • the standard value is
  • the bending moment of the pile top caused by the temperature difference is also taken as 500kN.m, and the allowable displacement of the pile top is calculated to be 58mm.
  • segment length of this example is severely limited by the width of the platform, so that increasing the length of the pier segment cannot effectively reduce the horizontal force of the frame. If there is no special requirement in use, only considering the structural cost, when the length of the segment is greater than 176 meters, the project cost can not be significantly reduced, so it should be 176m.
  • the longitudinal beam of the construction is placed in a simple supported state before the structure can form a longitudinal overall force.
  • the self-weight of the panel can be installed after the longitudinal integral force of the structure is formed, due to the panel
  • the longitudinal load sharing of the racks caused by the self-weight is not large, and the uniform load distribution is not large. Therefore, it can be approximated that the axial forces of the rows of the piles generated by the self-weight are also not much different.
  • Example 5-3-1 the loads shared by the first and second rows are the largest.
  • the maximum internal force of each row of shelves is calculated from the edge under the load of 8 cross-door loads. See Table 5-4-1.
  • Table 5-4-1 Table of maximum bearing reaction force (kN) of track beam under door load
  • a rough comparison of the economics of reducing the distance between the first spans is as follows: Assuming that the live load accounts for 50% of the total load, reducing the spacing of the edge racks can reduce the pile force by 7.5%. Assume that the length of the pile under the mud is twice the length of the pile on the mud. The economic comparison assumes that the length of the pile under the mud is approximately proportional to the axial force of the 1/2 pile. The reduction of the pile axial force by 7.5% can reduce the pile length by 2.5%, which can reduce the pile foundation. The cost is about 1.5%. According to the pile foundation, the total cost of the structure is 40%, which can save about 0.6% of the project cost.
  • the high-pile wharf hinge structure only adopts the method of lowering the height of the pile top into the lower beam or the cap pile.
  • This conventional hinge connection structure cannot guarantee the free relative rotation between the pile top and the lower beam or the cap pile, which is actually An indeterminate connection between the rigid joint and the hinge, the pile top can still be damaged when the longitudinal displacement is large.
  • the conventional hinge structure is only suitable for the bending moment of the pile top calculated according to the rigid joint. The condition of the pile body's resistance to bending. In the past, the length of the conventional wharf section was small, and the bending moment generated by the temperature difference deformation was always less than the bending resistance of the pile body. Under the condition that the pile top would not be damaged, although the design was calculated according to the hinge, the actual pile top was partially connected. The force of the dock is beneficial and belongs to the design safety reserve.
  • the long section pier adopts the form of pile top connection
  • the temperature difference will produce a large pile top bending moment, which will often become the control condition for limiting the length of the section.
  • the long section structure should generally be hinged. Form, but because the conventional hinge structure can not guarantee the required free rotation angle of the pile top, it can not guarantee that the bending moment of the pile top is less than the bending resistance of the pile body, so it can not be used for the bending moment of the pile top to be greater than the bending resistance of the pile body according to the calculation of the joint connection.
  • the long segment of the ability is near the edge of the two edges, which will greatly limit the segment length.
  • the longer the segment length the smaller the horizontal force the frame receives, and the more favorable it is to replace the steel pipe pile with concrete piles;
  • the fork pile is made of steel pipe pile
  • the amount of steel pipe pile does not increase with the increase of the length of the section, and the increase of the length of the section is also beneficial to reduce the proportion of the steel pipe pile.
  • the conventional pile top hinge structure cannot be used for the area where the bending moment of the pile top is greater than the bending resistance of the pile body in the calculation of the joint connection, it is necessary to propose a new joint connection technique suitable for the long section structure.
  • there are many forms of articulated structures used in highway, railway and other industrial projects but there is no suitable structure for the high-pile wharf pile top hinge.
  • the long section wharf needs to solve the new hinge structure which can reduce the bending moment of the pile top. .
  • the bottom plate should be made of 20 manganese steel and other materials with a thickness of about 10 ⁇ 20mm.
  • the outer diameter of the outer diameter should be larger than the outer diameter of the shear steel pipe (031) by more than 3 ⁇ 5cm, so as to pour the concrete inside the pile.
  • the steel cage should be taken as small as possible.
  • the main cage of the steel cage (021) should be made of grade 3 steel or grade 2 steel with a diameter of not less than 28mm to reduce the diameter of the cage and increase the allowable gap of the joint surface;
  • the amount of ribs should meet the tensile requirements of the pile top and the maximum bending moment should be less than the allowable bending resistance of the pile.
  • the tensile main rib should be surface-slided (022) near the contact surface, and the film material can be wrapped after applying the anti-corrosion oil.
  • the purpose is to eliminate the concrete gripping force to increase the allowable gap of the contact surface; the total length of the sliding treatment section should be According to the calculation of the allowable gap amount required for the calculation; the length of the upper and lower sections not subjected to the sliding treatment needs to meet the anchorage length requirement; because the diameter of the reinforcement cage is small, it may be considered to anchor the upper section of the tensile main rib to the pile cap or the lower beam.
  • shear steel pipe should use thick-walled seamless steel pipe, should choose 20 manganese steel and other materials, the thickness should not be less than 30mm, the cross-section of steel pipe should meet the shear requirements of the pile top;
  • the exterior should also be surface-slided.
  • the film material can be wrapped with anti-corrosion oil in order to eliminate the concrete gripping force and avoid uncontrollable pile top bending moment.
  • the medium plate should be made of 20 manganese steel and other materials, the thickness can be about 30mm; the inner diameter should be larger than the outer diameter of the shear steel pipe by l ⁇ 2mm; the outer diameter should be larger than the inner diameter of the bottom plate not less than 50mm, to meet the requirements of the receiving pressure;
  • the outer edge should be made into a slope (042), and the slope should be about 5 ⁇ 10°. It should meet the required rotation angle of the pile top; the slope length should be greater than 100mm; the width of the slope top platform should be calculated according to the local pressure and should not be less than 50mm.
  • the flexible anti-corrosion filler (063) can be filled in the outer space of the middle plate, and the top plate (051) is installed after applying the structural adhesive on the top of the middle plate.
  • the top plate should be made of 20 manganese steel and other materials.
  • the thickness of the top plate in contact with the middle plate should not be less than 20mm.
  • the inner diameter should be larger than the outer diameter of the shear steel pipe by l ⁇ 2mm, and the outer diameter is the same as the pile diameter.
  • the anchoring ribs should adopt 2 grade steel, the bending angle can be between 30 ⁇ 60°; the shearing plate height can be about 50mm.
  • the anchoring ribs and shear plates should be able to resist the shearing force of the pile top and the friction of the steel pipe.
  • the amount of reinforcement and the size of the shear plate are determined by calculation.
  • the horizontal steel bars above the top plate cannot pass through the shear plate, the horizontal steel bars can be welded to the top plate or the shear plate.
  • the contact strength between the roof and the steel pipe can generally resist the pile top shearing force, such as steel pipe diameter 0.2m, roof plate thickness 2cm, according to 20 manganese steel
  • the length of the concrete pipe embedded in the lower pile can be determined by the length of the 1/2 pile.
  • the top of the top plate to the bottom of the pile shall be covered with flexible anti-corrosion material (064).
  • the anti-corrosion material shall be selected from low-stiffness material.
  • the thickness may be about 5 ⁇ 10mm.
  • the wrapping range shall exceed the top surface of the top plate and the bottom surface of the pile cap (or lower beam). The distance not less than 20 mm and extending under the bottom plate should meet the anti-corrosion requirements.
  • the width of 041 can be calculated according to Fig. 24.
  • the inner edge radius of the plate is r
  • the radius of the top edge of the slope is R
  • the local pressure area of the rotation is shown by the shadow in the figure.
  • the shadow area is:
  • the shear force Qn is taken from the pile top shear force Q plus 0.05 pile top axial force N, acting on the pile top;
  • the frictional force of the steel pipe and the roof side is P;
  • T is the design tension of the anchor steel bar;
  • P is the anchor steel bar bending Angle, shear plate side reaction force o
  • fc the concrete axial compressive strength
  • a is the distance between the steel pipe and the top plate side friction force P to the edge of the top plate
  • b is the distance from the intersection of the anchor steel bar floor to the edge of the top plate
  • c shearing The distance from the plate to the anchor steel bar floor
  • d is the distance from the side reaction center to the pile top shear force Qn.
  • the area resisting the direction of the shear force ⁇ should meet the requirement of resisting the shear force Qn.
  • the area of the shear plate is determined by the following formula:
  • the anchor steel bar can be used as the torque axis of the side reaction force center O.
  • the anchoring force T can resist the shear force Qa to determine the o-point torque.
  • the horizontal component force of T can be ignored.
  • the force T1 can be determined by the following formula -
  • Anchored steel bars should meet the pull-out requirements of the side friction force P between the top plate and the shear-resistant steel pipe.
  • T2 P*a/(b*sin 3 ) 6-1-6
  • T Qn*d/(c*sin ⁇ )+P*a/(b*sin ⁇ ) 6-1-7
  • the relative rotation angle required for the ID pile top is determined according to the calculation of the maximum rotation angle ⁇ of the top of the hinged pile.
  • the amount of clearance required for the contact surface is determined by the distance from the tensile main rib to the top edge of the farthest slope multiplied by the maximum rotation angle, ⁇ :
  • ⁇ allows the amount of gap mm
  • P is the distance from the tensile main rib to the top edge of the farthest slope mm
  • ⁇ is the maximum angle of curvature
  • the total length of the sliding treatment layer required for the tensile main rib can be determined as follows:
  • ⁇ ⁇ *Es/ fyk-2La 6-1-9
  • ⁇ the total length of the sliding treatment layer required for the tensile main reinforcement
  • ⁇ the allowable gap amount m
  • Es is the elastic modulus of the steel bar kPa
  • fyk is the steel resistance
  • the tensile strength standard values kPa and La are the equivalent free lengths of the anchoring section, and the grade 2 steel can be approximated by 10d and the grade 3 steel can be approximated by 15d.
  • a is the area of the main rib resistance
  • n is the number of main ribs
  • fyk is the standard value of the tensile strength of the main rib
  • r is the radius of the top line of the middle slab.
  • the inclined pile articulated form can be directly inclined, as shown in Figure 2c.
  • the new hinge structure proposed by the invention has considered the connection problem of the inclined pile.
  • the connection point of the inclined pile is the wrapping material of the long side of the thickened and thickened pile.
  • the lengthening wrapping material should extend out of the concrete, and the thickening wrapping material is for the purpose of ensuring the pile.
  • the amount of free rotation of the high side meets the maximum relative rotational angle requirement.
  • the construction method of the oblique pile connection is simple, the steel bar is made and straight As in the case of piles, it can be shaped and produced.
  • the treatment of inclined piles is very convenient. Because the long-segment structure is suitable for friction piles, the pile driving is generally controlled according to the height of the pile top, and there are not many cases of cutting pile heads. Therefore, the two types of inclined piles are connected.
  • the method is suitable for long segmented structures.
  • the new articulated structure has a certain amount of axial relaxation compared to the conventional hinge structure when subjected to the axial tensile force, which is considered to be advantageous for the long segment structure.
  • the pile tension will be reduced by the temperature difference.
  • the pile tension relaxation is favorable for the pile tension and has little effect on the pile compression.
  • the tensile force of the pile is not large or even tensile, so the pile top has less influence on the tension relaxation.
  • the longitudinal beam when the pile is under tension, the corresponding upper part has no load, the nearby beam does not produce the maximum positive bending moment, but has little effect on the positive bending moment of the distant beam, and the comprehensive analysis has less influence on the positive bending moment.
  • the tensile tension of the pile will increase the negative bending moment of the beam, considering that the panel can participate in resisting the negative bending moment and the longitudinal plastic beam can be partially plastically adjusted, the actual negative bending moment will not be adjusted. It has a great influence on the longitudinal beam. If there is concern about the influence of the negative bending moment of the beam, the negative bending moment reinforcement amount can be appropriately increased.
  • the new hinge structure produces a relative corner
  • the upper structure is raised, but because the contact surface is small, the amount of elevation generated by the rotation is small. Seen from the plane piles, the amount of elevation is gradually changing slowly, and the impact on the structure is very small. This is also the case when the large pipe piles are hingedly connected, and the amount of elevation may be greater than the new articulation. There was no problem in the middle.
  • the new articulated structure adopts the practice of increasing the sliding treatment section by the tensioned main rib.
  • This technology has been widely used in the prestressed structure of highway bridges and is a mature experience that can be used for reference. Since the concrete depth in the pile is generally 2 m, the sliding treatment section can extend more into the pile to reduce the height of the main rib into the upper concrete.
  • the joint bending strength of the pile top is beneficial to the structural stress, and is actually a safety reserve, when an excessively large horizontal force occurs or During the earthquake, the bending strength of the connection of the pile top will also play a role. Therefore, the joint connection of the pile top should have a certain bending resistance, but it should not exceed the bending strength of the pile.
  • the new hinge structure produces a lower bending moment than the traditional hinge structure, it is not ideal for articulation.
  • the design should consider increasing the maximum bending moment of the pile body properly, which can be multiplied by 1.1 to 1.2.
  • the new articulated structure has the following advantages - 1
  • the hinged pile works reliably, and the relative rotation angle allowed by the pile top is large.
  • the resulting bending moment of the pile top can generally be controlled within the range of the allowable bending moment of the pile body, which can meet the hinge requirement of the long section structure.
  • the bearing capacity of the 2 piles is reliable, and the pressure is transmitted directly to the top surface of the pile.
  • the concrete pouring in the 3 piles mainly bears the pile pulling force.
  • the tensile strength of the piles in the long section structure is not large.
  • the concrete depth poured in the pile generally only needs to meet the anchoring of the steel bars and meet the structural requirements.
  • the pile cap When the pile cap is used, because the diameter of the connecting steel cage is small, it can be extended into the longitudinal beam joint anchoring. Therefore, the height of the pile cap is small, generally it can take a small value of 60cm according to the construction requirements, which is conducive to improving the construction water level.
  • the top of the pile does not need to extend into the lower beam, which is beneficial to the bottom reinforcement of the lower beam directly passing through the top of the pile for convenient construction.
  • the 6-segmented structure adopts the hinged pile to better adapt to the situation that the pile top is difficult to connect under the harsh conditions of wind and waves, and is more suitable for the situation of the deep-water terminal in the open sea.
  • the long segmented structure can be calculated according to the load on the panel and transmitted to the panel and the panel to the longitudinal beam.
  • the longitudinal beam should be used as the lattice beam, pile cap or pile.
  • the top is calculated as a spatial lattice beam elastic support method for the elastic support. If calculated according to the plane beam method, if the parameters such as the elastic coefficient of the support can be reasonably determined, the results calculated by "passing from the longitudinal beam to the beam” or "from the beam to the longitudinal beam” are consistent.
  • the elastic modulus of the support of the plane beam method should be calculated according to the mode of transferring from a relatively small beam to a relatively large beam, so as to ensure the relative calculation.
  • the error is small.
  • the elastic modulus of the bearing of the plane beam method should be taken in the most unfavorable terminal load arrangement state, the ratio of the longitudinal beam load value to the settlement value of the bearing after considering the spatial influence, so that the calculation result is not in the most unfavorable load state. Accurate, but since the internal force is not designed to control the internal force, the structure will not be damaged.
  • the longitudinal beam of the long section structure it is better to adopt the mode of "transferring from the longitudinal beam to the beam" when calculating by the plane beam method.
  • the value of the elastic modulus of the longitudinal beam is not very sensitive to the internal force response of the structure under load. It can be determined by reference to the current high pile terminal specifications.
  • the horizontal horizontal load of the ship can be distributed on each of the rows of shelves according to the elastic beam method, and the load on the pier surface can be transmitted to each of the rows by the longitudinal beam support.
  • the lateral forces including the horizontal force, the vertical force, and the bending moment on the lateral plane
  • the load states of the adjacent shelves are basically the same, and the calculated deformation of the frame and the adjacent frame is basically the same, and the arrangement of the shelves can be ignored.
  • the longitudinal beam transmission force generated by differential deformation, so that the calculated truss can be simplified to a plane calculation.
  • the load on the adjacent frame can only be equal to or less than the maximum load, when the adjacent frame load is less than the calculated frame load.
  • the load of the calculated frame is shared by the stringers, so the calculation of the plane frame is usually safe.
  • the force of the long-segment structure of the frame is basically in accordance with the condition that is simplified into the calculation of the plane frame, so the calculation of the plane frame can be used.
  • the internal force calculation of the long section wharf structure can also be divided into two phases: construction period and use period.
  • the calculation of the construction period is the same as that of the conventional high-pile wharf;
  • the calculation of the use period can be divided into: (1) longitudinal continuous beam calculation, (2) overall calculation of the structure under longitudinal horizontal force and longitudinal temperature difference, and (3) horizontal force of each row of shelves
  • the distribution coefficient is determined, and (4) the lateral shelf calculation. The following points are calculated separately:
  • the longitudinal horizontal force shall take into account the longitudinal component of the cross-platform tension cable, the longitudinal component of the ship's impact force, the wave force of the water flow, the braking force of the door machine, and the possibility of impacting the blocking plate when the ship crosses the segmented platform tether.
  • Force, seismic force, other possible longitudinal loads and possible combinations; equivalent temperature differences due to concrete shrinkage and meteorological changes can be determined in accordance with the method described in Clause 2.
  • 3 Longitudinal earthquakes and door impact bumping plates can also be considered as single mass points according to the superstructure, and the spring stiffness is calculated according to the longitudinal stiffness of the structure considering the seismic enhancement coefficient.
  • the value of the axial stiffness of the pile top is sensitive to the calculation result (the pile axial force is roughly proportional to the axial stiffness of the pile top), so the axial stiffness of the pile should be measured.
  • the distribution coefficient of the horizontal force of each row of shelves shall be determined according to the method described in Article 4.
  • the main points of calculation are as follows:
  • the long-segment structure should adopt the elastic support continuous beam method to determine the horizontal force distribution of the frame.
  • the stiffness of the continuous beam can take the horizontal bending stiffness of the upper structure panel, longitudinal beam and wear layer to work together.
  • the modulus of elasticity can be calculated using the shelf software, that is, the horizontal force is applied at the center of the panel, and the ratio of the horizontal force to the horizontal displacement is determined.
  • the long-segment structure of steel pipe pile fork pile frame, concrete fork pile fork pile frame, and the intermediate longitudinal force pile pile frame have different horizontal stiffness, and different bearing elastic coefficient should be used to calculate.
  • the lateral stiffness of the intermediate longitudinally loaded pile frame can also be calculated by taking the zero value safely.
  • the calculation software of the longitudinal pile of the high-pile wharf can be used, and the reaction force of the support calculated by the continuous beam of the elastic support is the distribution of each row of shelves. The horizontal force.
  • the main points of the calculation of the lateral arrangement are: 1 In a wharf section, the two outer rows of the shelves, the outermost echelons that change the arrangement of the pile foundations, and other shelves that may control the internal forces are calculated; 2 different pile foundations The layout should be calculated according to different calculation formulas; 2 the difference between the traditional hinge structure of the middle section and the new hinge structure of the outer section of the two sides can be ignored, and all of them are simplified to the hinge calculation; 4 the lateral section of the longitudinal section of the longitudinally arranged diagonal pile should be calculated.
  • the combined force and the combined moment of the vertical reaction force of all piles are basically zero. 5
  • the vertical force acting directly on the shelf is carried by the gantry.
  • the horizontal force can exert all direct force at the point of action, and the force of the uniform distribution along the axis of the panel is transmitted to the other trusses. It should be equal to the horizontal force shared by the rack.
  • the axial force generated by the temperature difference deformation should be fully considered in the calculation of the pile body, but the influence on the bearing capacity of the foundation should be considered according to the following factors:
  • the axial reaction coefficient of the pile provided by the test is the reaction coefficient after multiple cycles of stability in the short term during the test, and the temperature difference deformation is the slowly applied deformation during the year. Because the deformation stiffness of the soil is closely related to the loading speed, the actual The temperature-dependent deformation stiffness of slow loading is generally much smaller than the stiffness of the test. Therefore, the axial reaction coefficient provided by the test is much larger than the actual temperature difference.
  • the actual friction pile axial force can be generally discounted by 0.3 ⁇ 0.5.
  • the temperature difference deformation is to increase the axial force of one pile, and the axial force of the other pile is reduced.
  • the vertical joint force of the fork pile joints is roughly offset, and the vertical displacement caused by the joints is small.
  • the longitudinal direction of the high-pile wharf is a relatively flexible structure, and the influence of the temperature difference on the vertical deformation of the superstructure can be ignored.
  • the constraint condition for controlling the axial force of the temperature difference is mainly the problem of foundation deformation.
  • Hong Kong workers have no experience in this area.
  • the standard value of the load applied by the pile foundation is not more than 1/2 of the bearing capacity of the foundation, the remaining 1/2 is a safety reserve for the bearing capacity. It is recommended to limit the axial pressure (calculated larger than the actual value) for calculating the temperature difference. It does not exceed 1/2 of the bearing capacity of the foundation. In this range, the pile bearing capacity of the pile can be ignored regardless of the temperature difference. influences.
  • the vertical deformation of the superstructure caused by the temperature difference is also not considered in this range.
  • the design value of the equivalent temperature difference is determined according to Article 2.
  • the internal force partial coefficient generated by the temperature difference deformation is not specified in the port engineering specification. Considering the slow deformation of the temperature difference and the creep of the soil, the actual internal force generated by the temperature difference does not exceed the calculated internal force ( Especially soft soil), the hazard to the dock structure is a problem of durability. It can be tentatively set to a sub-factor of 1.0, which is considered as a dead load (quasi-permanent load).
  • pile diameter should be considered comprehensively including factors such as pile stability, pile spacing and transverse angle.
  • the longitudinal calculation is calculated according to the hinged condition of the pile top. It should also be calculated according to the condition of the pile top just connected. According to the bending moment of the pile top calculated, the range of the traditional hinge structure is allowed to be calculated. For foundation piles whose bending moment is greater than the bending strength of the pile body, a new type of hinge structure for reducing the bending moment of the pile top should be adopted.
  • the longitudinal beam and pile cap design should consider the internal force of the pile top and the internal force of the pile top when calculating the longitudinal deformation of the longitudinal horizontal force.
  • the frame with longitudinally loaded oblique piles in the middle section shall take into account the following effects of the horizontal pile forces caused by the longitudinal pile: 1
  • the horizontal direction of the beam is subjected to force and can be divided into: horizontal beam horizontal bending composite beam and lower beam branch
  • the cantilever is in the three aspects of the longitudinal beam and the upper beam as the three-sided constraint plate. Since the horizontal stiffness of the lower beam is large and the load is generally greater than the load of the upper beam as the force of the plate, the load factor of the beam can be removed safely by 1.0 and the load factor of the upper beam is 0.5.
  • the horizontal beam bending continuous beam calculation of the lower beam can be regarded as the elastic hinge support calculation reinforcement; the lower beam support cantilever on the longitudinal beam can be arranged near the longitudinal beam to satisfy the support reaction force of the cantilever bending Requirement;
  • the upper beam acts as the plate and its maximum bending moment is located at the joint of the upper and lower beams.
  • Vertical reinforcement can be arranged within 6 times of the upper beam width on each side of the pile to resist the bending moment of the upper beam as the plate. The bending reinforcement of the upper beam in the horizontal direction does not have to be reinforced (because the lower beam bears the horizontal force).
  • the lower beam horizontal shear stirrups, the upper and lower beams connect the stirrups, and the lower beam sides
  • the horizontal bending reinforcement and the cantilever bending reinforcement at the longitudinal beam are all determined by calculation.
  • the preliminary analysis shows that the amount of steel bars added by the beam against the longitudinally stressed diagonal piles is not much, and can meet the requirements within the range of normal reinforcement. 2
  • the vertical force of the beam shall take into account the vertical reaction force generated by the inclined pile under the horizontal force and participate in the load combination calculated by the frame.
  • the anti-pulling (or compression) bearing capacity of the friction piles during seismic verification does not have to take into account the pile axial force caused by the temperature difference, because The pile axial force caused by the temperature difference is not always a constant force, and has no effect on the ultimate bearing capacity of the pile.
  • Construction process Piling a horizontal and vertical clamping pile, pouring a pile cap or a lower beam ⁇ post-casting across the two sides to strengthen the whole pile. After demolition, the pouring belt is longitudinally piled up. The prefabricated beam is installed. The bottom support and the bottom formwork are poured. Post-casting with concrete, pouring, pouring concrete, forming a monolithic structure
  • the first post Before installing the prefabricated longitudinal beam, the first post should be reinforced across the adjacent span to strengthen the whole pile, which can be added on the basis of the existing transverse pile 083 and the longitudinal pile 082, with the method of adding the cross-pile 081; After the completion of the reinforcement of the overall pile, the longitudinal pile 082 of the back span is removed; as shown in Fig. 26.
  • the non-post-casting beam should be placed first, and then the longitudinal beam should be placed after the vertical beam.
  • the longitudinal beam is symmetrically placed on the other side, so the joint force is basically balanced, and it is not necessary to set the backing support.
  • the sliding cushion can be treated by oiling and other methods.
  • the purpose of the sliding cushion is to further eliminate the influence of temperature difference deformation on the structure (Fig. 093 is cast concrete, 094 is longitudinal beam, 095 is pile cap or lower beam, and 096 is pile support).
  • Pre-fabricated stringers should be installed after more than 2 months of age. It is advisable to choose a season that is 10° lower than the annual average temperature. After pouring, the concrete is poured across the concrete.
  • the construction process of the long section wharf is basically the same as that of the conventional wharf.
  • the post-draining cross-over treatment is also very simple, and the design and construction are feasible.
  • the long-segment structure expansion joint has a large amount of expansion and deformation, which can reach more than 10cm. It is necessary to study the connection structure between the track machinery and other flow machinery smooth transition joints.
  • the long section wharf has a large amount of expansion and contraction, if the track is broken at the expansion joint, the maximum gap of the track will not be smaller than the expansion and contraction amount of the temperature seam. Since the expansion amount of the long section pier is large, the gap of the expansion joint is generally 5 ⁇ 10cm, can not meet the requirement that the track allows the gap to be 2cm, so the track adopting the disconnected form cannot be applied to the long section pier. If the track is longitudinally welded, the relative temperature difference between the day and night of the track and the concrete section of the wharf structure is large, and the relative expansion and contraction of the track is also large. The track at the expansion joint of the long section pier is not affected by the two ends.
  • the balance is easy to produce longitudinal displacement, and it is easy for one end of the track to reach the blocking structure to generate a large reaction force; during the relative displacement of the longitudinal direction of the track, the frictional force generated by the track friction force, the static weight of the door machine, etc. Produces ambiguous longitudinal forces.
  • the new form of orbital connection proposed in this paper can overcome the above shortcomings.
  • the schematic diagram of the installation of the temperature seam track proposed by the present invention is shown in Fig. 3.
  • the schematic diagram of the working principle of the track is shown in Fig. 4, and the schematic diagram of the track connection is shown in Fig. 5.
  • the rail connection structure includes a main rail (11) spanning the expansion joint, a rail (16), a connecting piece (12), a bottom plate (13), a vertical plate (14), a pressure plate (15), and a top plate (18).
  • the main rail is connected to the attached rail and the attached rail by a connecting piece; the bottom plate, the vertical plate and the top plate are welded; the pressing plate is fixed to the vertical plate by bolts.
  • the track can slide longitudinally along the area defined by the bottom plate, the vertical plate, and the pressure plate.
  • the gap range at the track joint is controlled by the elongated hole (123) on the connecting piece (the maximum gap amount can be controlled to 20 mm).
  • the position adjustment of the bottom plate and the pre-embedded bolt (132) is achieved by a wide half opening (131) of the bottom plate.
  • the main track and the attached track are both "work" type structure. See Figure 6 to Figure 11.
  • the main track (11) spans the expansion joint (19).
  • the length should be 60 ⁇ 80cm. It has a certain length and is suitable for adapting to a small amount of the two platforms. dislocation.
  • a fixed length of the original track is left at both ends of the welded steel plate for rest and expansion on the bottom plate (13).
  • the length of the attached track is about 20cm.
  • An elongated hole (123) is formed at each end of the connecting piece (12). See Fig. 9.
  • the main rail and the attached rail and the attached rail are connected to each other in series by a connecting piece.
  • the connection is made by bolts passing through the circular hole (1113) and the elongated hole (123).
  • the bolt has a longitudinal gap after being connected with the elongated hole (123) of the connecting piece, and the longitudinal gap is used for controlling the amount of the expansion and contraction gap between the tracks.
  • the main rail and the rail top surface (111) of the attached rail are disposed at a main oblique angle (1111) of about 30° with respect to the longitudinal axis (for the sake of simplicity, the rail is not illustrated with an oblique angle);
  • the acute angle end of the main oblique angle (1111) is provided with a chamfer (1112), the chamfer is about 5° with the longitudinal axis, and the cutting depth is about 4 to 5 mm.
  • the steel plate (17) can be welded under the bottom surface (112) of the main rail to enhance the bending resistance of the main rail.
  • the number of attached rails is determined according to the maximum amount of expansion and contraction of the expansion joint.
  • the main rail can be welded under the rail bottom surface (112) with steel plates (17) as shown in Figures 7 ⁇ 8 to enhance the bending resistance of the track.
  • the length of each end of the main rail used to rest on the bottom plate is desirable. Error + minimum shelf length + floor reduction due to the inclined top surface.”
  • the through hole 123 height, the through hole 1113 and the connecting bolt diameter should be about 20mm. After the nut is installed, it can be fixed by electric welding to prevent loosening.
  • the bottom plate (13) is provided with two vertical plates (14), the inside of which is provided with a pressure plate (15), and the vertical plate and the pressure plate are provided with circular holes (19) and 20), the vertical plate and the pressure plate are fixed by bolts through the circular holes (19) and (20), so that the main track and the attached rail are restricted to slide in the area surrounded by the bottom plate, the vertical plate and the pressure plate, and the track and the restricted area are The gap is controlled between 1 and 2 mm.
  • a top plate (18) is welded to the vertical plate (14) to prevent the pressure plate (15) from jumping out and forming a wharf surface.
  • the bottom plate (13) is provided with a half opening (131).
  • the position of the floor can be adjusted on the pre-embedded bolt (132), which is pre-buried in the cast-in-place concrete prior to laying the track.
  • the spacing of the bottom plates on both sides of the expansion joint shall be determined by calculation based on the maximum amount of gap and the temperature at the time of installation. After use, observation should be made, and problems should be disassembled and adjusted in time.
  • the connecting structure is easy to process, convenient to install and maintain, and can meet the requirements of the expansion joint of the long section wharf.
  • the wheel crosses the gap and is seamless and continuous transition in the cross section.
  • the door machine works smoothly and can adapt to the use of the two sections of the platform. A small amount of spatial misalignment has occurred.
  • the expansion joint track does not transmit longitudinal forces at all.
  • the long-segment wharf expansion joint has a large amount of expansion and contraction (generally 5 ⁇ 20cm).
  • the traditional dock expansion joint form can not meet the requirements of smooth running of the traffic flow.
  • the bridge has many expansion joint forms (such as tooth-shaped expansion joints, etc.). Transplanted. However, the form of the expansion joint of the bridge is more complicated. This paper provides a simple expansion joint form, which can be used for terminals with low traffic volume and low speed.
  • the lower steel plate is attached to the concrete surface.
  • the maximum length of the upper steel plate can be increased by about 40cm, and the thickness can be determined by calculation, but it should not be less than 20mm.
  • the diameter of the round hole of the upper steel plate should not be less than 25mm, and the diameter of the upper nut position should be larger than the diameter of the nut. See the upper steel plate of Figure 16. Amplify the hole (203) so that the installed nut is lower than the upper steel plate surface.
  • the lower steel plate (202) should be installed slightly inclined (see Figure 15), and the height difference between the two ends can be about twice the thickness of the steel plate (201).
  • the sliding end of the upper steel plate resting on the lower steel plate should be cut into a small oblique angle (204) of about 6 ⁇ 8°, so that the flow machine can be beaten less when it passes through the expansion joint.
  • Installation requires that the upper steel plate is in a horizontal state when the expansion and contraction amount is about half.
  • the installation position of the upper and lower steel plates and the pre-embedded bolts should be determined by the temperature calculation during construction.
  • the expansion joint is not blocked by the pier shreds, it is reliable in operation, easy to maintain, and easy to disassemble.
  • the dock expansion joint has a construction gap next to the connecting rail (400), which can be covered with a long steel plate. When the track needs to be adjusted, the covered steel plate can be opened for track maintenance.

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Description

离岸高桩码头长分段结构 技术领域
本发明涉及港口工程领域， 具体涉及高桩码头结构。 背景技术
从上世纪 80年代开始、 特别是 90年代以来， 随着世界航运市场船舶大型化的趋 势， 我国建设投产了一批离岸深水高桩码头， 包括大型集装箱码头、 10〜45万吨级矿 石和原油码头等。 随着码头向离岸式、深水化、大型化方向发展， 码头前沿水深已从过 去一般小于 12m、 结构的排架间距 5〜7m、 桩基普遍采用方桩的传统结构形式， 提高到 目前前沿水深可达 20〜27m、排架间距 7〜12m， 桩基可采用方桩、大管桩、钢管桩、钢 板桩、格型钢板桩、组合桩等多样结构形式。建港条件也从过去沿江、海岸水深和风浪 不大的良好环境发展到离岸、水深浪大的恶劣环境。根据港口工程结构的发展趋势， 我 国从 80年代开始就陆续进行了深水筑港技术的研究， 目前高桩码头结构已出现了许多 新的形式， 如全直桩结构、 大直径嵌岩桩结构、 带消浪设施结构、 导管架结构、双排大 管桩结构、双横梁结构、架空直立式结构、轨道梁下设置桩结构、悬链线拱式纵梁结构 等， 总体上是不断向着码头大型化、 长桩大跨、 大型构件、 结构简单的方向发展。我国 幅员广大、地质条件复杂、港口工程建设规模大、 实践经验丰富， 经过工程技术人员的 60 多年实践经验总结和创新发展， 以及多年引进和吸收国的外先进经验， 目前我国高 桩码头结构的研究、设计及施工等方面巳达到了国际较高的水平，高桩码头结构形式尤 其是桩基形式呈多样化发展， 无论大小码头、尤其是外海深水码头， 高桩码头结构形式 都得到了最普遍的应用，从深厚软土地基到浅覆盖层岩石地基等多种复杂地质条件下都 能找到高桩码头成功应用的实例。高桩码头结构的设计理论及标准体系也日趋成熟， 已 达到国际先进水平， 正逐步走向完备。
伹是， 目前虽然已有不少高桩码头的创新结构形式， 然而对高桩码头分段长度的 问题仍未作过深入的研究， 设计基本上还是按规范取值。 《高桩码头设计与施工规范》 规定对装配式高桩码头分段长度取 60~70m， 对大跨度结构而言， 上述常规分段长度所 允许的排架跨数较少， 如采用 12m跨度在每个分段内只允许 5跨。 我们知道分段内的排 架跨数越少、 排架所分担的水平力系数就越大， 如当分段跨数为 5跨时最大排架分配系 数为 0.524，而当分段跨数为 10跨时最大排架分配系数为 0.310， 即分段跨数 5跨比 10跨的
1
确 认 本 基桩分配水平力增大了 69%。 当水平力成为控制因素时， 常规分段长度的跨数制约往往 就成为消弱甚至抵消大跨度码头优势的因素之一。
对深水大型码头， 由于船舶产生的水平力大、 常规分段长度内排架的水平力分配 系数大、 混凝土桩 （含大管桩、 PHC桩等， 下同）在深水或浪大区所允许的斜度较小， 因此经常无法采用混凝土桩抵抗码头水平力而被迫采用钢管桩，从而大大增加码头的建 造成本和维护费用。
结构分段长度的控制具有两方面目的： 一是消除差异沉降对结构的影响； 二是消 除温差等伸缩变形对结构的影响；通常分段缝是沉降缝与伸缩缝的合并缝，对高桩码头 而言， 由于上部结构的纵梁高度较低、一般采用预制安装施工， 纵向刚度相对较小、 结 构的塑性调整能力也较好， 因此结构适应纵向差异沉降的能力较强。在纵向地质变化比 较缓慢的情况下，结构自身一般能适应纵向不均匀缓慢变化的差异沉降，通常只要求在 荷载差异大、地质变化较大或结构断层等处设置沉降缝。 当纵向地质变化较平缓时， 高 桩码头的分段长度通常是受纵向伸缩变形控制，限制码头分段长度主要是为了控制混凝 土收缩及气象温差产生的纵向伸缩变位及纵向内力，避免桩基和结构发生损坏或影响正 常使用。
规范规定的分段长度只是对码头结构的适应能力作简化处理， 即在该分段长度内 可不考虑温差变形及混凝土收缩变形对结构的影响， 其不足之处在于：
(1)没有考虑结构对温差及收缩变形的适应性。 经分析认为： 桩的泥上高度、 桩身 刚度、 强度及塑性、 地质条件、 桩基布置、桩顶连接、平台结构及施工方案等对分段长 度影响很大， 可使分段长度相差数倍， 应是划分码头分段长度的主要考虑因素。
(2)不能充分利用码头分段长度的潜力以增加码头分段排架数量， 使基桩承担的水 平力减小、 以利于混凝土桩的应用。
(3)有些码头泊位如充分利用分段长度潜力时也许不用分段， 但采用简化的分段长 度控制值时却必须分段， 增加了伸缩缝以及装卸工艺跨越伸缩缝的处理。
目前尚未査询到有关确定高桩码头分段长度计算方法的文献， 在实践中高桩码头 实际分段长度已有突破 70m的情况， 如宁波港北仑港区国际集装箱码头工程的分段长度 达 95m， 但是目前对长分段结构设计还没有作理论上的分析与总结， 没有提出相应的计 算方法与设计理论， 己出现过因不恰当地增加分段长度而造成桩基纵向开裂的情况。
对离岸深水码头， 桩的泥上高度大、 结构纵向适应混凝土收缩与温差变形的能力 可远好于传统的岸坡码头，分段长度应该允许视具体情况适当增加。 目前与高桩码头类 似的桩柱基础梁桥结构，其伸缩缝分段长度已远大于现有的高桩码头分段长度，离岸水 深码头采用远大于传统分段长度是可行的。经过分析可知，对工程条件较好的离岸深水 码头， 如结构布置合理， 其分段长度可大于 200m以上。
采用长分段码头结构具有以下直接的优点：
(1)码头的抵抗横向水平力的能力大、 刚度大、 整体性好；
(2)分段内排架联系的超静定次数多、 码头整体抵抗横向水平力的富余强度大；
(3)基桩分担的水平力减小， 有利于采用混凝土桩代替钢管桩， 长分段结构一般可 采用混凝土桩， 当全部采用混凝土桩不足以抵抗水平力时，可仅在分段两端附近将叉桩 采用钢管桩代替， 总体上采用的钢管桩比例仍然较低；
(4)对工程条件较好的单一泊位码头通常可不分段， 有利于码头上的工艺布置；
(5)有利于大跨度结构形式的应用。
此外， 由于长分段结构的分段长度远大于传统码头， 可针对长分段结构特点提出 优化桩基布置与结构设置方案，可在此基础上提出新的高桩码头结构形式，达到进一步 的技术创新与降低造价等目的。 本发明对长分段结构采用进一步优化技术如下：
(1)距温差纵向位移零线 25m以外的叉桩采用小横向夹角布置，以减小纵向伸缩产 生的叉桩轴力。
(2)距温差纵向位移零线 25m以内的叉桩沿纵向受力布置，必要时还可将一部分承 载力有富余的直桩也布置成纵向受力斜桩， 以提高分段的纵向抗力。
(3)分段两端附近的叉桩可采用钢管桩， 其余中间区域的叉桩以及全部直桩采用砼 管桩， 以发挥桩基的整体作用。
(4)为减少桩顶弯矩， 增加分段长度以减小桩承受的水平力， 采用桩顶铰接形式， 提出适用于高桩码头长分段结构的铰接技术。
(5)长分段两边缘第一跨排架间距可小于内跨间距， 以减小纵梁、 横梁及桩的设计 控制内力， 进一步降低造价。
(6)设置混凝土后浇跨， 可消除大部分混凝土收缩及气象温差对结构的影响， 还可 减轻结构自重产生的差异沉降。
随着离岸深水码头建设的发展， 长分段结构具有很好的应用前景。 发明内容
离岸高桩码头长分段结构， 分段长度不小于 120m; 位于温差纵向 '位移零线（指码 头发生温差变形时，在平台中间附近的无纵向位移的横向线，可按说明书第 12页公式 3-15计算） 25m以外的叉桩均采用小横向夹角布置； 位于温差纵向位移零线 25m以内 的叉桩沿纵向受力布置； 桩基的桩顶采用铰接形式； 分段两边缘第一跨排架间距小于 内跨排架间距； 在码头伸缩缝处采用多小段间隙不超过 20mm的轨道连接结构。
所述的长分段结构， 其分段长度不小于 120m， 工程条件好时可达 200m以上， 远 大于常规高桩码头的分段长度。分段长度根据具体码头工程的桩径、泥上长度、地基条 件、桩顶连接、桩身强度和刚度、 桩基整体布置、 纵梁安装后混凝土的收缩率、 施工安 装情况、 年气象温差， 平台水平刚度， 排架间距和排架水平刚度等情况确定。
所述的长分段结构， 距离距温差纵向位移零线 25m以外（如图 1的 B区） 的叉桩 均采用小横向夹角布置 (如图 1桩 3)， 夹角宜根据桩基布置及打桩偏差情况通过计算后 确定。打桩偏差应考虑： 桩顶水平面偏位、 方位角偏差、仰俯角偏差、 左右摆动角偏差 等， 在确保不会发生碰桩的前提下， 宜尽量减小叉桩的横向夹角， 横向夹角一般可取 10〜18°。 对温差变形产生较大轴力的基桩， 可采取以下措施进一步减小叉桩的横向夹 角： ①将可能碰桩的相邻直桩 （如图 1桩 4) 改为斜度不大于 20: 1的反向纵向斜桩； ②斜桩桩顶与可能碰桩的相邻直桩桩顶采用偏离排架轴线约 10cm左右错幵布置（如图 1中 3桩顶偏右 10cm, 4桩顶偏左 10cm)。当全部采用混凝土桩难以满足码头抗横向水 平力要求时， 可将分段两边缘若干排架的叉桩换成倾斜度较大的钢管桩 （如图 1 的 F 区桩 5)， 钢管桩的尺寸及布置区域由计算确定。
所述的长分段结构， 距离温差纵向位移零线 25m以内 （如图 1的 A区） 的叉桩沿 纵向受力布置 （如图 1 中的桩 2)， 必要时还可将一部分承载力有富余的直桩也布置成 纵向受力斜桩。 纵向受力桩的纵向夹角一般小于 45°， 采用混凝土桩， 倾斜度可小于位 于温差纵向位移零线 25m以外的混凝土叉桩， 布置纵向受力叉桩的最小桩数及倾斜度 由码头分段所承受的纵向水平力及抗震要求确定。
所述的长分段结构， 桩顶铰接形式可分区段采用不同的连接结构： 对桩顶弯矩小 于桩身强度的位于中间区段基桩，桩顶铰接可采用常规做法；而对桩顶弯矩可能大于桩 身强度的位于分段边缘区域的基桩，桩顶铰接可采用本说明书提出的降低桩顶弯矩的铰 接结构。
所述的分段两边缘第一跨排架间距 （图 1间距 d) 小于内跨间距 （图 1间距 c), 以减小纵梁、横梁及桩的设计控制内力， 可按照边缘排架的基桩、纵梁、横梁的控制内 力接近中间排架控制内力的要求， 确定第一跨排架间距。 所述的长分段结构， 纵梁施工安装前每隔 40〜60米应拆除一跨纵向夹桩， 以完全 释放纵向夹桩力、 并在此设置后浇跨， 以降低长分段码头纵向混凝土伸缩产生的内力。
所述的码头伸縮缝处的轨道衔接可采用本说明书提出的轨道连接结构。
本发明成功解决了码头长分段结构应用的技术问题，长分段结构适用于地质纵向较 均匀、 采用摩擦桩的深水离岸高桩码头。 附图说明
图 1为本发明所涉及的长分段码头桩基结构布置示意图；
图 2a为本发明所涉及的降低桩顶弯矩铰接桩立面示意图；
图 2b为本发明所涉及的降低桩顶弯矩铰接桩平面示意图；
图 2c为本发明所涉及的降低桩顶弯矩铰接桩倾斜连接图；
图 3为本发明所涉及的长分段码头温度缝轨道安装示意图；
图 4为本发明所涉及的长分段码头轨道平面连接缝的俯视图；
图 5为本发明所涉及的长分段码头轨道平面连接缝的主视图；
图 6为本发明所涉及的长分段码头主轨道的俯视图；
图 7为本发明所涉及的长分段码头主轨道的左视图；
图 8为本发明所涉及的长分段码头主轨道的主视图；
图 9为本发明所涉及的长分段码头连接片的示意图；
图 10为本发明所涉及的长分段码头附轨道的左视图；
图 11为本发明所涉及的长分段码头附轨道的主视图；
图 12为本发明所涉及的长分段码头压板的示意图；
图 13为本发明所涉及的长分段码头底板、 立板的示意图；
图 14为本发明所涉及的伸缩缝结构安装平面图；
图 15为本发明所涉及的伸缩缝结构立面装配示意图；
图 16为本发明所涉及的伸缩缝结构上钢板的示意图；
图 17为中国沿海各地一月的平均气温图；
图 18为中国沿海各地七月的平均气温图；
图 19为钢筋混凝土、 混凝土和石砌体矩形截面杆件计算温度图解；
图 20为码头断面图；
图 21为横梁截面示意图； 图 22为纵梁截面示意图；
图 23为轨道梁截面示意图；
图 24为中板斜坡顶平台宽度计算图；
图 25为锚固钢筋及抗剪板计算简图；
图 26为后浇跨两边加强整体夹桩及拆除后浇跨纵向夹桩图;
图 27为后浇跨纵立面示意图。 具体实施方式
为了使本发明实现的技术手段、创作特征、达成目的与功效易于明白了解， 下面结 合具体图示， 进一步阐述本发明。
1本发明解决了髙桩码头长分段结构的以下关键技术
离岸深水长分段结构与常规结构相比具有明显的不同， 在桩基布置、 桩顶连接、 排架布置、施工工艺、技术要求及计算方法等方面都有自身的特点。长分段结构是一种 创新的结构型式， 需要解决以下关键技术问题：
(1) 由于分段长度远大于常规码头分段长度， 结构纵向受气象温差与混凝土收缩等 因素产生的内力不可忽视， 因此需要考虑长分段码头结构的混凝土收缩、气象温差变化 的设计取值问题。
(2) 由于目前尚未査询到高桩码头在温差与荷载作用下既简单又能满足设计要求 的纵向计算方法， 因此需要提出在温差与荷载作用下简便合理的纵向计算方法。
(3) 船舶作用力在各排架上的分配问题是解决码头结构简化为排架计算的前提条 件之一，目前在高桩码头设计中，横向分力在各排架的分配是按弹性支承刚性梁法计算。 但是对长分段码头而言， 由于分段长度远大于常规值，其水平力的分配计算问题是否仍 可采用弹性支承刚性梁法还需要论证，需要研究在什么条件下可采用刚性梁法，在什么 条件下应采用弹性梁法， 以及如何计算等问题。
(4) 长分段结构位于分段边缘附近的桩顶受混凝土收缩与气象温度变化等作用产 生的纵向位移较大，如按传统方法在两端附近布置纵向受力斜桩来增强纵向抗力，则斜 桩会产生很大的温差内力，桩基如何布置才能既不产生较大的温差涨缩桩力，又能满足 码头的纵横向水平抗力要求， 并能发挥桩基的整体最优效果等是需要解决的问题。
(5)桩顶采用刚接形式主要是为了提高码头水平抗力及增强水平刚度。 但是由于， 一方面采用刚接的桩基由混凝土收缩与气象温度变化产生的内力也大；二方面离岸深水 码头在风浪较大条件下也很难做到桩顶刚接，而铰接模式是允许连接点活动转动，能适 应在风浪较大环境下施工难以达到刚接的要求； 三方面离岸深水码头桩基泥上长度较 大、一般有布置叉桩， 桩顶刚接所提高水平抗力的作用减小。 因此有必要研究利用桩顶 铰接使分段长度增大、基桩承受的水平力减小，从而补偿桩顶刚接所提高水平抗力及刚 度的方案是否更加合理。
(6)铰接桩按规范及通常的做法是将桩顶埋入桩帽或横梁 5〜10cm, 这种铰接处理 方法施工方便， 但它是介于铰接与刚接之间的连接方法， 在长分段结构中， 位于分段中 间部分（如在传统的 70m范围内）采用这种连接是没有问题的， 但是对于按刚接计算时 桩顶弯矩大于桩身强度的位于分段两边缘区域的基桩，采用传统铰接方式仍有可能会造 成桩顶开裂损坏，有必要研究桩顶铰接创新技术，使桩顶转角活动量大、传递弯矩较小、 能适应长分段码头的桩顶铰接要求。
(7)对于采用等间距排架布置的码头而言， 通常边缘 1〜2排架结构的内力一般大 些，中间排架的内力小些。传统码头多采用等间距排架布置，那是因为中间排架数量少， 若采用不同间距的排架布置，其减少的工程量与增加的施工难度相比并没多少优势。而 长分段码头中间排架数量众多，有必要通过技术经济比较分析边缘排架间距减小所增加 的施工难度与减小大量排架构件的设计内力降低的工程量相比是否值得。
(8)长分段码头的混凝土收缩与气象温差变化对结构纵向内力影响较大， 需研究长 分段结构的施工工艺及过程控制方法， 以降低长分段码头温差伸缩对结构的影响。
(9)需要根据长分段码头结构受力特点， 研究设计计算方法、 结构与构件设计与施 工要点。
00)长分段结构伸缩缝的伸缩变形量较大， 需要研究轨道机械与其它流动机械平稳 过渡伸缩缝的结构。
2 高桩码头混凝土收缩及气象温度变化设计值的确定
在混凝土收缩与气象温差等作用下，长分段码头会产生较大的纵向伸缩变位及纵向 内力， 由于高桩码头的分段长度通常是受纵向伸缩变形控制， 因此确定混凝土收缩与气 象温差的设计值是设计控制分段长度的重要参数。
离岸高桩码头一般采用整体装配形式， 产生纵向变形的因素有： 混凝土预制纵梁 和预制面板安装后的剩余收缩变形、现浇面板收缩产生的变形、预应力构件的徐变， 以 及年气象温度变形等。
预制纵梁和预制面板安装后混凝土剩余收缩变形的影响因素很多， 涉及到水泥品 种、砂石料、 水灰比、 添加剂、 养护条件、 养护天数、 预置期及预置期的温度等， 理论 计算与实测值的离散性也较大。在估计收縮终值时，在我国公路桥梁规范中计入了受荷 时混凝土龄期对收缩变形终值的影响。
根据桥梁工程的设计经验， 混凝土收缩应变可近似按下式计算： y = 20 x l0—5 x ， 预置 2个月后安装取 β=0.45， 预置 5个月后安装取 β=0.3。 码头设计如考虑按预置 2个月后 安装， 可取收缩应变 = 20 x 10— 5 X 0.45 = 9 x 10— 5， 由于混凝土温度线涨系数为 10- 5 /°C， 因此收缩应变等效于降温 9'C。
预应力徐变的应变公式可近似釆用： γ = 2Ασρ Ι Ε β，式中 0^是混凝土平均预 应力， 是混凝土弹性模量， 意义同上， 可取 0.35。对长分段码头而言， 只有预应力 对码头整个横截面产生的平均徐变，才会对码头的纵向伸缩产生整体影响，而纵梁的预 应力相对于码头整个横截面的平均应力很小， 故可不考虑预应力产生的徐变影响。
《铁路桥涵设计基本规定》（TB10002.1-2005 )混凝土收缩影响： 对于整体浇筑的 混凝土结构等效于降低温度 20°C ; 对于整体浇筑的钢筋混凝土结构等效于降低温度 15°C ; 对于装配式钢筋混凝土结构等效于降低温度 5〜10°C。
码头面板多采用叠合板， 对于叠合板情况， 混凝土现浇面板收缩量较大， 但现浇 面板收缩时会受到预制纵梁和预制面板的约束， 由于混凝土抗压强度远比受拉强度高， 如 C30#混凝土抗拉标准值为 2.00MPa， 抗压标准值为 20.00MPa， 弹性模量为 30000MPa， 当现浇面板收缩受到预制梁板的约束相当于温差 6Ό时， 温差产生的应力已达到抗拉标 准值 2.00MPa， 等效温差大于 6.7'C就会产生许多裂缝， 使现浇面板收缩力大量消散。 由 于码头设计尚无经验及测量数据，可暂偏安全地假定全部现浇面板的收缩力都得到充分 发挥， 并偏安全地按现浇截面占面板与预制纵梁面积之和的 1/2计算， 则平台截面的综 合纵向收缩应变等效于降温 15.7*l/2+9*l/2=12.4°C。
综合以上的分析： 预制构件安装后混凝土的剩余收缩变形及预应力徐变变形等可 按等效降温 12.4°C考虑， 考虑到目前港口工程的设计经验与实测数据不足， 可适当增加 变异偏差的影响，但不宜超过按整体浇筑的钢筋混凝土结构等效降低温度 15°C，暂可偏 安全地取等效降温范围下限为 5°C、 上限为 15°C， 按不利情况计算。
混凝土结构气象温差的设计值应考虑年最高与最低的月平均温度以及梁板厚度与 热导系数等。
中国各地冬夏的月平均温度不同， 北方温差大、 南方温差小， 气象温差可取年最 低月份与最高月份的月平均温差。 根据《铁路桥涵设计基本规定》（TB10002.1-2005 ), 沿海各地一月与七月的平均气温见图 17与图 18。
由以上两图可知：广州月平均气温最低 13°C、最高 28°C ;上海月平均气温最低 3'C、 最高 28Ό ; 天津月平均气温最低 -5°C、 最高 26°C。
《铁路桥涵设计基本规定》（TB10002.1-2005 )钢筋混凝土矩形截面计算温度图解 见图 19。
从图中可知， 截面尺寸越大， 计算温差取值越小。 高桩码头面板与纵梁两面露开 的厚度大部分小于 0.8m， 由图查得上海地区气温最低 3 'C时取 3 °C、 气温最高 28°C时取 30°C。
以下将混凝土收缩等效降温与年气象温差统一称为计算温差。
综上所述， 高桩码头结构纵向计算时， 混凝土收缩的等效降温温差可取 5〜15°C， 按不利情况取值； 上海地区气象温度变化计算值可取最低 3 °C、 最高 30°C。 混凝土收缩 与气象温度变化的计算温差可按不利情况组合考虑。
3码头结构纵向内力计算方法
现行高桩码头规范没有明确规定纵向力及温差对结构的内力影响如何计算，在设计 实践中通常采用以下两种方法：①假设纵向力由专门设置的纵向叉桩承担；②采用空间 计算方法计算纵向力的影响。
采用假设纵向力由专门设置的纵向叉桩承担的方法计算简便，但没有考虑到大量的 直桩与横向叉桩参与抵抗纵向水平力的作用，也没有考虑伸缩缝受力闭合后相邻分段的 共同工作，这种方法过于保守，一般适合于采用采用简单措施增加码头纵向水平抗力的 计算。
采用空间计算方法计算纵向力的影响又过于复杂， 实际上没有必要， 毕竟纵向水平 力及温差对上部结构产生的内力相对不大。
纵向计算主要是确定基桩的内力， 而上部结构内力不必计算得很精确， 只要根据基 桩内力推算即可。
结构纵向计算的简化方法， 要求考虑桩顶连接情况、 桩泥上高度、 桩身柔性、 桩 基布置等因素的影响。嵌固点法对荷载作用下计算的内力精度较高，而对位移作用下计 算的内力误差较大， 计算位移产生的桩弯矩不宜采用嵌固点法， 统一计算公式起见， 计 算荷载及位移产生的桩内力均釆用精度相对较高的 m法。
温差与纵向荷载作用下结构的内力与变形计算方法， 可作为设计确定分段长度的 依据。 3.1计算基本假定
根据结构受力特性与结构力学基本理论等， 结构纵向内力设计计算作了以下假定：
(1)上部结构的混凝土收縮与气象温差伸缩将带动桩顶产生水平变位， 桩顶的水平 变位将使基桩产生内力。考虑到码头平台平面变形刚度远大于基桩桩顶的水平刚度，上 部结构的混凝土收缩与气象温差伸缩在平面上的变形可近似认为是不受约束的。该假定 符合结构力学基本原理。
(2)基桩的桩顶连接分为刚接和铰接两种形式。考虑到刚接桩顶转角刚度一般远小 于纵梁体系的转角刚度，故可近似假定刚接桩顶在混凝土收缩、气象温差伸缩及纵向荷 载作用下桩顶不产生转角。由于不考虑桩顶转角时计算的桩顶弯矩值最大， 因此这一假 定对计算桩顶内力也是偏安全的。
(3)纵向计算不考虑结构平面扭转的影响。 长分段结构长宽比较大， 无论混凝土收 缩、气象温差伸缩、或码头上的纵向荷载作用， 产生的码头扭角都不大， 可以忽略平面 扭转所产生的内力。
(4)基桩受拉与受压的轴向刚度不变。 即叉桩在水平力作用下结点基本不产生竖向 位移，忽略桩顶结点在温差及水平力作用下产生的竖向位移。该假定使基桩计算的轴压 力一般偏大、轴拉力有时偏小， 总体上一般偏安全， 计算精度能满足在温差及水平力作 用下长分段结构的设计要求。
3.2桩顶单位水平位移产生的桩内力
以下先分析直桩内力， 然后以直桩成果为基础， 进一步分析斜桩内力。
(1)直桩内力计算
假定泥上高度为 h， 桩身抗弯刚度为 EI， 桩相对刚度系数为 T， 则可推导得到以下
① 当桩顶铰接时， 桩顶水平刚度为：
U =—— -3 —3 (3-1)
2.441Γ3 + 3342T2h + h3 /3 + l 5\h2T
② 当桩顶刚接时， 桩顶水平刚度为：
U = , 2 ―, i (3-2)
2.441Γ3 + \.62\T2(2h - w) + h3 /3 - wh2 /2 + \ 5\Th(h - w)
1.621Γ2 + 1.7517¾ + /z2 /2
¾T : w = (3-3)
/Ι + 1.751Γ 、 ' 设桩顶水平位移为 ξ， 贝 iJ:
桩顶剪力： Qt=U (3-4)
桩顶弯矩： 对铰接 Mt=0， 对刚接 Mt=Qtxw (3-5)
桩泥面处剪力： Qs=Qt (3-6)
桩泥面弯矩： Ms=Qtxh-M (3-7)
泥下最大弯矩的相对深度 λ=ζ/Τ， （式中 ζ为泥下深度） 可近似按下式计算：
λ 2.88 xTxQs+ 0.165 xMs)/(2.18xTxQs + Ms) (3-8)
泥下最大弯矩可近似按下式计算：
Μλ-(-0.039+ 1.23λ—0.46λ2)χΤχ(¾+(1 +0.07λ— 0.21λ2)χΜ8 (3-9) 计算示例： 假设 PHC直桩混凝土标号为 C80， 桩径 1.2m， 壁厚 0.145m， 泥上高度为 h=10m , 地基 m=10000kN/m4， 极限承载力 Qud=15000kN， 桩顶的轴向反力系数按 k = - ~~ l— ~确定。 （桩身 A=0.481m3， 1=0.0713m4 , E取 39000000kPa， 相对刚度 h 1
T=2.587m。）， 当桩顶水平位移为 ξ=10πιιη时， 内力计算结果如下：
桩顶铰接时， 由（3-1)式得 U= 2657kN/m , 由（3-4)〜（3-7)式得桩顶剪力 Qt=2642*0.01=26.4kN、 桩顶弯矩 Mt=0； 泥面剪力 Qs=26.4kN、 泥面弯矩 Ms=26.4* 10=264kN.m; 按 (3-8)、 （3-9)式得泥下弯矩 Μλ=2921ίΝ.ιη。
桩顶刚接时， 由 (3-2)、 （3-3)式得 w=7.305m， U=10295kN/m, 由 (3-4)〜(3-7)式得桩 顶剪力 Qt=10295*0.01=102.9kN、 桩顶弯矩 Mt=7.305*102.9=752kN.m ; 泥面剪力： Qs=102.9kN, 泥面弯矩1^=2771^.1^ 按 (3-4)、 （3-5)式得泥下弯矩 Μλ=4341ίΝ.ιη。
(2)斜桩内力计算
假定斜桩与竖直线的夹角为 α、纵向偏角为 0 y。设桩单元轴向坐标为 ξ、
Figure imgf000013_0001
时， 单元侧向坐标 η与横向整体 Y坐标重合、单元侧向坐标 ζ与纵向整体坐标 X相反。 当 桩顶
Figure imgf000013_0002
式中 、 φ 分别为单元轴线与 X、 Y、 Ζ轴的夹角， t为单元的自转角， S为 单元轴线在 XOY面上的投影长度。 将 cos = sina . cos；^、 cos^ = sin a . sin ^、 cos = cos a、 S = sin a， X= Δ、 Y=Z=0代入上式可得桩单元坐标位移为：
= sin (a) xcos(ey)x A (3-10)
η= -sin( β y)x Δ (3-11)
ζ =-cos(a) xcos( β y)x Δ (3-12)
假定桩顶的轴向反力系数为 Κ， 桩的轴力可按下式计算：
Figure imgf000014_0001
桩单元侧向刚度 U可按公式 (3-1)〜(3-3)式计算，但需将公式中的 h采用桩泥上长度 L 代替； 桩单元的弯矩与剪力可根据单元侧向位移 η及 4按公式 (3-4)〜(3-7)式计算。
斜桩单元的纵向整体刚度为：
V=K xsin2(a) xcos2( β Z)+Ux[sin2( β ζ)+ cos2(a)xcos 2( β ζ)] (3-14) 计算示例： 假设 PHC桩， 纵向叉桩斜度 4: 1， 即 a=atan(l/4)=14.04°、 β y=0°， 其它条 件同上， 桩顶的轴向反力系数近似取 K = + /{UQQ ) = 95600 (kN/m) , 内力计 算如下：
单 元 轴 向 位 移 =10xsin(14.04°)=2.43mm , 单 元 侧 向 位 移 ζ =-10xcos(14.04°)=9.70mm;
桩轴力 N=956000x0.00243=2323kN。
当桩顶铰接时， 由（3-1)式得 U= 2657kM/m , 由（3-4)〜（3-7)式得桩顶 Qt=2642x0.097=25.6kN, 桩顶 Mt=0; 泥面 Qs=25.6kN、泥面 Ms=25.6kN.m; 由 (3-4)、 (3-5) 式得泥下最大 Μλ=283 kN.m。
当桩顶刚接时， 由 (3-3)、 （3-2)式得 w=7.305m， U=10295kM/m, 由 (3-4)〜(3-7)式得 桩顶 Qt=10295*.0097=99.9kN， 桩顶 Mt=7.305x99.9=730kN.m ; 泥面 Qs=99.9kN、 泥面 Ms=269kN.m; 由 (3-4)、 （3-5)式得泥下最大 Μλ=4211ίΝ.πι。
通过以上计算示例可知，桩顶水平变位对直桩与叉桩产生的弯矩相差不大，但叉桩 会产生轴力。
3.3温差产生桩顶位移的计算
(1)各桩顶由温差产生水平位移的主要影响因素有： ①温差纵向位移零线（温差纵 向位移零线是指码头发生温差变形时，在平台中间附近的无纵向位移的横向线）的距离 Y(m); ②年最低〜最高月平均气象温度 t,〜t2 V； ③混凝土综合收缩的等效降温范围 tcX 〜tc2。C; ④纵梁安装施工时调整后的气象温度 V。
(2)温差纵向变形位移零线的纵向坐标 可按下式确定： 。
Figure imgf000015_0001
式中： y,、 、 u [^分别是第 根直桩、 第_根斜桩的纵向坐标与水平刚度。
(3)桩顶产生的温差位移 (m)为：
ξ = μχΑίχΥ (3-16)
式中： μ ~~混凝土线涨系数， 取 10_V°C;
△t 计算温差 (°C) ， ¾ Δί = max{t2 -tg - icl ,tg -t, +tc2}, 其中左项大时以 是膨胀控制， 右项大时以是收缩控制；
Y ~~桩顶与温差纵向位移零线的纵向距离 (m)。
一般当处于年最高温度期间安装纵梁是最不利的。 如上海地区纵梁安装期间调整 后的温度为 30°C， 则最大膨胀温差 = t2 -tg -teI =30-30-5=-5°C， 最大收缩温差
At = tg -t, + /c2 =30-3+15=42°C, 以最大收缩温差 42 °C为控制。
当纵梁安装时期的气象温度处于 +t2 -te2)/2时，结构产生的温差内力最小， 此时最大膨胀与最大收缩温差相等， 上例 At=18.5'C。
如分段两边缘排架相距 200m， 分段是纵向对称情况， 则温差纵向位移零线位于中 轴线， 边缘排架桩顶距温差纵向位移零线 100m， 假定设计温差取 Δί=42Ό， 则桩顶最大 位移为：
^ = 10_5 42 100 =0.042m=42mm。
严格地说， 桩顶位移还与夹桩时的纵向夹桩联系梁的温度有关， 由于夹桩联系梁 截面小， 常用钢材， 短时的截面平均温度变幅大， 因此考虑夹桩时的联系梁温度影响是 比较复杂的。但可以采用施工技术措施消除夹桩时联系梁温差变形的不利影响。采用的 施工措施如下：①当夹桩时如果气象温度很高，则宜采用泼水等方法降低纵向联系梁的 温度后再夹桩；②如果纵梁安装期间的温度低于夹桩时的温度，则在长分段码头安装纵 梁前， 可每隔 40〜60米将纵向夹桩联系梁松弛以释放夹桩产生的温差应力。
3.4纵向水平荷载作用下桩基的内力计算
在纵向水平力作用下，可近似将所有基桩的桩顶合成为一个水平刚度， 合成纵向水 平总刚度 J可按下式近似计算： J =∑Ui +∑VJ (3-17)
式中： 、 yj u、 ^分别是第 根直桩、 第 根斜桩的纵向坐标与水平刚度。 设码头纵向水平合力为 Η， 则码头产生的纵向水平位移 ξ为：
A = H /J (3-18)
得到码头纵向水平位移 Δ后， 各桩的内力就可按公式 (3-1)〜(3-13)计算了。
3.5纵梁、 桩帽或下横梁的内力
计算纵梁、 桩帽或下横梁的内力时， 可将桩顶内力作为外荷载处理。
当桩顶位于纵梁之间时， 可将桩顶反力仿照荷载按简支梁法分配于纵梁上。 由于温 差与纵向水平荷载产生的纵梁内力不大、不起控制作用， 因此产生的纵梁内力可近似计 算。假设桩顶反力对纵梁产生的弯矩为 Mz， 可近似按中间支座两侧纵梁弯矩取 Mz/2、 边缘支座内侧纵梁弯矩取 Mz确定。
长分段结构因温差产生的纵截面轴力有时较大、纵梁与面板设计时可以考虑。平台 横截面最大轴力发生于温差纵向位移零线位置， 全截面的最大轴力为： N =∑i/A +∑^A ' 其中 、 、 △、 分别是的第 /根直桩、 第 根斜桩的水平 刚度与纵向温差位移、注意只取温差纵向位移零线一侧的各桩水平力之和，各纵梁与面 板的轴力可按面积比例分担。
桩帽内力可根据桩顶反力由静力平衡法直接确定。
当采用无桩帽形式桩基沿下横梁布置时，在温差及水平荷载作用下斜桩桩顶反力对 横梁的作用可分解为竖直和水平两个方向。①对横梁的竖向作用计算，可将斜桩的竖向 反力作为水平荷载的附加竖向力作用于横向排架上，按横向排架计算内力并参与荷载作 用组合；②对横梁的水平向作用计算， 可将下横梁视为支承于纵梁结点上的连续梁， 支 座由纵梁向下悬臂工作的下横梁承担， 上横梁可视为是三边受约束的板。
下横梁水平抗弯内力可先按连续梁计算、然后根据经验调整； 其支座即纵梁下悬臂 工作的下横梁应配置连接纵梁的竖向钢筋以满足支座反力的悬臂抗弯要求，竖向钢筋分 布范围可取纵梁宽度加两边下横梁宽度的一半；桩顶反力对上下横梁连接处产生的弯矩 及拉力，应在桩每侧 3〜6倍上横梁宽度内布置竖向钢筋承担； 因为下横梁的水平刚度远 大于上横梁的水平刚度，因上横梁不必增强水平方向的抗弯配筋。下横梁水平抗剪箍筋、 上下横梁连接箍筋、下横梁两侧的水平抗弯钢筋以及纵梁下的悬臂抗弯钢筋均宜通过计 算确定。分析表明： 横梁抵抗纵向受力斜桩所增加的钢筋用量不多， 可在正常配筋范围 内满足要求。 3.6伸缩缝闭合后的处理
以上的按单个分段结构的计算方法适用于纵向变形量未达到伸缩缝闭合的情况。当 纵向变形量使伸縮缝闭合后， 纵向力或温差可采用分阶段计算。
纵向力或温差宜逐个按恰好达到伸缩缝闭合状态分阶段，各阶段增量纵向力或温差 按闭合区的全体分段结构计算，最后将内力进行叠加。纵向力或温差的各分阶段增量可 以不同， 只要满足恰好达到伸缩缝闭合状态即可， 可根据计算方便划分各分阶段增量。 根据线性叠加原理， 最后叠加得到的内力及变形总是相等的。
如船舶系缆跨越两结构分段，且系缆力大于两分段相互靠拢力， 则可将系缆力分为 两阶段。第一阶段为分段恰好闭合的系缆力， 按单个分段计算； 第二阶段为总系缆力减 去第一阶段系缆力后的差值， 按两结构分段计算。 最后进行内力叠加。
3.7计算示例
假定某码头断面如图 20所示
排架间距 8m;排架榀数 41 ;分段长度 32½；平台宽度 36. 5m;码头顶面高程 7. 7m; 码头前沿泥面高程- 20. 5m; 地基 m=3000kN/m4; 斜桩采用钢管桩 Φ 1200 δ 18， 斜度 3. 5: 1， 扭角 16° ； 直桩采用大管桩 Φ 1200 δ 145; 桩顶高程 3. 0m; 桩长 56m; 按铰接考虑； 钢管桩 6^=23350001^. m2、 T,=3. 178m、桩顶 KfS^OOOkN/m;大管桩 E2I2=2453000kN. m T2=3. 210m、 桩顶 K2=400000kN/m。 面板预制部分厚度 0. 3m、 现浇部分厚度 0. 2m、 磨耗 层厚度 0. 1m; 下桩帽高度 2m。 梁截面如下：
编号 截面名称 类型 参数
1 横梁 参见图 21 B=1. 8、 H=2. 67、 bl=1. 4、 C30 hl=. 2、 h2=. 2、 h3=. 5
2 纵梁 参见图 22 B=1. 4、 H=2. 6、 bl=l、 C35 hl=. 2、 h2=. 2、 h3=. 5
3 轨道梁 参见图 23 B=2. 4、 H=2. 6、 bl=2、 C35 hl=. 2、 h2=. 2、 h3=. 5 纵梁布置如下:
纵梁序号 中心坐标 X(m) 纵梁类型
1 3.5 轨道梁
2 13.5 纵梁
3 23.5 纵梁
4 33.5 轨道梁 桩位布置如下
桩号 1 2 3 4 5 6 7 8 9 坐标
2 3.5 5 12.3 15.2 22.3 25.2 32 35
X(m) 现按混凝土收缩等效温差取 5〜15°C, 气象温差取最低 3°C、 最高 30°C， 纵梁安装 施工温度 20°C; 荷载在纵向水平力 8000kN作用下时， 结构纵向计算如下：
最大膨胀温差 Δί = t2 - tg - tc =30-20-5=5 °C
最大收缩温差 At = ig -t, +tc2=20-3+15=32°C
以最大收缩温差 32°C为控制。
边缘第 1排架基桩因收缩温差产生的桩顶最大水平位移为：
ξ = / X At X 7=0.00001*32* 8*20=0.0512m=51.2mm
边缘第 2排架基桩因收缩温差产生的桩顶最大水平位移为：
Figure imgf000018_0001
(1)温差产生的钢管桩与大管桩内力
①钢管桩内力
与竖直线的夹角 a=atan(l/3.5)=15.9° 、 0=90-16=74°
第 1排钢管桩相对轴向位移 =3.87mm， 侧向位移 η=-49.22ηιηι， ζ =-13.57mm 第 2排钢管桩相对轴向位移 ξ=3.67ιηηι， 侧向位移 η=-46.72πιιη， ζ =-12.88mm 泥上长度 L=(3.0+20.5)/cos(15.95)=24.44m
侧向刚度 v = 2335000
2.441 * 3.178J + 3.342 * 3.178' * 24.44 + 24.443 /3 + 1.751 * 24.442 * 3.17
=256.8kN/m
第 1排轴力 N=1316kN 、 桩顶剪力 Q n=12.64kN、 Q ; =3.48k , 泥下最大弯矩 M =323kN.m、
Figure imgf000019_0001
第 2排轴力 N=1248kN、 桩顶剪力 Q n=12.00kN、 Q , =3.31k , 泥下最大弯矩 M =306kN.m、 Mc=84kN.m
②大管桩内力
泥上长度 h=23.5m
水平刚度
2 2.441 * 3.2103 + 3.342 * 3.2102 * 23.5 + 23.53 /3 + 1.751 * 23.52 * 3.21
kN/m
第 1排桩顶剪力 Q=294.8x51.04/1000=15.0kN、轴力 Qt=0， 泥下最大弯矩 M=369kN.m 第 2排桩顶剪力 Q=294.8x48.45/1000=14.3kN、轴力 Qt=0，泥下最大弯矩 M 352kN.ni
(2)纵向水平荷载产生的钢管桩与大管桩内力
单元整体刚度为：
V=340000*sin2(15.9)xcos2(74)+256.8x[sin2(74)+cos2(15.9)xcos2(74)]=2194 kN/m 钢管桩总数为 4*41=164根， 合计钢管桩水平刚度为>11=164*2194=359816 kN/m 大管桩总数为 5*41=205根， 合计大管桩水平刚度为 J2=205*294.8=60434 kN/m 平台水平总刚度 J=359816+60434=420250 kN/m
平台水平位移 Δ -8000/420250=0.0190m=l 9.0mm
产生的钢管桩内力为： 轴力 N=488kN、 桩顶剪力(^=4.671^、 Q;=1.29kN 产生的大管桩内力为： 桩顶剪力 Q=5.57kN、 轴力 Qt=0
(3)纵向桩帽与纵梁内力
以叉桩上的桩帽与纵梁为例：
① 温差产生桩顶位移 51.2mm，轴力 N=1316kN，按静力平衡计算桩帽顶平面内力： N=0 ， Qy=2194*0.0512*2=225kN ， Qx ^ 1316/3.5*2*cosl6 。 =723kN ，
Mz=2194*0.0512*2.9-326kN.m ， My ^ 1316*2.9*cosl5.9 ° =3670kN.m ，
Mx=225*2=450kN.m。 第 1排纵梁底力矩： M1=225*2=450kN.m， 取纵梁支座内侧弯矩 450kN.m， 外侧 0。 第 2排纵梁底力矩： 1^=2194*0.0486*2*2=4261^^， 取纵梁支座内外侧弯矩 426/2=213kN.m。
② 荷载产生桩顶位移 19.0mm， 轴力 N=488kN， 纵向荷载产生的桩帽内力可以不 计。 荷载产生的桩帽底剪力为： Q=2194*0.0190*2=83kN， 纵梁下力矩为 M2=83*2=166kN.m, 第 1排纵梁内侧弯矩取 166kN.m, 内侧弯矩取 0; 第 2排纵梁内外侧 弯矩均取 83kN.m。
③温差产生的轨道梁最大拉力计算：
温差纵向位移零线一侧的平均纵向位移： A =51.2/2=25.6mm
每排架的纵向水平刚度： U=420250/41=10250 kN/m
全纵截面最大拉力： N =10250*20*25.6/1000=5248 kN
按每根轨道梁面积比例所承担的温差拉力为：
N=5248*2*2.6/(2*2.6*2+2.6* 1 *2+0.5*30.5)=884 kN
4横向分力在各排架上的分配
船舶作用力是高桩码头承受的主要荷载之一，其横向分力在各排架上的分配问题， 是码头结构可简化为排架计算的前提条件，排架的横向分力取值对结构的计算结果影响 较大。 目前在高桩码头设计中， 横向分力在各排架的分配是按弹性支承刚性梁法（以下 简称刚性梁法）计算， 这种方法应用简便， 一般情况可査表确定。 目前码头平台宽度与 分段长度的变化幅度较大，平台宽度可从小于 20m到大于 50m，分段长度有些己达到 95m 甚至更长； 随着大直径桩的应用， 桩基的水平刚度也比传统的小直径方桩增大多倍； 对 分段长度与平台宽度之比很大、排架水平刚度较大的码头， 以及本文所提出的分段长度 可达 200m以上的码头， 是否仍可采用刚性梁法或如何计算也需要研究。
本发明研究了横向分力在各排架上的分配问题， 解决以下两个问题： 1、 在什么条 件下可釆用刚性梁法， 在什么条件下应采用弹性梁法； 2、 当平台与排架确定时， 分段 超过多少跨后对减小排架承担的船舶水平力影响不大，由此确定结构分段不宜超过的长 度。
4. 1 选择计算方法的判定条件
理论分析可知： 在分段长度范围内， 分段平台水平刚度相对于排架水平刚度的分 段水平相对柔度系数可用无量纲参数 4 /(E/a)表达，式中 为排架水平刚度 (kN/m)、 L 为分段两边缘排架的距离 (m)、 E为计算模量 (kN/m2) , /为上部结构的水平惯性矩 (m4)、 a为排架间距 (m)。 由于结构计算的控制内力一般发生于边缘 1、 2榀排架， 船舶撞击力 或系缆力对结构的最不利作用点也在 1、 2榀排架， 因此研究什么条件下宜采用弹性梁 法， 只需比较 1、 2榀排架的内力计算结果即可。 弹性梁法的计算可利用高桩码头纵梁 (轨道梁）内力计算软件解决，根据实际工程可能发生的分段水平相对柔度的对数变化 范围以及不同的分段跨数情况， 第 1、 2榀排架按弹性梁法计算得到的横向分力分配系 数如表 4-1-1所示。
表 4-1-1 按分段水平相对柔度及分段跨数计算排架横向分力分配系数
5跨 7跨 10跨 20跨
Figure imgf000021_0001
1-1 1-2 2-2 1-1 1-2 2-2 1-1 1-2 2-2 1-1 1-2 2-2
-∞ (刚 0.52 0.38 0.29 0.41 0.33 0.27 0.31 0.27 0.23 0.17 0.16 0.15 性梁） 4 1 5 7 3 4 8 3 6 8 5 3
0.52 0.38 0.29 0.41 0.33 0.27 0.31 0.27 0.23 0.17 0.16 0.15
4 1 5 7 3 4 8 3 6 8 5 3
0.52 0.38 0.29 0.41 0.33 0.27 0.31 0.27 0.23 0.17 0.16 0.15
5 1 5 8 3 4 9 3 7 8 5 3
0.53 0.37 0.29 0.42 0.33 0.27 0.32 0.27 0.23 0.18 0.16 0.15
5 9 7 6 5 5 5 6 8 2 7 5
0.60 0.36 0.31 0.49 0.34 0.28 0.37 0.29 0.24 0.21 0.18 0.17
8 1 2 0 2 2 7 6 9 2 9 0
0.79 0.27 0.41 0.67 0.33 0.32 0.54 0.34 0.28 0.32 0.26 0.22
7 9 5 9 5 9 9 4 7 8 4 4
0.93 0.71 0.86 0.21 0.52 0.75 0.30 0.37 0.50 0.33 0.22
0.116
9 5 7 5 1 7 4 7 7 7 7
0.99 0.02 0.94 0.97 0.06 0.84 0.91 0.14 0.64 0.71 0.32 0.34
1 0 6 0 2 0 8 9 6 6 4 8 说明： 表中第二行的 I-J表示当横向分力作用于第 I排时， 第 J排所分配的横向分力系数， 根据力学原理有 I-J=
J-I。
在工程设计中， 结构内力的允许误差为 5%， 本发明按照弹性梁法与刚性梁法计算 结果的误差小于 5%为原则确定可采用刚性梁法的条件。 由于计算排架水平力分配仅需 确定梁与支座的相对刚度即可， 因此对刚性梁情况只需确定各排架的相对水平刚度， 当 各排架水平刚度相等时， 不必计算排架横向刚度， 等跨排架可按规范査表确定。
根据表 4-1-1分析可得： 当 lg[A£4 l{EIa)] < 1.4、 即 kL* /(ΕΙα) < 25时， 弹性梁法与 刚性梁法计算结果的最大误差不大于 5%， 可按刚性梁法计算， 此时计算结果的比较见 表 4-1-2。
表 4-1-2 弹性梁分段水平相对柔度^ l(EIa) = 25时与刚性梁的横向分力分配系教比 较
5跨 7跨 10跨 20跨 计算情况
1-1 1-2 2-2 1-1 1-2 2-2 1-1 1-2 2-2 1-1 1-2 2-2 弹性梁分段柔度
0.550 0.375 0.300 0.439 0.336 0.276 0.335 0.280 0.240 0.187 0.172 0.158 kL l(EIa) = 25
刚性梁时
0.524 0.381 0.295 0.417 0.333 0.274 0.318 0.273 0.236 0.178 0.165 0.153 kL4 1{ΕΙά) = 0 弹性梁
1.050 0.984 1.017 1.053 1.009 1.007 1.053 1.026 1.017 1.050 1.042 1.033 刚性梁
由表 4-1-2可知： 当码头平台分段满足 4 /(E/a) < 25时， 第一榀排架产生的误差 最大， 但最大误差在 5%以内， 横向分力分配可按刚性梁法计算。
由于按弹性梁法计算相对较复杂， 有些设计人员不愿采用， 因此有必要探讨在什 么条件下应按弹性梁法计算，否则结构设计有可能超出允许误差。考虑到码头结构的设 计内力在多数情况下由第二榀排架控制， 一般要求第二榀排架误差不大于 5%。 但第一 榀排架的计算误差也不宜大于 10%， 否则容易导致第一榀排架的内力组合超出工程允许 范围。本文按第二榀排架误差不大于 5%、第一榀排架误差不大于 10%， 确定应采用弹性 梁法计算的条件。 经分析可得： 当 lg[ 4 /(E/a)] > 1.7、 kL4 /(EIa) > 50 , 应采用弹 性梁法， 此时计算结果的比较见表 4-1-3。
表 4-1-3弹性梁分段水平相对柔度 4 1{ΕΙά) = 50时与刚性梁的横向分力分配系数比较
5跨 7跨 10跨 20跨 计算情况
1-1 1-2 2-2 1-1 1-2 2-2 1-1 1-2 2-2 1-1 1-2 2-2 弹性梁分段柔度
0.572 0.37 0.304 0.458 0.339 0.278 0.351 0.286 0.244 0.197 0.178 0.163 kL4 l(EIa) = 50
刚性梁时 0.524 0.381 0.295 0.417 0.333 0.274 0.318 0.273 0.236 0.178 0.165 0.153 kV l{EIa) = 0 弹性梁
1.092 0.971 1.031 1.098 1.018 1.015 1.104 1.048 1.034 1.107 1.079 1.065 刚性梁
由表 4-1-3可知： 当码头平台分段满足 4 /(E/a) > 50时， 第一排架产生的误差会 大于 10%， 因此应采用弹性梁法计算。
根据以上计算结果并综合分析可知： 当 4 /(E/a) < 25时可采用刚性梁法； 当 4 /(E/fl) > 50时应采用弹性梁法；当 /(E/a)在 25〜50范围内时，有条件时宜釆用弹 性梁法，若按刚性梁法计算第一排架分配系数宜增加 10%,第二排架分配系数宜增加 5%。
4. 2 有效减小排架承受横向分力的最大分段长度或跨数
码头分段长度越长， 全分段范围结构的水平柔性就越大， 当分段长度达到一定数 值后，继续增加分段长度对减小排架承担的船舶撞击力或系缆力就影响不大。根据理论 分析可知：码头平台的单跨水平相对柔度系数可用无量纲参数 fe 3 /(EI)表汰，在实际工 程可能发生的单跨水平相对柔度变化范围内， 第 1、 2榀排架按不同跨数弹性梁计算的 横向分力分配系数如表 4-2-1所示。
表 4-2-1 按单跨水平相对柔度及分段跨数计算的排架横向分力分配系数
跨 -1 -2 -3 -4 = (刚性）
1-1 1-2 2-2 1-1 1-2 2-2 1-1 1-2 2-2 1-1 1-2 2-2 1-1 1-2 2-2
4 0.629 0.384 0.312 0.603 0.398 0.301 0.600 0.400 0.300 0.600 0.400 0.300 0.600 0.400 0.300
5 0.582 0.367 0.306 0.531 0.379 0.296 0.525 0.381 0.295 0.524 0.381 0.295 0.524 0.381 0.295
6 0.560 0.3S4 0.298 0.477 0.357 0.289 0.466 0.357 0.286 0.464 0.357 0.286 0.464 0.357 0.286
7 0.551 0.347 0.292 0.438 0.336 0.276 0.419 0.334 0.274 0.417 0.333 0.274 0.417 0.333 0.274
8 0.549 0.344 0.289 0.410 0.319 0.265 0.381 0.312 0.262 0.378 0.311 0.261 0.378 0.311 0.261
9 0.549 0.344 0.289 0.390 0.306 0.256 0.351 0.293 0.249 0.346 0.291 0.249 0.345 0.291 0.248
10 0.549 0.344 0.289 0.377 0.296 0.249 0.352 0.276 0.238 0.319 0.273 0.237 0.318 0.273 0.236
11 0.549 0.344 0.289 0.369 0.290 0.244 0.305 0.261 0.227 0.296 0.257 0.226 0.295 0.256 0.225
12 0.549 0.344 0.289 0.365 0.286 0.241 0.287 0.248 0.218 0.276 0.242 0.215 0.275 0.242 0.214
13 0.549 0.344 0.289 0.362 0.284 0.239 0.273 0.237 0.210 0.259 0.230 0.205 0.257 0.229 0.204 0.549 0.344 0.289 0.361 0.283 0.237 0.262 0.228 0.203 0.244 0.218 0.196 0.242 0.217 0.195
0.549 0.344 0.289 0.361 0.282 0.237 0.252 0.221 0.197 0.231 0.208 0.188 0.228 0.206 0.187
0.549 0.344 0.289 0.361 0.282 0.237 0.228 0.200 0.179 0.184 0.169 0.156 0.177 0.164 0.153
0.549 0.344 0.289 0.362 0.284 0.239 0.223 0.195 0.174 0.158 0.146 0.136 0.145 0.137 0.129
0.549 0.344 0.289 0.361 0.283 0.237 0.223 0.195 0.174 0.143 0.133 0.125 0.123 0.117 0.111
0.549 0.344 0.289 0.361 0.282 0.237 0.223 0.195 0.174 0.136 0.127 0.119 0.107 0.102 0.098
0.549 0.344 0.289 0.361 0.282 0.237 0.223 0.195 0.174 0.133 0.124 0.116 0.094 0.091 0.087 注： 表中粗线以下的跨数对减小排架承受横向分力基本无效。
根据表 4-2-1经回归分析可得： 跨数" = 3.5 * [Aa3 /(E/)]— °·25， 即 4 /(E/fl) = 150时， 是有效减小排架横向分力的最大跨数，设计分段不宜超过该跨数。否则一般经济技术效 果不好， 当然，设计确定最大分段长度还应考虑满足纵向温差变形及混凝土收缩变形等 要求。
4. 3 有关计算参数的取值
上部结构的水平惯性矩宜按磨耗层、 面板及纵梁组成的板梁结构计算。 为简化起 见， 可将该板梁结构转化为矩形， 其宽度 B等于平台宽， 厚度 t按等效体积确定， 水平 惯性矩按 / = 1 / 12 * / * 确定。 计算模量可近似取 E = 0.85EA， 其中 为上部结构的混 凝土模量。
排架水平刚度可由横向排架计算软件解决， 是在横梁轴线处施加单位水平力 （如 船舶单位挤靠力）所产生排架水平位移的倒数。排架水平刚度的变化对排架水平力的分 配不会敏感， 不必采用很精确的计算方法， 没有弹性梁计算软件时， 也可近似按桩顶无 竖向位移， 根据桩顶的轴向、 侧向刚度以及桩的倾斜角确定。
4. 4 算例
如某码头平台宽 16m， 排架间距 8m， 分段跨数 9跨， 平台磨耗层、 面板及纵梁组 成的板梁结构水平刚度等效于宽 16m、 厚 0. 9m的矩形， / = 0.9/ 12 * 163 = 300/«4， 计算 弹模取 E =25000000kPa， 下横梁宽 1. 5m、 高 1. 3m， 上横梁宽 0. 9m、 高 2. 2m， 每排架布 置 6根 Φ 1000大管桩，其中 2根直桩， 2对 4: 1叉桩，计算桩泥上高度 19m， O1500000kN/m。 通过排架计算得知： 当在横梁轴线位置施加 1000kN水平力时， 排架产生的水平位移为 0. 00676m。
计算得： k=1000/0. 00676=145000， L=8*9=72m,
kL4 /(E/a) =145000*72 "4/ (25000000*300*8) =64. 9。 由于 4 /(E/a) > 50， 故宜按弹性计算。
利用高桩码头纵梁 （轨道梁） 的弹性支承弹性梁程序计算结果与刚性梁法比较如 表 4-4-1所示。
表 4-4-1 弹性梁与刚性梁的计算差别
9跨情况 1、 2排架分配系数 1-1 1-2 2-2 弹性梁分段相对柔度 AZ4 1(ΕΙά) = 64.9时 0.390 0.306 0.256
刚性梁 0. 345 0. 291 0. 248 弹性梁 /刚性梁 1.130 1.052 1.032 从上表中可知： 采用刚性梁计算的最大误差为 13%。
有效减小排架横向分力的最大跨数为" = 3.5 * [^3 /(E/)]_ °25 =11.10=11跨。
5长分段结构的布置
离岸深水长分段结构可达 200m以上， 与常规结构相比具有明显的不同， 存在过去 常规码头设计不曾遇到的问题，其最大特点是在混凝土收缩与气象温度变化作用下，结 构会产生较大的纵向伸缩变位及纵向内力， 从而会导致桩基和结构的损坏。
温差产生的变位及内力随基桩在分段中所处的不同位置而不同， 其分布状态是： 在分段中间的温差纵向位移零线处基桩的变位及内力为零、而位于分段两端的基桩其变 位及内力最大、 期间按曲线过渡。
目前高桩码头结构通常采用以下布置方案：
(1)桩基布置通常采用各排架叉桩沿横向布置、但横向偏角较大（通常在 18~26° ) 0 由于采用横向偏角较大的叉桩可提高码头的纵向抗力， 同时施工也容易避免碰桩，在横 向偏角不大（通常小于于 26° )的范围内对码头的横向抗力影响也不大， 因此对常规分 段结构， 叉桩采用横向偏角较大布置是经济合理的。
(2)在分段两端（通常在第二排架处）还可根据抵抗纵向水平力的需要布置纵向受 力叉桩。 由于常规分段温差产生变形小， 桩产生的温差轴力及弯矩可以忽略不计， 而第 二排架处通常桩与横梁的内力最大， 因此将纵向受力叉桩布置在第二排架，可达到即能 提高码头的纵向水平抗力、 又能减小桩与横梁的最大内力， 是经济合理的。
. (3)对离岸深水码头桩顶一般采用刚接连接， 利用桩的抗弯能力提高码头的水平抗 力及增强水平刚度。 由于在常规分段条件下， 分段中的排架跨数少、基桩承担的水平力 较大,而离岸深水码头桩基所允许的桩斜度较小、利用叉桩轴力抵抗水平力的效果较差， 因此一般需要利用桩的抗弯能力提高水平抗力。为充分利用桩身抗弯能力以提高水平抗 力， 桩顶需采用刚接连接， 通常采用混凝土桩不能满足码头抵抗水平力的要求， 还需要 采用钢管桩，利用钢管桩可增大桩斜度并利用钢管桩的高强抗弯性能满足码头的水平抗 力要求。
(4)排架间距一般采用等间距布置。 常规分段排架数量少， 若采用不等间距的排架 布置，其减少的工程量与增加的施工难度相比并没多少优势，采用等间距布置可减少构 件类型， 方便施工， 提高施工速度。
对长分段码头而言， 结构的分段长度在技术上主要受温差产生的桩轴力或桩弯矩 控制， 在常规结构布置方案的基础上， 需要考虑以下几个问题：
(1) 由于在长分段两端附近桩顶温差产生的纵向变位大， 排架若采用大横向偏角的 叉桩或布置纵向受力叉桩都会产生较大的温差桩轴力，对长分段结构受力非常不利。而 长分段结构如果叉桩均采用小横向偏角布置、又不设置纵向受力叉桩，则纵向水平抗力 较弱，而且难以满足纵向抗震要求，为此需要研究桩基应如何布置才能达到既能减小温 差轴力， 又能满足纵向水平抗力要求， 使桩基整体受力最优、 技术经济合理。
(2) 当桩的温差弯矩对分段长度起控制作用时， 桩顶采用刚接形式会限制码头的分 段长度。采用铰接形式产生的桩温差弯矩较小， 可达到增加分段长度、减小基桩分担水 平力， 从而补偿桩顶刚接所提高水平的抗力及刚度的效果。 一般来说， 水深越大、斜桩 比例越多， 则桩顶刚接产生的优势越差， 对离岸深水码头， 可能桩顶铰接更具有优势。 此外， 离岸深水码头往往在风浪较大的条件下施工， 实际上也很难做到桩顶刚接， 有些 码头晃动较大、而按桩顶刚接计算的水平位移却小于实测位移值，有可能就是施工未能 做到桩顶刚接的原因。 由于铰接的计算模式是允许连接点转动， 因此更能适应在风浪较 大环境下施工， 是更适合外海工程的连接形式， 宜优先采用铰接。
(3)采用等间距排架布置时， 位于边缘 1〜2排架的结构内力往往起控制作用。 若 长分段码头分段内的排架数量众多， 则通过减小边缘排架间距， 可使边缘排架的基桩、 纵横梁内力减小并接近中间排架的内力，从而减小构件的设计控制内力。当长分段结构 中间排架数量较多时，减小边缘排架间距所增加的施工难度与减小中间大量构件设计内 力所降低的工程量相比一般是值得的。
针对长分段结构的特点， 本发明采用以下技术方案：
(1)距温差纵向位移零线 25m以外的叉桩均采用小横向夹角布置 （如图 1的 B区 桩 3)， 以减小纵向伸缩产生的叉桩轴力。 为平衡温差变形对上部结构的影响， 宜采用 成对布置的叉桩。当全部采用混凝土桩难以抵抗横向水平荷载时，可将分段两端一定范 围内的叉桩改用斜度较大的钢管桩代替（如图 1的 F区桩 5)。
(2)距温差纵向位移零线 25m以内的叉桩沿纵向受力布置（如图 1的 A区桩 2)， 必要 时还可将一部分承载力有富余的直桩也布置成纵向受力斜桩， 以提高纵向抗力。
(3)采用桩顶铰接形式使分段长度增大、 基桩承受的水平力减小， 从而补偿桩顶刚 接所提高水平抗力及刚度。桩顶铰接形式可分区段采用不同的连接结构：对桩顶弯矩小 于桩身强度的位于中间区段基桩， 桩顶铰接可采用常规做法， 即桩顶伸入上部混凝土 5~10cm即可；而对桩顶弯矩可能大于桩身强度的位于分段边缘区域的基桩，桩顶铰接应 采用降低桩顶弯矩的创新铰接连接结构， 在本发明说明书第 6条中将叙述这种新型连接 结构。
(4)减小边缘排架的间距， 使边缘排架的基桩、 纵梁、 横梁内力减小并接近中间排 架的内力， 尽量使中间排架内力作为构件设计的控制内力， 以进一部降低造价。
5.1桩顶位移对各种不同情况基桩产生的内力分析
为研究桩基方便起见， 首先分析单桩在桩顶发生固定位移时，各种不同情况下的基 桩所产生的内力及其变化规律。
假定桩顶发生 10mm水平位移， 现比较不同桩顶连接、 不同泥上高度、 不同斜度、 不同桩径等条件下基桩产生的内力。
由于离岸深水长分段结构主要采用混凝土桩，因此选择以 PHC桩为例进行计算与比 较。 设混凝土标号 C80， E取 39000000kPa, 由于地基 m值越大产生的内力越大、 因此计 算比较时主要取偏大值 10000kN/m4， 当直径为 lm时， 取壁厚 0.130m， 极限承载力 12500 kN, (桩身 A=0.355m3， I=0.0356m4, 相对刚度 T=2.335m：)。 当直径为 1.2m时， 取壁厚 0.145m, 极限承载力 12500*1.2=15000 kN, (桩身 A=0.481m3， 1=0.0713m4, 相对刚度
T=2.587m)， 桩顶的轴向反力系数按 = 1- ， 其中 C取 130/m确定。 各种
/(EI) + l /(CQud) 不同情况计算的结果见表 5-1-1。 桩顶水平位移为 10mm时各种不同情况的基桩内力计算结果比较
Figure imgf000028_0001
20m 径
斜度 (m) 1.2 1032 5.3 0 113 1032 21.2 264 190
6： 1
髙度 1.0 1220 13.9 0 154 1220 54.5 390 234 桩
10m
径
斜度 1.2 1561 25.4 0 283 1561 98.8 729 422 (m)
6： 1
高度 1.0 1559 37.2 0 265 1559 141.3 725 361 桩
6m
径
斜度 1.2 1964 65.2 0 476 1964 245.4 1316 630 (m)
6： 1
桩径 m 0 14.5 0 159 0 56.9 403 241 地
lm
高度 m/5 0 10.5 0 119 0 40.3 317 169 m
10m
桩径 m 0 3.0 0 61 0 11.7 142 105 地
lm
基
高度 m/5 0 2.4 0 52 0 9.6 124 84 m
20m
桩径 m 0 5.6 0 117 0 22.3 273 197 地
1.2m
高度 m/5 0 4.5 0 97 0 17.9 236 154 m
20m
直径 1 反 K 1220 13.9 0 154 1220 54.5 390 234 高 10m 力
斜度 系 K/2 610 13.9 0 154 610 54.5 390 234 6： 1 数
当桩顶产生相同的水平位移时， 从上表可以分析得到以下基桩内力的变化规律:
(1)桩的弯矩随泥上高度的减小而迅速增大。 (2)桩的最大弯矩采用铰接时比采用刚接时普遍减小一倍以上； 泥下弯矩采用铰接 时比采用刚接时小 30%〜60%; 随着泥上长度减小、 比值增大。
(3)桩的倾斜度对弯矩和剪力影响不大， 但对轴力影响较大。
(4)桩轴力与桩顶轴向反力系数、 斜度 sin( a )及横向偏角 Sin( e )成正比；
(5)桩的轴向反力系数对桩身弯矩无影响。
(6)桩径越大产生弯矩越大，经分析知弯矩产生的桩身最大应变近似与桩径成正比。
(7)地基水平反力系数 m对弯矩和剪力影响随着桩泥上长度的增大而减小。 如桩径 为 1.0m的直桩， 当地基水平反力系数 m从 lOOOO kN/m4降到 2000 kN/m4时， 泥上长度 10m 时弯矩降低约 40%， 泥上长度 20m时弯矩降低约 20%。
(8)刚接桩依靠桩顶弯矩所提高的水平抗力随着桩的泥上高度、 桩斜度、 桩轴向刚 度而减小， 随着桩身抗弯刚度、地基水平反力系数 m而增加。如表中泥上高度 6m， 桩径 1.2m， 斜度 6 ： 1 的桩 ， 单桩桩顶刚接可增加水平抗力 比值约 (245.4-65.2)/(1964/6)=0.551=55.1%； 而泥上高度 10m， 桩径 1.0m， 斜度 4: 1的桩， 单桩 桩顶刚接可增加水平抗力比值约 (51.8-13.2)/(1783/4)=0.087=8.7%。
5.2桩基布置要求
(1)传统码头允许产生的温差轴力
在传统分段长度范围内， 桩基也会产生温差轴力， 过去的经验已经证明： 在传统的 码头分段范围内， 温差产生的轴力对结构影响不大， 设计可以忽略不计。
现看看传统码头温差产生的轴力是多少？假定分段长度为 70m， 计算温差考虑 50Ό (对没有采取减小温差措施的常规码头取该计算温差并不大）， 此时分段边缘处温差位 移为：
Δ =70/2*50*0.00001 *1000=17.5mm
假定边缘叉桩按 4:1纵向布置， 叉桩轴向位移为：
=17.5/ V (l*l+4*4)=4.25mm
根据不同的桩径 （截面特征同表 5-1-1 )、 承载力及泥面长度， 计算基桩位移产生的 轴力见表 5-2-1。 不同桩径、 承载力及泥上长度产生的轴力
Figure imgf000031_0001
表中对泥上高度 20m, 斜度 4: 1偏大， 用粗斜体字表示， 仅作理论比较。
由上表可知， 当泥上长度越小、 桩轴向刚度越大， 则温差产生的桩轴力越大。 表 中桩径 1.0m的叉桩最大温差轴力与承载力之比为 0.46，桩径 1.2m的叉桩最大温差轴力与 承载力之比为 0.47。所对应的情况是： 泥上高度 5m，这种高度在岸坡码头中靠岸桩经常 遇见； 泥面刚度系数 C取规范大值 145/m， 实测轴向刚度系数离散性较大， 有不少桩的 C 值达到该值； 承载力分别为 1.0m桩 6250kN及 1.2m桩 7500kN， 实测统计小于该承载力的 桩也不少， 由于基桩的状态是传统工程设计可以允许的，实践中这种基桩状态的码头也 没有产生明显破坏，因此可以认为设计允许温差产生的轴向位移小于 4~5mm、轴力小于 承载力的 50%。 （可暂时作为长分段结构设计时基桩的温差轴向位移与轴力双控标准）。
(2)长分段码头桩基平面布置
通过分析可知： 在一定的纵向位移条件下， 桩轴力与桩顶轴向反力系数、 桩斜度 3 11( (1 )及横向偏角3^1^ )成正比。 在不同的桩基布置中， 由于桩顶轴向反力系数变化不 大， 减小桩斜度会降低码头的水平抗力也不宜采用， 因此为减小温差产生的桩轴力， 应 尽量减小叉桩的横向偏角。 由于长分段结构两端附近温差位移大，若布置纵向受力叉桩 则会产生很大的温差轴力， 因此不能布置纵向受力叉桩。
长分段结构可减小基桩承受的水平力， 有利于采用混凝土桩基代替钢管桩， 在可 能的情况下宜尽量采用混凝土桩。对于深水码头， 由于码头承受的水平荷载大、桩的泥 上高度大抵抗水平力能力差、混凝土叉桩的斜度又受到限制， 因此长分段结构全部采用 混凝土桩有时也难以满足码头抵抗横向水平力的要求，这时可将分段两端靠近边缘若干 排架区域的叉桩换成可采用倾斜度较大的钢管桩代替。 （如图 1的 F区桩 5)。
采用钢管桩代替混凝土叉桩时， 钢管桩应增加斜度， 充分利用钢管桩可增加的斜 度提高叉桩的水平抗力， 以减小钢管桩替代叉桩的区域长度及增加码头的水平抗力。一 般来说，分段两端附近排架区域叉桩采用钢管桩代替混凝土桩的数量随着分段长度的增 加而相对比例减小， 即分段长度越长、采用钢管桩的比例越低。钢管桩替代叉桩的尺寸 及区域长度由结构计算确定。
如果叉桩均采用小横向偏角、 又不布置纵向受力叉桩， 则纵向水平抗力较弱， 而 且不能满足纵向抗震要求， 为此可将位于温差纵向位移零线 25m、 且不大于分段长度的 1/6范围 （如图 1的 A区） 以内的叉桩布置成与纵向夹角小于 45° 的纵向受力桩 （如图 1 桩 2) ， 必要时还可将一部分承载力有富余的直桩布置成纵向受力斜桩， 以增强码头的 纵向水平抗力。其理由是： ①靠近温差纵向位移零线附近桩顶的温差变位小， 布置改为 纵向受力斜桩不会产生较大的温差内力，过去的经验已证明是可靠的；②从结构受力分 析上看， 中间排架所分担的横向水平力分配系数相对比较小，横向叉桩的水平抗力不能 充分发挥，将叉桩改成纵向受力布置以抵抗纵向水平力和地震力是合理的；③该中间区 域长度内的叉桩数量较多，改为纵向受力斜桩后一般能满足结构纵向抗力要求；④长分 段码头由于两端抵抗水平力的横向叉桩较多，因此当这些中间排架叉桩改为纵向受力布 置后， 中间排架所承受的横向水平力可转由两边排架承担，对中间排架的抵抗横向水平 抗力影响不大。
中间区域叉桩以及承载力有富余的直桩也可根据需要改为纵向受力斜桩， 斜桩数 量及斜度宜根据结构抵抗纵向水平力及纵向抗震要求计算确定，纵向桩的斜度可比横向 叉桩的斜度小些。
在纵向荷载作用下， 分段边缘基桩纵向内力宜小于 1/3桩身允许值， 以预留允许温 差产生的桩内力。
(3)叉桩横向偏角的确定及减小横向偏角措施
叉桩的最小横向偏角与桩径、 桩距以及打桩偏差等因素有关。 打桩偏差应考虑： 桩顶水平面偏位、方位角偏差、仰俯角偏差、左右摆动角偏差等， 在确保不会发生碰桩 的前提下， 应尽量减小叉桩的横向夹角， 一般横向夹角不宜大于 10~18° 。
当温差产生的桩轴力成为分段长度的控制条件时， 对温差桩轴力超出允许值的长 分段边缘附近区域， 排架桩基可采用以下减小横向偏角的措施：
①将可能碰桩的相邻直桩 （如 1桩 4) 改为斜度不大于 20: 1的反向纵向斜桩； ②斜桩桩顶与可能碰桩的相邻直桩桩顶采用偏离排架轴线约 10cm左右错开布置 （如 图 1中桩 3的桩顶偏右 10cm， 桩 4的桩顶偏左 10cm)。
打桩施工应釆取保证措施， 要特别注意控制斜桩的方位角、 左右摆动角的偏差， 以及相邻直桩的偏差， 确保打桩不发生碰桩并使误差控制在允许范围内。
例如：某码头的计算温差为 50°C，叉桩斜度为 4: 1，按桩的温差允许轴向位移 4mm 控制.
假定未采取减小横向偏角措施前， 叉桩的最小横向夹角为 18° ， 此时允许的分段 长度约为：
Ll=2*4/(50*0.00001*1000*/4.1*sinl8° )=212m
假定釆取减小横向偏角措施后， 叉桩的最小横向夹角为 10° ， 此时允许的分段长 度约为：
Ll=2*4/(50*0.00001*1000*/4.1*sinl0° )=378m
本例的长分段结构可在中间 212m范围内取横向夹角 18° ， 不采用减小横向偏角措 施； 而在该区域以外至分段边缘的 212~378m范围， 则应采取减小横向偏角措施， 使横 向夹角不大于 10° 。
(4)不宜选用过大的桩径
因为由温差桩身弯矩产生的应变大致与桩径成正比， 桩径选择越大则越容易发生 桩身开裂或破坏。桩径的选择应考虑包括桩距、横向夹角等因素在内综合确定。 当桩基 弯矩对分段长度起控制作用时， 不宜选用过大的桩径。 (5)码头平台相对刚度的控制要求
分段长度 L宜满足 kL4 1{ΕΙά) < 150或跨数 "≤ 3.5 * [EI /(ka')]02s。
5.3桩顶采用铰接与刚接的比较
当桩基弯矩对分段长度起控制作用时， 应根据下列因素比较桩顶采用刚接与铰接 方案的优劣：
①采用刚接所提高的排架水平抗力；
②采用铰接增加分段长度所减小的排架承担水平力；
③施工技术与环境是否能保证桩顶刚接满足要求；
④对刚接与铰接方案进行经济技术比较。
(1)排架采用刚接桩所提高的水平抗力的理论分析
假定桩身的抗弯能力足够大， 抗弯能满足要求， 桩基由轴向承载力控制， 则排架采 用刚接桩所提高的水平抗力比值系数可根据刚接桩与铰接桩在桩轴力相等状态下，按下 式估算：
λ = ηλ · qx + n2 - q2 + n2•N2 / )/(nl -
Figure imgf000034_0001
+ n2 - q2 + n2 - N2 la) (5-1) 式中： A——排架采用刚接桩所提高的水平抗力比值系数
«,、 n2——排架的直桩数、 斜桩数
a——斜桩的横向垂直斜率 （即横向桩斜度《: 1 )
q、、 q2——刚接时的直桩剪力、 斜桩剪力
g；、 q——铰接时的直桩剪力、 斜桩剪力
N 2——刚接与铰接时斜桩轴力相等时的斜桩轴力
如按表 5-1-1条件， 假定排架桩数 7根， 泥上高度 10m， 桩径 lm， 有 1对 4: 1的叉桩， 则桩刚铰接排架水平抗力比值约为：
λ =(56.9*5+51.8*2+1783/4*2)/(14.5*5+13.2*2+1783/4*2)=1.29。
如假定排架桩数 9根， 泥上高度 20m， 桩径 1.2m， 有 2对 6 : 1的叉桩， 地基 m=2000kN/m4, 桩承载力减半 （等效于泥面轴向刚度系数 C=65/m， 当0≠130/111时， 按 轴力与桩顶轴刚度成正比换算， 如 C=65时， 当桩径 lm，对高 10m情况，轴力为 0.685*N， 对高 20m情况， N*0.770; 当桩径 1.2m，对高 20m情况，轴力为 0.755*N)，其余条件同上， 则桩刚铰接排架水平抗力比值约为：
Λ=(17.9*5+21.2*17.9/22.3*4+1032*0.755/6*4)/(4.5*5+5.3*4.5/5.6*4+1023*0.755/6*4) =1.21。
为分析桩顶采用刚接与铰接的方案， 以下计算叉桩在不同根数、斜度、深度等情况 下桩刚铰接排架水平抗力的比值（桩的计算参数同上）， 见表 5-3-1。
表 5-3-1 刚接桩提高水平抗力系数表
Figure imgf000035_0001
Figure imgf000036_0001
lZSlOO/llOZN3/X3d 謂 OAV 11 6 20 1.0 10000 130 790 904 819 1.10
12 6 20 1.0 10000 65 608 722 637 1.13
13 6 20 1.2 2000 130 1032 1206 1076 1.12
14 6 20 1.2 2000 65 779 953 823 1.16
15 6 20 1.2 10000 130 1032 1248 1086 1.15
16 6 20 1.2 10000 65 779 996 833 1.19 表中对泥上高度 10m， 斜桩 6: 1斜度情况， 由于桩的斜度偏小， 工程少采用， 因此用粗斜体字 表示， 仅作理论比较。
从上表可知： 排架桩基的泥上高度越大、斜度越大、 桩顶轴向刚度越大、斜桩与直 桩桩数之比越大、桩径越小、地基水平刚度 m越小，则桩刚铰接排架水平抗力比值越小。
对离岸深水大型码头， 桩的泥上高度一般大于 10m， 当桩泥上高度为 10m时， 斜桩 一般采用 4: 1斜度， 考虑到大型码头平台宽度较大， 斜桩数 /直桩数一般大于 2/5, 此时 桩刚铰接排架水平抗力比值范围大致在 1.1~1.4之间； 当桩泥上高度为 20m时， 若采用桩 径为 lm、 斜度 6: 1的桩基， 则桩刚铰接排架水平抗力比值更小， 在 1.1~1.25之间， 若采 用桩径为 1.2m、斜度 6: 1时， 则桩刚铰接排架水平抗力比值在 1.1~1.4之间。综合以上情 况可知， 离岸深水大型码头桩刚铰接排架水平抗力比值范围大多在 1.1~1.4之间。
考虑到以上分析是假定刚接桩桩顶无转动的理想情况，实际刚接桩桩顶会因刚接结 构本身以及纵横梁变形等原因发生转动， 从而使桩刚铰接排架水平抗力比值有所折减。
(2)釆用铰接桩可提高码头的分段长度
假定分段长度受桩身的抗弯能力控制，对直桩情况，铰接与刚接的分段长度比值可 根据桩纵向弯矩相等的原则确定。由于温差变形与弯矩成线性比例关系， 因此也可取在 相同位移条件下刚接桩最大弯矩与铰接桩最大弯矩之比作为铰接与刚接的分段长度比 值。
现按照前面有关公式， 计算直桩在桩顶产生 10mm位移时， 不同桩基情况下的刚接 桩与铰接桩的最大弯矩比值 P (即铰刚接的分段长度比值 P )， 见表 5-3-2。 表 5-3-2直桩桩顶位移 10mm时刚接桩与铰接桩最大弯矩的比值表
Figure imgf000038_0001
由上表可知， 刚接桩与铰接桩的最大弯矩比值随着桩的泥上高度增加、 地基水平 刚度系数 m的增加、桩径减小而降低，但变化幅度不是很大，一般最大弯矩比值在 2.3~2.7 范围， 由此可知理论上直桩采用铰接桩形式可使码头分段长度增加到 2.3倍以上。
对于斜桩情况， 在前面的研究中已经知道， 在工程斜桩的斜度范围内， 斜度对桩 顶位移产生的桩身弯矩影响不大，铰刚接的分段长度比值可近似按上表确定。但斜桩对 不同的分段长度所产生的轴力有差异， 由于混凝土桩的允许弯矩与桩的轴力有关， 因此 情况比较复杂， 粗略比较时可近似假定轴力相差不大， 仍按表 5-3-2确定。
需要说明的是： 表 5-2-2是按理想的铰接形式计算的， 目前常规的桩顶铰接结构并 不适用。为达到铰接效果， 需要创新铰接连接结构， 以达到长分段结构铰接的设计要求 (见下条）。
当铰接桩连接结构能保证桩顶弯矩小于泥下弯矩时， 应根据不同铰接结构的铰接 效果对铰刚接分段长度比值进行折减， 由于桩顶弯矩变化对泥下弯矩不是很敏感，根据 上面的结构力学分析， 可取最小取折减系数为 0.8， 考虑到铰接结构总是非理想铰接， 但铰接桩只要保证桩顶不发生受弯损坏即可，桩顶弯矩对泥下弯矩影响不大，建议铰接 与刚接分段长度比值的折减系数视铰接效果情况取 0.8~0.9。
采用铰接方案时， 桩顶还应验算铰接结构的转角， 要求桩顶最大相对转角小于铰 接结构所容许的转角。
(3)分段控制所允许的桩基纵向弯矩
当桩身抗弯能力成为分段长度的控制条件时， 桩基的纵向允许弯矩（或变形）就需 要明确， 以下研究桩的纵向允许弯矩。
以管桩为例， 管桩总弯矩是由横向弯矩与纵向弯矩按向量叠加而成，假如桩身的允 许弯矩为^1， 横向承受弯矩标准值为 MA， 则纵向允许承受弯矩标准值为 Mz
Figure imgf000039_0001
长分段结构要求桩基具有一定的纵向允许弯矩值， 设计应统筹兼顾 桩基的纵横两向受力， 一般要求桩的横向承受弯矩不宜大于 0.8M, 使桩的纵向可承受 弯矩不小于 0.6M。
以下分析传统码头在刚接桩顶条件下可能产生的温差纵向内力，可作为长分段结构 控制温差内力时参考。 由于桩泥上长度越小、 地基水平系数 m越大、 地基轴向系数 C越 大则桩的内力越不利， 因此取桩泥上高度 5m、 地基轴向系数 C取 145/m。 假定分段长度 为 70m， 计算温差考虑 50°C， 此时分段边缘处温差位移 17.5mm。根据不同的桩径（截面 特征同上)、 承载力及泥上长度， 基桩位移产生的轴力见表 5-3-3。
不同桩径、 承载力及泥上长度产生的轴力
Figure imgf000039_0002
由上表可知： 传统码头由温差产生的桩顶弯矩不小， 当桩泥上高度较小、 地基 m较 大时， 温差内力有可能造成基桩开裂或损坏。
(4)采用铰接桩形式的方案比较
现以工程实例进行比较， 某 20万吨级卸船码头， 叉桩釆用 1.2m钢管桩， 直桩釆用 1.2mAl型大管桩， 桩顶高程 3.0m， 泥面高程 -20m， 地基 m取 4000 kN/m4， 排架间距 8m， 分段长度 68m， 分段跨数 8跨， 平台宽度 32m， 面板厚 0.5m， 全部纵梁折算板厚 0.4m， 排 架桩数 9根， 其中布置两对钢管桩叉桩（斜度 3.5: 1 )和 5根大管桩直桩， 泥面地基轴向 刚度系数 C=900000/m， 混凝土模量 E取 31500000kN.m2。 假定桩基布置采用本方案， 结 构分段长度受桩弯矩控制。
①排架采用刚接桩所提高的水平抗力： 经易工软件计算， 排架在 1000kN水平力作用下： 对刚接情况： 位移 10.75mm、最大 桩压力 847kN; 对铰接情况： 位移 11.23mm、 最大桩压力 872kN。
桩顶刚接排架水平刚度 k=1000/0. 01075=93000kN/m , 桩顶铰接排架水平刚度 k= 1000/0. 01123=89000kN/m。
由此可知： 刚接排架提高水平抗力比为 872/847=1.03， 提高刚度比为 11.23/10.75=1.04。
②排架采用刚接桩时所允许的分段长度：
受在荷载标准组合下， 经计算得到刚接直桩顶的横向最大弯矩 314kN.m， 最小轴力 取 0，查寻规范可知在桩轴力为 0时 A1型桩的抗裂弯矩为 700kN.m，可推知桩的纵向弯矩 允许标准值为 7002 - 3142 =625k .m。
假定允许纵向荷载产生的桩顶纵向弯矩为 0.2*625=125kN.m， 则允许由温差产生的 纵向桩顶弯矩为 0.8*625=500kN.m。
按桩顶温差弯矩 500kN.m为控制条件， 经计算得到桩顶允许位移为 23mm， 假定计 算温差取 50°C， 则允许分段长度为 2*23*0.001/50/0.0001=92m。 经验算该分段长度满足 有效减少排架水平力的要求， 排架跨数取 92/8=11.5取 11跨。
③排架采用铰接桩时所允许的分段长度：
在荷载标准组合下， 经计算得到铰接直桩泥下的横向最大弯矩为 70kN.m， 最小轴 力取 0， 査寻规范知抗裂弯矩为 700kN.m， 计算允许桩的纵向弯矩标准值为
Λ/7002 - 702 =696kN.m。
假定允许由温差产生的桩顶弯矩也取 500kN.m， 计算得到桩顶允许位移为 58mm， 同样计算温差取 50°C， 则允许分段长度为 2*58*0.001/50/0.0001=232m。考虑到铰接的非 理想情况， 取分段长度为 232*0.9=209m。
平 台 平 面 刚 度 的 等 效 板 厚 为 0.5+0.4=0.9m ， 平 台 平 面 刚 度 EI=3.15* 10Λ7/12*0.9*32Λ3=7.74* 10A1 OkN.m4 ， 要 求 分 段 不 宜 超 过 " = 3.5 * [E//(Aa3)]°25 =3.5*(7.74*10A10/(89000*8A3))A0.25=22.5跨， 取 22跨， 可取设计分 段长度 22*8+4=176m。
注意本例的分段长度是严重受到平台宽度的限制，使增加码头分段长度不能达到有 效减小排架承受水平力的作用。如使用上无特殊要求， 仅从结构造价上考虑， 当取分段 长度大于 176米时一般不能显著降低工程造价， 因此宜取 176m。
④刚接与铰接排架的水平力分配系数 刚接分段水平相对柔度系数 4 /(E/fl) =93000*92 4/ (7. 74*10" 10*8) =10<25, 因此 可按刚性梁法计算。
铰接分段水平相对柔度系数 4 /(E/a) =89000*176 4/ (7. 74*10" 10*8) =137>50, 因 此应按弹性梁法计算。
刚接与铰接的第 1、 2排架横向水平力分配系数见表 5-3-4。
表 5-3-4 刚接与铰接排架横向水平力分配系数比较表
Figure imgf000041_0001
由上表可知， 当考虑船舶撞击两排架时， 在最不利情况下桩刚接与铰接的排架分 配水平力系数之比大于 1. 36， 相比桩刚铰接排架的水平抗力之比为 1.04来讲， 采用铰接 具有明显的优势。
以上实例说明， 桩泥面长度较大时， 桩顶采用铰接可以比采用刚接更能提高码头 水平抗力， 即使铰接比刚接的码头水平抗力略低时， 如综合考虑施工及经济等因素， 有 时铰接也比刚接具有优势。 对离岸深水大型码头一般宜采用铰接连接方案。
5.4减小边缘排架跨度分析
在水平荷载作用下， 边缘排架的分配系数最大。 排架数量越多、 边缘相邻排架的 分配系数差异就越小， 如当船舶撞击边缘排架时， 对 6跨分段情况， 边缘 1、 2排架分配 系数比为 0.464/0.357=1.30 ; 对 11跨分段情况， 边缘 1、 2排架分配系数比为 0.295/0.256=1.15； 对上例的 22跨分段采用弹性梁计算情况，边缘 1、 2排架分配系数比为 0.204/0.182=1.12。对长分段结构而言， 由于排架数量众多，减小边缘排架间距对水平力 引起的桩轴力差异不是很大。
在自重荷载作用下， 由于各排架自重基本相等， 施工中纵梁的安放都在结构可形 成纵向整体受力前的简支状态，面板自重可在结构形成纵向整体受力后安装， 由于面板 自重不大、且均布恒载产生的排架纵向分担调整也不大， 因此可以近似认为由自重产生 的各排架桩轴力也相差不大。
在门机与均布活载荷载作用下， 经验表明： 通常是第 1、 2排架分担的荷载最大。 如例 5-3-1条件在分段为 8跨门机荷载作用下， 从边缘起算各排架的最大内力如表 5-4-1。 表 5-4-1 在门机荷载作用下轨道梁最大支座反力 （kN)表
Figure imgf000042_0001
由上表可知： 排架的控制荷载为 4938kN， 假如减小第一排架使 1、 2排架支座反力 接近 4282， 则门机产生的排架控制反力可降低 1-4288/4933=15%。
减小第一跨排架间距的经济性粗略比较如下：假定活荷载占全部荷载的 50%，则减 小边缘排架间距后按可减小桩力 7.5%。假定泥下桩长为两倍泥上桩长，经济比较假定泥 下桩长近似与 1/2桩轴力成正比， 则桩轴力减小 7.5%可降低桩长 2.5%， 可降低桩基费用 约 1.5%， 按桩基占结构总费用为 40%计， 可节省工程造价约 0.6%。假定长分段码头长度 150m, 相当于节省上部结构 0.9m以及减少 0.9/8=0.11个排架桩基的工程量， 椐此粗略判 断采用减小边缘排架间距所减少工程量利益要大于增加施工难度的付出，以上分析还没 有考虑到边缘第 1跨纵梁跨度减少后对纵梁设计内力的减小， 综合判断减小第一跨排架 间距是经济合理的。
6新型桩顶铰接结构
目前高桩码头铰接结构仅是采用降低桩顶伸入下横梁或帽桩高度的方式，这种常规 的铰接连接结构不能保证桩顶与下横梁或帽桩之间的自由相对转动，实际上是处于刚接 与铰接之间的一种不确定的连接方式，大纵向位移时仍有可能发生桩顶受弯损坏，这种 常规的铰接结构于仅适用于桩顶按刚接计算的弯矩小于桩身抗弯能力的情况。过去常规 码头分段长度小，温差变形产生的弯矩总是小于桩身抗弯能力，在桩顶不会发生损坏的 条件下， 虽然设计是按铰接计算， 但实际桩顶有部分刚接对于码头的受力是有利的， 是 属于设计安全预留。
长分段码头若采用桩顶刚接形式， 则温差会产生很大的桩顶弯矩， 往往会成为限 制分段长度的控制条件， 从前面的分析已知， 长分段结构一般宜采用铰接形式， 但由于 目前常规的铰接结构不能保证桩顶所需的自由转角，不能保证桩顶弯矩小于桩身抗弯能 力， 因此不能用于按刚接计算时桩顶弯矩大于桩身抗弯能力的长分段两边缘附近区域， 这将使分段长度受到很大限制。对长分段结构而言，在有效分段长度范围内，分段越长、 排架承受的水平力就越小，就越有利于采用混凝土桩代替钢管桩；对于分段两端有部分 叉桩采用钢管桩的情况，钢管桩用量并不随分段长度的增加而增加，分段长度的增大也 有利于降低钢管桩的比例。由于常规桩顶铰接结构不能用于按刚接计算时桩顶弯矩大于 桩身抗弯能力的区域， 因此需要提出一种适用于长分段结构的铰接连接新技术。 目前在公路、 铁路等行业工程中应用的铰接结构有不少形式， 但尚没有适合作为 高桩码头桩顶铰接的结构形式， 长分段码头需要解决能减小桩顶弯矩的新型铰接结构。
6.1 新型桩顶铰接结构方案
桩顶铰接连接立面示意图见图 2a;
桩顶铰接连接平面示意图见图 2b。
新型铰接结构的施工及设计要求如下：
①模板（014)、 模板挂筋（012)及环形底板（011 )整体制作， 挂筋（012)在底 板下焊接（013)。 在桩顶上涂上结构胶粘剂 （如环氧树脂）后安放整体制作后的底板。
②底板宜釆用 20锰钢等材料， 厚度约 10~20mm， 外径同桩径、 内径宜大于抗剪 钢管 （031 ) 的外径 3〜5cm以上， 以便浇筑桩内混凝土。
③钢筋笼尽量取小直径，钢筋笼抗拉主筋（021 )宜采用直径不小于 28mm的 3级 钢或 2级钢， 以减小钢筋笼直径和增加连接面的允许缝隙量；抗拉主筋配筋量应满足桩 顶的抗拉要求、且产生的最大弯矩宜小于桩身的允许抗弯值。抗拉主筋在接触面附近应 进行表面滑动处理（022)， 可釆用涂抹防腐油后包裹薄膜材料， 目的是消除混凝土握裹 力以达到增加接触面的允许缝隙量；滑动处理段总长度应根据计算所需的允许缝隙量确 定； 上下段未进行滑动处理的长度需满足钢筋锚固长度要求； 由于钢筋笼直径小， 因此 可考虑将上段抗拉主筋伸出桩帽或下横梁进行锚固。
④钢筋笼外套有抗剪钢管（031 )， 抗剪钢管宜采用厚壁无缝钢管， 宜选择 20锰钢 等材料， 厚度不宜小于 30mm， 钢管截面用量需满足桩顶抗剪要求； 抗剪钢管外部也应 进行表面滑动处理，可采用涂抹防腐油后包裹薄膜材料， 目的是消除混凝土握裹力避免 产生不可控制的桩顶弯矩。
⑤钢筋笼及抗剪钢管安装后， 浇筑桩内混凝土至底板面， 在底板面涂上结构胶粘 剂后安装中板（041 )。 中板宜采用 20锰钢等材料， 厚度可取 30mm左右； 内径宜比抗 剪钢管外径大 l~2mm; 外径宜大于底板内径不小于 50mm， 以满足搭接受压要求； 中 板顶面外边缘应作成斜坡 （042)， 坡度可取 5~10° 左右， 应满足桩顶所需转角要求； 斜坡长度宜大于 100mm; 坡顶平台宽度应按局部承压计算且不应小于 50mm。
⑥在中板外空隙区可填柔性防腐填料 （063 )， 在中板顶部涂上结构胶粘剂后安装 顶板（051 )。 顶板宜采用 20锰钢等材料， 与中板接触范围的顶板厚度不宜小于 20mm， 内径宜比抗剪钢管的外径大 l~2mm， 外径同桩径。 顶板上焊接有锚固筋（052)及抗剪 板（054)，锚固筋焊缝位置见（053)，抗剪板焊缝位置见（055)。锚固筋宜采用 2级钢， 弯起角可在 30~60° 之间； 抗剪板高度可取 50mm左右。锚固筋及抗剪板应能抵抗桩顶 剪力以及钢管摩擦力，锚固筋配筋量及抗剪板尺寸由计算确定。当顶板上方的分布水平 钢筋不能通过抗剪板时， 可将水平钢筋焊接于顶板或抗剪板上。
⑦关于钢管埋入上部混凝土的长度问题， 由于抗剪钢管内为实心混凝土， 顶板与 钢管之间的接触强度一般能抵抗桩顶剪力， 如钢管直径 0.2m， 顶板厚 2cm， 按 20锰钢 抗压强度 310mPa计算，其极限抗剪力为： Qj=0.02*0.2*310000=1240kN，远大于实际桩 顶可能产生的剪力，因此钢管埋入上部混凝土长度可取 50mm左右。钢管埋入下部桩内 混凝土的长度可按 1/2桩径确定。
⑧顶板顶面至底板下的桩外侧应包裹柔性防腐材料（064)， 防腐材料应选低刚度 材料， 厚度可取 5~10mm左右， 包裹范围应超过顶板顶面和桩帽（或下横梁）底面不小 于 20mm并且伸出底板下的距离应满足防腐要求。
⑨ 中板斜坡顶平台 041宽度可按图 24计算确定， 图中板内边缘半径为 r， 斜坡顶边 缘半径为 R， 转动的局部受压面积按图中阴影所示， 阴影面积为：
A = 2R2 · arccosi— ) - r · yjR2 - r2 6-2-1
R 假定中板与顶板的抗压强度为 fy， 桩轴向设计压力为 N， 则应满足：
fy - = N 6-1-2 中板斜坡顶平台宽度 δ按下式确定：
δ =R—r 6-1-3
⑩锚固钢筋及抗剪板可按图 25计算：
图中：剪力 Qn取桩顶剪力 Q加 0.05桩顶轴力 N， 作用于桩顶上；钢管与顶板侧摩 擦合力为 P; T为锚固钢筋应达到的设计拉力； P为锚固钢筋弯器角， 抗剪板侧反力 o 取混凝土轴心抗压强度 fc; a为钢管与顶板侧摩力 P到顶板边缘的距离、 b为锚固钢筋 底板交点到顶板边缘的距离、 c为抗剪板到锚固钢筋底板交点距离、 d为侧反力中心到 桩顶剪力 Qn的距离。
抵抗剪力方向的面积 Ω应满足抵抗剪力 Qn的要求，可以考虑锚固钢筋的抗剪能力， 抗剪板面积 Ω按下式确定：
Q =(Qn-T*cos e )/fc 6-1-4 锚固钢筋除应满足抗剪钢板的锚固要求，可以侧反力中心 O为力矩轴，按锚固力 T 能抵抗剪力 Qa对 o点力矩的要求确定， 可不考虑 T的水平分力， 这部分锚固力 T1可 按下式确定-
Tl=Qn*d/(c*sin P ) 6-1-5
锚固钢筋尚应满足顶板与抗剪钢管间侧摩力 P的抗拔要求。可近似假定摩擦系数为 0.3， 即钢管侧摩力 P=0.3Qn， 这部分锚固力 T2可近似按边缘支点力矩平衡确定， 即：
T2=P*a/(b*sin 3 ) 6-1-6
以上两项叠加要求：
T= Qn*d/(c*sin β )+P*a/(b*sin β ) 6-1-7
(ID桩顶所需的相对转角根据计算铰接桩桩顶的最大转角 ω确定， 接触面所需的缝 隙量按抗拉主筋到最远斜坡顶边缘的距离乘最大转角确定， 艮卩：
ε = ρ * ω 6-1-8
式中： ε允许缝隙量 mm、 P为抗拉主筋到最远斜坡顶边缘的距离 mm、 ω为最大 转角弧度。
03抗拉主筋所需的滑动处理层的总长度可按下式确定：
μ = ε *Es/ fyk-2La 6-1-9 式中： μ为抗拉主筋所需的滑动处理层总长度、 ε为允许缝隙量 m、 Es为钢筋弹性 模量 kPa、 fyk为钢筋抗拉强度标准值 kPa、 La为锚固段等效自由长度， 2级钢可近似取 10d、 3级钢可近似取 15d。
03) 为使连接处的最大弯矩小于桩身的允许弯矩 M, 宜满足：
a ' n ' fyk ' r≤M 6-1-10
式中： a为抗拉主筋面积、 n为抗拉主筋根数、 fyk为抗拉主筋抗拉标准值、 r为中板 坡顶线半径。
6.2斜桩铰接处理
斜桩铰接可采用直接倾斜连接形式， 如图 2c所示。
本发明提出的新型铰接结构已考虑了斜桩的连接问题， 斜桩连接要点是加长和加 厚桩高侧面的包裹材料，加长包裹材料应伸出混凝土外、加厚包裹材料目的是为了保证 桩高侧面的自由转动量符合最大相对转角需求。斜桩连接方法施工简单，钢筋制作与直 桩情况一样， 可定型生产， 斜桩处理非常方便， 由于长分段结构适用条件是摩擦型桩， 打桩一般按桩顶设计高程控制，割桩头的情况不多， 因此这两种斜桩连接方法都适用于 长分段结构。
6.3新型铰接结构的特点
新型铰接结构在承受轴向拉力时，相比于传统铰接结构具有一定的轴向松弛量，经 分析认为这对长分段结构是有利的。桩顶受拉松弛时会减小温差产生的桩拉力， 当基桩 在受拉最不利状态时， 受拉桩上部没有荷载， 对桩基而言， 此时邻近基桩不会达到最不 利受压状态， 对远处基桩的内力也影响不大， 即桩受拉松弛对桩受拉有利、对桩受压影 响不大。对深水长分段码头， 由于基桩的斜度小、承受的水平力小， 基桩的拉力不大甚 至不会出现拉力， 因此桩顶受拉松弛影响更小。 对纵横梁而言， 当桩受处于拉状态时， 对应的上部没有荷载， 附近梁不会产生最大正弯矩， 而对远处梁的正弯矩影响不大， 综 合分析对正弯矩影响较小；虽然桩受拉松弛会对该处梁的负弯矩产生增大作用，但考虑 到面板可参加抵抗负弯矩以及纵横梁可部分塑性调整的性能，实际调整增大的负弯矩不 会对纵横梁造成较大影响， 如担心梁负弯矩增大的影响， 可适当增加负弯矩配筋量。
新型铰接结构产生相对转角时会使上部结构有所抬高，但由于接触面较小，所以转 动产生的抬高量不大。从平面各桩上看， 这种抬高量是逐渐缓慢变化的， 对结构的影响 很小， 过去大管桩采用铰接连接时也有这种情况， 且抬高量有可能大于新铰接情况， 实 践中也没有发生问题。
新型铰接结构采用了受拉主筋增加滑动处理段的做法，该技术在公路桥梁的预应力 结构中已普遍采用， 是可借鉴的成熟经验。 由于桩内浇筑混凝土深度一般为 2m， 因此 滑动处理段可向桩内更多延伸， 以减小主筋伸入上部混凝土的高度。
由于当铰接桩顶的连接抗弯强度不大于桩身允许弯矩时，桩顶的连接抗弯强度对结 构受力是有利的， 实际上是一种安全预留， 当偶然发生超大水平力或地震时， 桩顶的连 接抗弯强度也会发挥作用， 因此设计桩顶连接处宜具有一定的抗弯能力，但不宜超过桩 身的抗弯强度。
虽然新型铰接结构产生的构顶弯矩远小于传统铰接结构，但也并非理想铰接，设计 宜考虑将桩身的泥下最大弯矩适当增大， 可乘系数 1.1〜1.2。
采用新型铰接结构要求施工安放预制纵横梁时， 不能拆除底部支撑。
新型铰接结构具有以下优点- ①铰接桩工作可靠， 桩顶允许的相对转角较大， 产生的桩顶弯矩一般可控制在小 于桩身允许弯矩范围内， 能满足长分段结构的铰接要求。
②桩承担轴向压力性能可靠， 压力是直接传递于桩顶面上。
③桩内浇筑混凝土主要承担桩拉力， 长分段结构基桩拉力不大， 桩内浇筑的混凝 土深度一般只需满足钢筋锚固及符合构造要求即可。
④ 当采用桩帽时， 由于连接钢筋笼直径较小， 一般可伸入纵横梁结点锚固， 因此 桩帽高度较小， 一般可按构造要求取小值 60cm， 有利于提高施工水位。
⑤桩顶可不必伸入下横梁， 有利于下横梁底钢筋直接从桩顶通过， 方便施工。
⑥长分段结构采用铰接桩更能适应风浪恶劣条件下桩顶难刚接的情况， 更适合用 于外海深水码头情况。
7长分段结构的设计与施工要点
7.1 长分段码头的内力计算方法
长分段结构在面板上的荷载作用下，可按荷载传递到面板、面板传递到纵横梁的模 式计算， 对于纵横梁等高情况， 有条件时宜采用纵横梁作为格型梁， 桩帽或桩顶作为弹 性支座的空间格型梁弹性支座法计算。如按平面梁法计算，若能合理地确定支座弹性系 数等参数， 则无论按 "从纵梁传递到横梁"还是 "从横梁传递到纵梁"计算的结果都是 一致的。但由于平面梁法的支座弹性系数等参数很难准确确定，甚至可能存在较大 ½差， 因此原则上应按照从相对较小梁传递到相对较大梁的模式计算，这样才能保证计算的相 对误差较小。平面梁法的支座弹性系数原理上宜取在最不利码头荷载布置状态下、纵梁 荷载值与考虑空间影响后的支座沉降值之比，这样虽然在非最不利荷载状态下计算结果 不准确， 但由于此时内力不是设计控制内力， 结构也不会发生损坏， 因此计算内力是否 正确问题不大，但能保证在最不利荷载状态下计算结果是准确的，这也符合极限状态设 计原理。根据长分段结构的纵横梁设置情况，;采用平面梁法计算时宜采用 "从纵梁传递 到横梁"的模式为好。纵梁的支座弹性系数取值对荷载作用下的结构内力反应不是很敏 感， 可参照现行高桩码头规范确定。
船舶横向水平荷载可按弹性梁法分配于各个排架上，码头面荷载可通过纵梁支座传 递到各个排架上。这样在每个排架所承受的横向面力（包括水平力、竖向力和横向面上 的弯矩）都可以分解确定。假定所计算的排架处于最不利荷载状态时，一般要求邻近排 架的荷载状态基本相同，这时所计算的排架与邻近排架的变形基本相同，可忽略排架的 差异变形所产生的纵梁传递力，这样就可将所计算的排架简化为平面计算。由于当计算 的排架处于最不利荷载状态时，要求最大荷载作用于该排架上，这时邻近排架上的荷载 只能等于或小于最大荷载， 当邻近排架荷载小于所计算排架荷载时，就会通过纵梁分担 所计算排架的荷载， 因此采用平面排架计算通常是偏安全的。长分段结构的排架受力基 本符合简化为平面排架计算的条件， 因此可釆用平面排架计算。
长分段码头结构的内力计算也可分为施工期和使用期两阶段。施工期的计算与常规 高桩码头一样； 使用期计算可分为： （1)纵向连续梁计算、 （2)纵向水平力及纵向温差作 用下结构的整体计算、 （3)各排架水平力分配系数确定、 （4)横向排架计算。 以下分别介 绍各计算要点：
(1)纵向连续梁计算可按照现行《高桩码头设计与施工规范》执行， 即将荷载转化 为作用于纵梁上的垂直力及纵立面弯矩后， 釆用弹性 （或刚性）支承连续梁法计算。
(2)将荷载按纵向转化为作用于纵梁上的垂直力及弯矩后， 还剩下一个作用在纵梁 轴线上的纵向水平力。 该纵向水平力及纵向温差作用下结构的内力计算可按第 3条所述 的方法确定。计算要点是：①计算温差内力时是取桩泥面高程越低、 m值越高时越安全， 计算荷载产生的内力时则恰好相反。荷载与温差组合时应考虑可能出现的泥面高程高低 值、 m的高低值情况分别进行计算， 取不利情况作为设计值。 ②纵向水平力应考虑船舶 跨越分段平台系缆时， 跨平台对拉系缆力的纵向分力、船舶靠岸撞击力纵向分力、水流 波浪力、 门机刹车力、行使可能撞击挡车板力、地震力、其它可能的纵向荷载以及可能 的组合； 混凝土收缩及气象变化等产生的等效温差可按第 2条所述的方法确定。 ③纵向 地震及门机撞击挡车板等也可按上部结构视为单质点、弹簧刚度根据结构纵向整体刚度 考虑地震提高系数后的单质点振动体系计算。④计算温差桩轴力时， 由于桩顶轴向刚度 的取值对计算结果比较敏感（桩轴力大致与桩顶轴向刚度成正比）， 因此桩轴向刚度宜 釆用实测值。
(3)各排架水平力的分配系数按第 4条所述的方法确定。 计算要点是： 长分段结构 应采用弹性支座连续梁方法确定排架水平力分配， 连续梁的刚度可取上部结构的面板、 纵梁及磨耗层组成整体共同工作的水平抗弯刚度，各支点的弹性系数可釆用排架软件计 算， 即在面板中心处施加水平力， 按水平力与水平位移之比确定。长分段结构的钢管桩 叉桩排架、混凝土叉桩叉桩排架、 以及中间纵向受力桩排架的水平刚度各不同， 宜采用 不同的支座弹性系数计算。其中中间纵向受力桩排架的横向刚度也可偏安全地取零值计 算。可利用高桩码头纵梁计算软件，按弹性支座连续梁计算的支座反力即是各排架分配 的水平力。
(4)横向排架计算的要点是：①在一个码头分段内，要计算边缘两排架、改变桩基 布置的最外边排架以及其它可能起控制内力的排架；②不同的桩基布置要按不同的计算 图式计算；②可不考虑中间段传统铰接结构与两边外段新铰接结构的差异，全部简化为 铰接计算；④纵向布置斜桩的中间区段横向排架计算时还应考虑纵向斜桩在纵向水平力 作用下产生的竖向反力并参与荷载组合，同时应注意校核所有桩竖向反力的合力及合力 矩基本为零。⑤船舶直接作用于排架上的竖向力全部由该排架承担，水平力可在作用点 处施加全部直接力、沿面板轴线近似按均匀分布作用与其它排架传递的合力，两者合力 应等于排架分担的水平力。
7.2 温差变形产生桩轴力的考虑
温差变形产生的轴力在桩身计算中宜全部考虑，但对地基承载力的影响则应根据具 体情况考虑以下几个因素：
①试验提供的桩轴向反力系数是在试验期间短期内多次循环稳定后的反力系数， 而温差变形是一年中缓慢施加的变形， 由于土的变形刚度与加载速度密切相关，实际缓 慢加载的温差变形刚度一般要远小于试验时加载的刚度，因此按试验提供的轴向反力系 数要比实际温差条件下大许多， 实际摩擦桩轴力一般可打折 0.3〜0.5。
②温差变形对土的作用不象荷载那样始终保持恒定值。 对温差变形产生的土摩擦 力而言， 当桩在同方向荷载作用下产生的位移等于温差变形位移后，温差产生的土摩擦 力就消失了，此后桩的极限摩阻力与无温差变形的极限摩阻力基本一样。 由于温差产生 的轴向变形很小， 对以摩擦为主的桩型， 这种温差变形对承载力的影响可以不计， 相当 于土体沉降基本稳定后打桩可不考虑负摩擦力的原理一样；但为安全起见，对非地震情 况可进行温差拉力的抗拔验算。但对于嵌岩桩、锚杆桩等变形敏感的桩型， 则宜考虑温 差压力的影响。
③对叉桩来说， 温差变形是使一根桩轴力增大、 而另一根桩则轴力减少， 叉桩结 点的竖向合力大致抵消，结点产生的竖向变位小，加之高桩码头纵向是比较柔性的结构， 可以不考虑温差对上部结构竖向变形的影响。
④对以摩擦为主的桩型， 控制温差轴力的约束条件主要是地基变形问题。 但目前 港工还没有这方面的经验。考虑到规范要求桩基实际承受的荷载作用标准值不超过地基 承载力的 1/2， 剩余 1/2是作为承载力的安全预留。 建议限制计算温差的轴压力 （比实际 值大） 不超过地基承载力的 1/2， 在此范围内可不考虑温差产生的桩压力对桩承载力的 影响。 在此范围内也不考虑温差产生的上部结构竖向变形问题。
7.3结构及构件设计要点
(1)等效温差设计值按第 2条确定， 温差变形产生的内力分项系数港工规范没有规 定， 考虑到温差变形缓慢， 土有蠕变影响， 温差实际产生内力不会超过计算内力 (尤其 是软土),对码头结构的危害是属于使用耐久性问题，可暂定其分项系数为 1.0，按恒载 (准 永久荷载)考虑。
(2)为减小温差对结构的影响， 宜在每隔 40〜60m解除纵向夹桩的结构跨中， 设置混 凝土后浇跨， 施工方法见 7.4。
(3) 当桩基弯矩对分段长度起控制作用时， 不宜选用过大的桩径。 桩径的选择应考 虑包括桩的稳定、 桩距、 横向夹角等因素综合确定。
(4)暂定设计按温差产生的轴向位移允许值 4~5mm、 温差产生的轴向压力值按承载 力的 50%控制。 按铰接桩计算桩泥下最大弯矩时， 宜根据铰接连接情况乘系数 1.1~1.3。
(5)纵向计算除了按桩顶铰接情况计算外， 还应按桩顶刚接情况计算， 根据刚接计 算的桩顶弯矩确定允许采用传统铰接结构的范围，对按桩顶刚接计算的弯矩大于桩身抗 弯强度的基桩， 应采用降低桩顶弯矩的新型铰接结构。
(6)采用新型铰接结构时， 宜校核桩顶转角的相对转动量， 保证铰接桩桩顶的允许 转动量大于计算的桩顶最大相对转动量；钢筋在接触面处的弹性允许缝隙量应满足桩顶 转动量要求。验算桩顶的转动量时，可考虑受拉主筋在弹性容许缝隙值情况下所产生的 桩顶反弯矩。
(7)纵梁及桩帽设计应考虑纵向水平力整体计算时的桩顶内力以及温差变形计算时 的桩顶内力。
(8) 中间段采用纵向受力斜桩的排架应考虑斜桩由纵向水平力产生的下列作用： ① 横梁的水平方向受力， 可分为： 下横梁水平抗弯连续梁、下横梁支座悬臂于纵梁、上横 梁作为三边约束的板等三个方面。 由于下横梁水平刚度大、所承担的荷载一般大于上横 梁作为板受力所承担的荷载， 因此可偏安全地取下横梁分担荷载系数为 1.0， 上横梁分 担荷载系数为 0.5。 下横梁水平抗弯连续梁计算可将纵横梁交叉点视为弹性铰支座计算 配筋； 下横梁支座悬臂于纵梁可在纵梁附近配置竖向钢筋满足支座反力的悬臂抗弯要 求； 上横梁作为板受力其最大弯矩位于上下横梁连接处， 可在桩每侧 6倍的上横梁宽度 内，布置竖向钢筋以抵抗上横梁作为板所承担的弯矩。上横梁水平方向的抗弯配筋不必 增强 (因有下横梁承担水平力)。 下横梁水平抗剪箍筋、 上下横梁连接箍筋、 下横梁两侧 的水平抗弯钢筋以及纵梁处的悬臂抗弯钢筋均宜通过计算确定。初步分析表明：横梁抵 抗纵向受力斜桩所增加的钢筋用量不多，可在正常配筋范围内满足要求。②横梁的竖向 受力， 应考虑斜桩在水平力作用下产生的竖向反力， 并参与排架计算的荷载组合。
(9)应验算纵向地震水平力作用。 长分段码头虽然采用铰接桩对抗震有些不利， 但 中段可布置较多的纵向叉桩有利抗震。长分段码头的纵向抗震设计验算需要考虑以下两 点： ①实际并非完全铰接， 设计虽然按铰接计算， 但在地震条件下， 桩顶联系钢筋仍会 发挥作用，设计要保证联系钢筋有一定的抗弯强度作为抵抗地震的安全富余，并在桩顶 连接处应有一定的塑性构造要求； ②抗震验算时摩擦桩的抗拔（或抗压）承载力不必考 虑温差引起的桩轴力， 因为温差引起的桩轴力不是始终作用的恒力，对桩极限承载力基 本无影响。
7.4施工要点
(1)施工工序： 打桩一横纵夹桩一浇筑桩帽或下横梁→后浇跨两边加强整体夹桩一 拆除后浇带纵向夹桩一安装预制梁一拆除底支撑及底模板一浇筑非后浇带混凝土一浇 筑后浇跨混凝土—形成整体结构
(2)打桩施工应采取保证措施，要特别注意控制斜桩的方位角、左右摆动角的偏差， 以及相邻直桩的偏差， 确保打桩不发生碰桩并使误差控制在允许范围内。
(3)在安装预制梁时不可拆除桩帽或下横梁支撑， 安装预制梁过程中产生的不平衡 力应由底部支架承担。
(4)后浇跨（见图 26~27) 处理要求如下：
①安装预制纵梁前， 首先应将后浇跨相邻跨加强整体夹桩， 可在已有横向夹桩 083 和纵向夹桩 082的基础上，增设交叉夹桩 081的方法处理;在相邻跨完成加强整体夹桩后， 拆除后浇跨的纵向夹桩 082; 如图 26。
② 吊运安放预制梁顺序， 应先安放非后浇跨梁， 最后安放后浇跨纵梁。 此时安放 后浇跨纵梁由于另一边已对称安放了纵梁， 因此结点受力基本自然平衡、可不必设置后 浇跨支撑。
③后浇跨纵梁搁置端 091应设置滑动垫层 092， 如图 27， 滑动垫层可采用涂油等方 法处理。 设置滑动垫层目的是进一步消除温差变形对结构的影响 （图中 093为浇铸混凝 土、 094为纵梁、 095为桩帽或下横梁、 096为夹桩支撑）。
④浇注非后浇跨混凝土至后浇跨附近可设施工缝位置 097， 如图 27所示。
⑤预制纵梁龄期达 2个月以上后再安装， 宜选择比年平均温度低 10° 左右的季节浇 筑后浇跨混凝土。
长分段码头的施工工艺与常规码头基本相同， 后浇跨处理也非常简便， 设计与施工 是可行的。
8伸缩缝的连接结构
长分段结构伸缩缝的伸缩变形量较大、可达 10cm以上， 需要研究轨道机械与其它 流动机械平稳过渡伸缩缝的连接结构。
8.1 轨道连接结构
由于长分段码头伸缩量较大，如果在伸缩缝处轨道断开，则轨道的最大缝隙不会小 于温度缝的伸缩量， 由于长分段码头的伸缩量较大， 伸缩缝的缝隙一般为 5〜10cm， 不 能满足轨道允许缝隙为 2cm的要求， 因此轨道采用断开形式不能适用于长分段码头。 如 果轨道采用纵向通长焊接， 因轨道日夜温差与码头结构的混凝土截面平均温差相差较 大，轨道产生的相对伸缩量也较大，在长分段码头的伸缩缝处轨道因两端受力不平衡容 易产生纵向移位，容易使轨道一端抵达阻挡结构而产生较大反力；轨道在纵向相对位移 过程中， 因为轨道摩擦力、门机静止自重等产生的摩擦力等对码头伸缩缝也会产生不明 确的纵向力。 本文提出的轨道连接新形式能克服以上缺陷。
本发明提出的温度缝轨道安装示意图参见图 3，轨道工作原理示意图见图 4，轨道连 接示意图见图 5。 轨道连接结构包括跨越伸缩缝的主轨道 （11 ), 附轨道 （16)， 连接片 ( 12), 底板 （13)、 立板 （14)、 压板 （15)、 顶板（18)。 主轨道与附轨道以及附轨道 之间通过连接片连接； 底板、立板、顶板釆用焊接； 压板通过螺栓固定于立板上。 轨道 可沿着底板、立板、压板所限制的区域内纵向滑动。轨道连接处的间隙范围由连接片上 的长形孔（123 )控制（最大缝隙量可控制为 20mm)。底板与预埋螺栓（132)的位置调 整通过底板宽大的半开孔（131 ) 实现。
主轨道与附轨道均为 "工"字型结构参见图 6〜图 11，主轨道（11 )跨越伸缩缝（19)， 长度宜取 60〜80cm， 具有一定的长度有利于适应两平台发生少量错位。 加焊钢板两端 外留有原轨道一定长度， 用于搁置在底板 （13 )上伸缩。 附轨道长度约 20cm。 在主轨 道与附轨道的两端肋板上各有一圆孔（1113)。 连接片 （12)两端各有一长形孔（123 ) 参见图 9。 主轨道与附轨道以及附轨道之间通过连接片相互串联连接。 所述的连接采用 螺栓穿过圆孔（1113 )及长形孔 （123), 螺栓与连接片长形孔 （123 )连接后有纵向间 隙，所述纵向间隙用于控制轨道间的伸缩缝隙量。所述主轨道与附轨道的轨道顶面（ 111 ) 两端部设置有与纵向轴线约成 30°主斜角（1111 ) (为简明起见附轨道未图出端部斜角）； 所述主斜角（1111 )的锐角端设有倒角（1112)，倒角与纵向轴线约成 5°、切削深度约 4〜 5mm。这样轨道机械能平稳连续地渡过轨道缝隙而不会碰到锐角端，锐角尖端即使发生 压屈对使用也无影响。所述主轨道底面（112)下可焊接钢板（17)， 以增强主轨道的抗 弯能力。 附轨道的数量根据伸缩缝的最大伸缩量确定。 主轨道可在轨道底面 （112)下 加焊钢板（17)见图 7〜8， 以增强轨道的抗弯能力， 主轨道每端用于搁置在底板的长度 可取"总伸缩量 /2+允许误差 +最小搁置长度 +斜顶面产生的底板缩量"。通孔 123净高、通 孔 1113及连接螺栓直径宜取 20mm左右， 螺帽安装好后可用电焊固定， 以防松动脱落。
参见图 3、图 12、图 13，底板（13 )上设有两个立板（14)，立板的内侧设有压板（ 15), 立板和压板上设有圆孔 （19)和 （20)， 立板和压板通过螺栓穿过圆孔 （19)和 （20) 固定， 使主轨道与附轨道被限制在底板、立板及压板所围成的区域内滑行， 轨道与限制 区域的间隙控制在 l〜2mm之间。在所述立扳（14)上焊接顶板（18)， 以防止压板（15 ) 跳出并形成码头面。
所述的底板（13 )设有半开孔（131 )。 可在预埋螺栓（132)上调整底板位置， 所 述的预埋螺栓 （132)在铺设轨道前预埋于现浇混凝土中。
现场安装时， 伸缩缝两侧的底板间距应根据最大缝隙量及安装时的温度由计算确 定。 使用后应进行观测， 发现问题应及时进行拆装调整。
该连接结构加工容易、安装和维护方便、能满足长分段码头的伸缩缝要求， 轮子跨 越缝隙时在横断面上是无缝连续过渡， 门机工作平稳，能适应两段平台在使用过程中发 生少量空间错位。 伸缩缝轨道完全不传递纵向力。
8.2无轨流动机械温度伸缩缝形式
长分段码头伸缩缝的伸缩量较大 （一般 5〜20cm)， 传统的码头伸缩缝形式已不能 适应车流平稳行驶的要求， 桥梁已有许多伸缩缝形式（如齿形伸缩缝等）， 可移植采用。 但桥梁的伸缩缝形式比较复杂， 本文提供一种简单伸缩缝形式， 可供车流量不大、车速 较低的码头选用。
伸缩缝形式平面俯视图见图 14, 立面图见图 15:
跨越伸缩缝（300)的上钢板（201 )的一端搁在下钢板（202)上滑动，上钢板（201 ) 的另一端有圆孔（203)， 圆孔定位于预买埋螺栓（206)上。 下钢板粘贴于混凝土表面。 上钢板长度可取最大伸缩量加 40cm左右， 厚度可按计算确定， 但不宜小于 20mm。 上钢 板的圆孔直径不宜小于 25mm， 上部螺帽位置的直径应大于螺帽直径， 见图 16的上钢板 放大孔（203)， 使安装的螺帽低于上钢板表面。
下钢板（202)应略为倾斜安装（见图 15)， 其两端高差可取上钢板（201 )厚度的 2倍左右。上钢板搁在下钢板的滑动端宜削成约 6〜8°左右的小斜角（204)， 使流动机械 通过伸缩缝时跳动较小。
安装要求在伸缩量约为一半时上钢板处于水平状态， 应通过施工期间温度计算确 定安装上下钢板及预埋螺栓的安装位置。
本伸缩缝不会受到码头碎撒物堵塞， 工作可靠， 维护方便， 拆卸容易。 码头伸缩 缝在连接轨道 （400) 旁有一段构造空隙， 可采用这种形式加长钢板覆盖， 当轨道需要 调整时， 可打开该覆盖钢板进行轨道维护。

Claims

权 利 要 求
1、离岸高桩码头长分段结构， 其特征在于， 所述结构的分段长度不小 于 120m; 所述长分段结构位于温差纵向位移零线 25m以外的叉桩均采用 小横向夹角布置;位于温差纵向位移零线 25m以内的叉桩沿纵向受力布置; 所述长分段结构的桩基桩顶采用铰接形式； 所述长分段结构位于分段两边 缘的第一跨排架间距小于内跨排架间距； 所述码头伸缩缝处的轨道衔接采 用多小段间隙不超过 20mm的轨道连接结构。
2、根据权利要求 1所述的离岸高桩码头长分段结构， 其特征在于， 位 于距温差纵向位移零线 25m以外的叉桩均采用小横向夹角， 其角度根据桩 基布置及打桩偏差情况通过计算确定，一般在 10〜18°范围内； 当横向夹角 较大需要减小横向夹角时， 可采取下列措施： ①与所述叉桩可能碰桩的相 邻直桩改为斜度不大于 20: 1 的反向纵向斜桩； ②所述叉桩桩顶与可能碰 桩的相邻直桩桩顶采用偏离排架轴线约 10cm左右错开布置。
3、根据权利要求 1所述的离岸高桩码头长分段结构， 其特征在于， 位 于温差纵向位移零线 25m以内的叉桩沿纵向受力布置， 所述叉桩的纵向夹 角小于 45°， 采用混凝土桩， 其倾斜度可小于位于温差纵向位移零线 25m 以外的混凝土叉桩， 所需的最小桩数及倾斜度应根据码头分段所承受的纵 向水平力及抗震要求确定。
4、 根据权利要求 2所述的的离岸高桩码头长分段结构， 其特征在于， 当位于温差纵向位移零线 25m以外的叉桩， 全部采用混凝土桩不能满足抵 抗横向水平力要求时， 可将分段两边缘若干排架区域的叉桩换成倾斜度较 大的钢管桩， 钢管桩的尺寸及数量由计算确定。
5、根据权利要求 1所述的离岸高桩码头长分段结构， 其特征在于， 所 述桩顶铰接形式可分区段采用不同的铰接连接结构： 对桩顶弯矩小于桩身 强度的位于中间区段的基桩， 桩顶铰接可采用常规铰接结构'； 而对桩顶弯 矩可能大于桩身强度的位于分段边缘区域的基桩， 桩顶铰接可采用降低桩 顶弯矩的铰接结构。
6、根据权利要求 1所述的离岸高桩码头长分段结构， 其特征在于， 所 述的长分段结构位于分段两边缘的第一跨排架间距小于内跨排架间距， 可 按照边缘排架的基桩、 纵梁、 横梁的控制内力接近中间排架控制内力的要 求， 确定第一跨排架间距。
7、根据权利要求 1所述的离岸高桩码头长分段结构， 其特征在于， 纵 梁施工安装前每隔 40〜60米应拆除一跨纵向夹桩，以完全释放纵向夹桩力、 并在此设置后浇跨， 以降低长分段码头纵向混凝土伸缩产生的内力。
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