CN110106971B - Prefabricated assembly beam column system for enhancing structural earthquake resistance and collapse resistance - Google Patents
Prefabricated assembly beam column system for enhancing structural earthquake resistance and collapse resistance Download PDFInfo
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- E04B1/18—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons
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- E04B1/18—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons
- E04B1/20—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons the supporting parts consisting of concrete, e.g. reinforced concrete, or other stonelike material
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- E04H9/02—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
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Abstract
The invention belongs to the technical field of building structures, and discloses a prefabricated assembly beam-column system for enhancing the earthquake resistance and collapse resistance of a structure; comprises a prefabricated reinforced concrete column; the prefabricated reinforced concrete column consists of three sections, wherein two ends of the prefabricated reinforced concrete column are respectively provided with a section of reinforced concrete column body, the middle part of the prefabricated reinforced concrete column body is provided with a section of reinforced concrete core column, and the replaceable parts are assembled at the periphery of the core column and are detachably connected with an outer casing pipe arranged on the prefabricated reinforced concrete column body; the prestressed tie bars penetrate through the prefabricated reinforced concrete beams and the prefabricated reinforced concrete columns without being bonded and are anchored at the corners of the outer frame. The invention can obviously improve the energy consumption capability of the plastic hinge at the end part of the column and delay the rigidity degradation rate of the plastic hinge; plastic deformation is concentrated on the replaceable component group, so that the repair work after damage is reduced; the catenary mechanism of the prestressed lacing bar reinforced beam is used as a second defense line to improve the collapse resistance of the fabricated structure.
Description
Technical Field
The invention belongs to the technical field of building structures, and particularly relates to a prefabricated beam-column system for enhancing the earthquake resistance and collapse resistance of a structure.
Background
Currently, the current state of the art commonly used in the industry is such that: in earthquake disasters of past times, the reinforced concrete frame is mostly in a 'strong beam and weak beam' damage form with plastic hinges at the column end, and a 'strong beam and weak beam' failure mode expected by building earthquake-resistant design specifications rarely occurs. Many experts have studied the phenomenon, point out that a plurality of beneficial factors such as floor reinforcement, beam-end reinforcing bar super-match enable beam-end bending resistance bearing capacity to improve a lot, and reinforced concrete column atress is comparatively unfavorable, therefore "strong column weak beam" failure mode is difficult to appear. If a 'strong column and weak beam' failure mode is strictly realized in the reinforced concrete frame, namely, the reinforced concrete frame column is ensured to have high bearing reliability and high ductility, the column must be designed to be very conservative, and the consumption of concrete and reinforced steel bar materials can be greatly improved. Many researches also show that the eccentricity of the section of the reinforced concrete column can be randomly changed due to the random uncertainty of horizontal action (wind and earthquake), and the bearing capacity reliability of the reinforced concrete large-bias column designed according to the existing method can be greatly fluctuated and changed after the change effect of the resistance along with the random eccentricity is considered. In some cases, the reliability of reinforced concrete columns is highly estimated and the design is biased towards insecurity. The reliability of the reinforced concrete column designed according to the small bias voltage under the random eccentricity is obviously higher than that of the reinforced concrete column designed according to the large bias voltage (the reliability of the design target of the reinforced concrete column with the small bias voltage is high), and the fluctuation range of the reliability is small and is not greatly different from the reliability of the design target.
With continuous progress of basic theory and technology and popularization and application of high-performance materials, people have higher and higher requirements on the performance of the structure, and on one hand, the structure is gradually changed from a limit state design to a recoverable function design so as to reduce the loss to the minimum; on the other hand, since a building structure may face threats from different disasters during the whole life cycle of use, it is also a development direction of civil engineering in the future to improve the multi-disaster defense capability of the structure. For the reinforced concrete frame structure which is most widely applied in China, earthquakes and continuous collapse are the most important disaster sources in the using process of the reinforced concrete frame structure. Therefore, by arranging the replaceable parts at the key parts of the structural system which are easy to generate plastic deformation, high-ductility materials and novel energy-consuming materials can be used in the structural system, and quick repair and replacement of damaged parts can be realized. The bearing capacity of the component is basically consistent with that of the original part through design, and the design requirement of the normal use limit state is met. When the structure bears stronger horizontal action, the damaged part is mainly concentrated at the replaceable component, so that the excellent performance of the replaceable component material can be utilized to effectively consume energy, the damaged component can be quickly replaced, and the normal use function of the structure can be recovered as soon as possible. And as the second line of defence of structure, promote the anti progressive collapse performance of structure, avoid causing with the initial structure part that destroys disproportionately and the whole collapses, also has extremely important realistic meaning. Most of the former functional restorable structures and multi-disaster defense structures proposed by most scholars are improved aiming at the frame beams, and the improvement performance of the form can be fully exerted in a pure frame structure without considering cast-in-place floor slabs and infilled walls. However, when considering the constraint effect of the cast-in-place floor slab and the infilled wall on the frame beam, the improvement of the deformation capability and the restorable function of the structure can be greatly reduced.
In summary, the problems of the prior art are as follows: under the action of a large horizontal load, plastic hinges appear at the upper column end and the lower column end of a node area of most frame structures, and the frame structures are difficult to repair after being damaged; the bearing reliability of the reinforced concrete column in the prior art under the action of horizontal load (wind or earthquake) is lower than the expected level; the assembled structure has weaker anti-collapse capability, and the traditional anti-continuous collapse design ensures that the frame structure is possibly damaged in a form of 'strong beam and weak column' under the action of an earthquake due to the increase of longitudinal ribs in the beam, so that the anti-earthquake is more unfavorable.
The difficulty and significance for solving the technical problems are as follows: because the beam hinge mechanism is difficult to realize after the influence of a floor slab, a filler wall and the like is considered in the frame structure, and after plastic hinge occurs at the column end of a common reinforced concrete column, the steel bar is yielded, the concrete is crushed, and the structure loses the capacity of continuous bearing, so that the frame structure is possibly subjected to a layer yield mechanism or integral collapse. In view of the above disadvantages, most of the previous improvement measures proposed by scholars are developed for the frame beam, and the influence of the floor slab, the infilled wall and the like is generally not considered when performing experimental and theoretical analysis, so that the improvement measures are difficult to fully exert the improvement effect after considering the constraint effect of the cast-in-place floor slab, the infilled wall and the like on the frame beam. Therefore, how to ensure that the structure has strong energy consumption capability and has the capability of continuously bearing after partial materials are yielded is a challenging problem.
Because the bearing capacity of the reinforced concrete column is designed according to the stress form of large bias voltage in the existing earthquake-proof standard design method, the bearing capacity reliability of the reinforced concrete column with large bias voltage can fluctuate greatly under the action of horizontal load (wind or earthquake). In some design situations, the reliability of reinforced concrete columns is heavily overestimated and the design is biased towards insecurity. Therefore, how to guide the frame columns to form a stress state with high bearing reliability, thereby improving the bearing performance of the structure, is another problem to be solved.
The assembly type structure forms a whole through an assembling technology, the collapse resistance of the assembly type structure is weaker than that of a cast-in-place structure due to the weak connection, and in addition, when the cast-in-place or assembly type frame structure constructed according to the prior art suffers from rare earthquakes or accidents, due to the lack of a spare load path, the continuous collapse is very easy to occur due to local damage. Such collapse incidents occur frequently throughout the world, such as collapse of most of the frame structure in the Wenchuan earthquake, collapse of the london Ponan Point apartments due to gas explosions, collapse of the U.S. Alfred P.Murrah Federal office building due to car bombs, and the like. Therefore, how to improve the collapse resistance of the fabricated structure and coordinate with the seismic performance of the structure is also a problem that needs to be studied urgently.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a prefabricated beam-column system for enhancing the earthquake resistance and collapse resistance of a structure.
The invention is realized in this way, a prefabricated assembly beam-column system for enhancing the earthquake resistance and collapse resistance of a structure, which comprises: at least one prefabricated reinforced concrete column and at least one prefabricated reinforced concrete beam;
the prefabricated reinforced concrete column consists of three sections, wherein two ends of the prefabricated reinforced concrete column are respectively provided with a section of reinforced concrete column body, and the middle part of the prefabricated reinforced concrete column is provided with a section of reinforced concrete core column; the section size of the reinforced concrete core column is smaller than that of the reinforced concrete column body; the prefabricated reinforced concrete columns on the upper layer and the lower layer of the structure are connected in the middle of the floor height;
the reinforced concrete core column is externally wrapped with a core column steel sleeve, and two ends of the core column steel sleeve extend into the prefabricated reinforced concrete column body; the outer casing comprises an upper outer casing and a lower outer casing, the upper outer casing is wrapped on the upper reinforced concrete column body, the lower outer casing is wrapped on the lower reinforced concrete column body, and the lower end of the upper outer casing and the upper end of the lower outer casing extend out of the reinforced concrete column body;
the replaceable parts are assembled on the periphery of the reinforced concrete core column; each replaceable component group comprises at least two pairs of replaceable components; each pair of replaceable parts comprises an inner replaceable part and an outer replaceable part, and the inner replaceable part and the outer replaceable part are both guard plates.
Furthermore, the upper outer casing pipe and the upper end of the core column steel sleeve are fixed on the upper prefabricated reinforced concrete column body through a split screw; the lower outer casing sleeve and the lower end of the core column steel sleeve are fixed on the lower prefabricated reinforced concrete column body through the split screw rods.
Further, the prefabricated assembly beam column system of reinforcing structure antidetonation and anti-collapse performance still includes:
the steel sleeve comprises a core area steel sleeve, wherein the middle of the core area steel sleeve is grooved and arranged in the core area of the beam column node, and two ends of the core area steel sleeve extend out of the core area by a certain length.
Furthermore, the lower end of an upper outer casing pipe extending out of the body of the reinforced concrete column is detachably connected with the upper end of the upper replaceable component group, and the lower end of the upper replaceable component group is detachably connected with the upper end of a steel sleeve in the core area; the lower extreme of nuclear core district steel bushing and the upper end of lower part removable parts group can be dismantled and be connected, and the lower extreme of lower part removable parts group can be dismantled with the upper end of outsourcing sleeve pipe and be connected down.
Further, the prefabricated assembly beam column system of reinforcing structure antidetonation and anti-collapse performance still includes: the prestressed tie bar is arranged on the neutral surface of the prefabricated reinforced concrete beam, a reserved tie bar hole channel is formed in the prefabricated reinforced concrete beam, and a tie bar sleeve is arranged in a node core area; the axis of the reserved drawknot rib hole and the axis of the drawknot rib sleeve are superposed with the axis of the prestressed drawknot rib, the drawknot rib sleeve passes through the slot of the steel sleeve in the core area and is connected with the reserved drawknot rib hole in the precast reinforced concrete beam, and the inner diameter of the drawknot rib sleeve is larger than the nominal diameter of the prestressed drawknot rib; the prestressed tension bonding ribs penetrate through the pore passages without bonding and are connected with the prefabricated reinforced concrete beams and the prefabricated reinforced concrete columns through the sleeves, and the prestressed tension bonding ribs are anchored at the corners of the outer frame.
Furthermore, the lower end of an upper outer casing pipe extending out of the upper prefabricated reinforced concrete column body and the upper end of a core region steel sleeve extending out of the node core region are arranged between the upper inner side replaceable component and the upper outer side replaceable component and are detachably connected through a high-strength bolt; the upper end of the lower outer casing pipe extending out of the lower reinforced concrete column body and the lower end of the core area steel sleeve extending out of the core area of the node are arranged between the lower-part inner side replaceable component and the outer side replaceable component, and the connection can be disassembled through the high-strength bolt.
Further, the prefabricated reinforced concrete column also comprises longitudinal steel bars and stirrups bound on the longitudinal steel bars; the longitudinal steel bars comprise longitudinal steel bars arranged in the reinforced concrete core column and longitudinal steel bars arranged in the reinforced concrete column body; and hoops are bound on all longitudinal steel bars arranged in the reinforced concrete column and the core column. And two ends of the longitudinal steel bar in the core column extend into the reinforced concrete column body.
Further, be equipped with the roof beam in the precast reinforced concrete roof beam and indulge the muscle, indulge the muscle on the steel casing pipe of nuclear zone and in the precast beam and correspond and be equipped with the hole, the roof beam is indulged the muscle and is extended the hole after-fixing on the steel casing pipe of nuclear zone.
Further, the prefabricated assembly beam column system of reinforcing structure antidetonation and collapse resistance still include with the roof beam is indulged muscle complex straight thread sleeve, the tip extension of muscle is indulged to the roof beam is passed behind the hole, inboard cuts, the end tapping, with straight thread sleeve links to each other and fixes at nuclear core area steel casing inboard.
Another object of the present invention is to provide a reinforced concrete frame using the prefabricated assembled beam-column system for enhancing the earthquake resistance and collapse resistance of the structure.
The advantages and positive effects of the invention are illustrated by theoretical analysis in combination with numerical simulations.
A typical common reinforced concrete column section model is built by adopting section analysis software XTRACT, and then a novel column section model provided by the invention is built by the principle that the axial compression strength is equal, as shown in figure 11. The cross-sectional analysis was performed on each of the two cross-sectional materials to obtain axial force-bending moment curves (N-M curves) of the two cross-sectional materials, and the comparison results are shown in fig. 12. It can be seen that, although the limited compressive bearing capacity of the column is consistent with that of the column when the axis is pressed down, the limited flexural bearing capacity of the column is greatly different from that of the column, and the limited flexural bearing capacity of the section of the novel column is increased by 44% compared with that of the common reinforced concrete column. Moreover, since the tensile strength of concrete is only 1/10 times the compressive strength, the axial tension or eccentric tension bearing capacity of the common reinforced concrete column is low. As can be seen from the N-M curve of the novel column, the novel column still has higher bearing capacity under the condition of tension; and the tensile bearing capacity is improved by 134 percent compared with the common reinforced concrete when the axis is pulled down.
The experiment numerical simulation competition is organized by the anti-collapse professional committee of earthquake-resistant disaster-prevention division building structure of the Chinese architecture society in 2011-2012 and the Qinghua university, finite element simulation is carried out on a group of reinforced concrete column experiment models disclosed by the invention, experiment data can be downloaded from related websites [ http:// www.collapse-prediction.
A Fiber model of finite element software ABAQUS is adopted and a material subprogram PQ-Fiber provided by professor Pengpo of Qinghua university is called to simulate a test model, the numerical simulation result is well matched with the test result, and the method can be referred to in a reference [ Zhonhao, RC frame strong column and weak beam reliability design improvement and verification considering the random characteristic of the eccentric distance of a column [ D ]. Changshi university.2017 ]. And then, according to the principle that the axial compression strength is equal, the reinforced concrete column in the test is improved into the novel column structural form provided by the invention, a finite element model is established by adopting a multi-scale method, and the analysis result is shown in figure 14. It can be seen that, under the principle that the compressive strength of the axis of the novel column is equal, the horizontal bearing capacity is greatly improved, and the dissipated energy (the area enclosed by the hysteresis curve) is correspondingly increased more.
Due to the constitutive parameters of the material in the actual engineering (peak strength f of concrete)cPeak compressive strain epsilon0Ultimate compressive strain epsiloncuYield strength f of steel bar, steel plate, low yield point steelHRB400、fQ345、fLP160) Has random variability and the statistical parameters are shown in the table 1, thereby causing the resistance of the structure to have large variability. The parameter lambda (lambda is equal to epsilon) is counted by collecting the test data of 88 groups of concrete in domestic and foreign documentscu/ε0) The mean value of lambda of about 1.64 (value of 1.65 in the concrete structure design specification) was obtained. Therefore, the ultimate compressive strain ε in the analysiscuTemporarily taken as the peak compressive strain epsilon01.64 times. In order to study the influence of the variation of the constitutive parameters of the material on the resistance of the common reinforced concrete column and the novel column, a uniform design method is adopted, the peak strength and the peak compressive strain of the concrete and the yield strengths of the steel bar, the steel plate and the low-yield-point steel are taken as random variables, and 37 uniform sample points in the actual space are obtained, as shown in table 2.
TABLE 1 statistical parameters of random variables
Standard value | Mean value of | Standard deviation of | κ | δ | |
fLP160 | 160 | 182.88 | 13.16736 | 1.143 | 0.072 |
fQ345 | 345 | 372.6 | 29.808 | 1.080 | 0.080 |
|
400 | 456 | 31.92 | 1.140 | 0.070 |
fc | 20.1 | 28.341 | 5.38479 | 1.410 | 0.190 |
ε0 | 0.002 | 0.0022 | 0.000308 | 1.100 | 0.140 |
TABLE 2 actual spatial sample points
Similarly, the cross-section analysis software XTRACT is adopted to respectively establish the common reinforced concrete column shown in FIG. 11 and the novel column of the invention, and the common reinforced concrete column and the novel column meet the principle that the axial compression strength is equal under the standard material strength. Given the equivalent axial compression ratio of 0.4, the variability of the resistance (bending moment) at the above 37 sample points was analyzed for both sections, and the results are shown in fig. 15. The mean value and the variability of the two are respectively counted, and the result shows that: the average resistance value of the section of the common reinforced concrete column is 222.8kN.m, and the coefficient of variation is 0.202; the mean value of the resistance of the section of the novel column is 304.0kN.m, and the coefficient of variation is 0.108. Therefore, under the same axial compression ratio, the resistance of the section of the novel column under each sample point is larger than that of the section of the common reinforced concrete column, and the variability of the section of the novel column is reduced by about 50 percent compared with that of the section of the common reinforced concrete column.
Further, a single-layer single-span frame model containing novel columns and a conventional reinforced concrete frame model are respectively designed according to the principle that the axial compression strength is equal, the action of the floor slab is considered, and the prestressed tie bars are not arranged. The simulations were performed using the finite element software ABAQUS and invoking the material subroutine PQ-Fiber, and the analysis results are shown in FIGS. 16-17. Due to the reasons of damage accumulation of concrete and the like, the hysteresis curve of the conventional reinforced concrete frame is in an obvious pinching characteristic, while the hysteresis curve of the novel frame is in a fusiform shape, so that the hysteresis loop is fuller. Further analysis shows that the total energy dissipated by the conventional frame and the novel frame is respectively about 261037kN.mm and 579479kN.mm, and the energy consumption capacity of the novel frame is about 2.22 times of that of the conventional frame. The equivalent viscous damping ratio of contrast between them can be seen, after the structure got into the yield stage, because novel frame mainly carries out the power consumption by low yield point steel sheet (removable steel sheet), the power consumption ability is more superior than ordinary reinforcing bar, and equivalent viscous damping ratio increases the range and is bigger, and the structure power consumption ability is corresponding to be improved by a wide margin. FIG. 16 hysteresis curves for a conventional reinforced concrete frame and the novel frame of the present invention; FIG. 17 is a graph showing equivalent viscous damping ratio of a conventional reinforced concrete frame and the novel frame of the present invention.
Under the action of horizontal earthquake, the hinge of the frame structure column is mostly concentrated at the column end of the upper part and the lower part of the node. According to the invention, the concrete-filled steel tube core column and the replaceable component group which are formed by combining the core column steel sleeve and the reinforced concrete core column are arranged at the upper and lower column ends of the node area, and the separated concrete-filled steel tube core column and the replaceable component group can improve the energy consumption capability of the plastic hinge at the column end part and delay the rigidity degradation rate of the plastic hinge on one hand; on the other hand, plastic deformation is concentrated on the replaceable component group, the replaceable component group can be directly replaced after being damaged, and other parts of the structure still keep elasticity, so that the repair work after being damaged is reduced. And because the core column is not damaged, the structure still has larger capacity of continuously bearing after the replaceable component yields, and the structure is prevented from collapsing.
Go up the sheathed tube lower extreme of outsourcing and the upper end and the corresponding removable part group of core region steel casing can dismantle to be connected (if can dismantle the connection through high strength bolt), the sheathed tube upper end of outsourcing down and the lower extreme and the corresponding removable part group of core region steel casing can dismantle to be connected (if can dismantle the connection through high strength bolt), both convenient equipment is favorable to again can dismantle removable part and change fast after impaired. And the improvement position is positioned at the column end, so that the improvement position is not influenced by other factors such as a floor slab, a filler wall and the like, and the improvement effect is easily ensured.
According to the invention, the concrete-filled steel tube core column and the replaceable component are arranged at the failure positions of the upper column end and the lower column end of the node area, under the combined action of vertical load and horizontal load, the concrete-filled steel tube core column bears most of axial pressure and a small part of bending moment, and the replaceable component bears most of bending moment and a small part of axial force. Under the action of a horizontal load lower than a design value (such as during normal use), the reinforced concrete column is in an elastic stress state; under the action of a horizontal load equivalent to a design value, certain plastic deformation occurs to a replaceable part of the reinforced concrete column, and the steel pipe concrete core column still keeps an elastic stress state; under the action of horizontal load greatly exceeding a design value (rarely occurring earthquake), the replaceable part of the reinforced concrete column can generate serious plastic deformation, the structural damage is mainly concentrated on the replaceable part with stronger energy consumption performance, the steel pipe concrete core column can only generate a small amount of damage, and the integral failure of the column is effectively avoided; when the replaceable component is damaged, the replaceable component can be replaced only by loosening the high-strength bolts at the upper end and the lower end of the replaceable component.
Because the tie bar is arranged on the neutral surface of the beam, the anti-bending bearing capacity of the beam is improved slightly, and the defect that the structure anti-seismic capacity is weakened due to more bearing capacity of the reinforcing beam in the traditional anti-continuous collapse design is overcome. When the earthquake action is too large or the risk of collapse of a local structure or an integral structure is encountered, if the bearing capacity of a beam mechanism provided by the longitudinal steel bars in the precast reinforced concrete beam is insufficient, the prestressed tie bars further prevent the structure from being damaged through the catenary effect, the risk of collapse of the structure under the earthquake or accident condition is reduced, and the safety of the structure is improved.
Due to random uncertainty of horizontal action (wind and earthquake), the eccentricity of the section of the reinforced concrete column also changes randomly, when the axial tension generated by the horizontal action is large, the frame column may be broken by bias pulling, and the tensile bearing capacity of the common reinforced concrete column is low. Therefore, when the change effect of the resistance along with the random eccentricity is considered, the bearing capacity reliability of the reinforced concrete large-bias column designed according to the existing method can have large fluctuation change. In some cases, the reliability of reinforced concrete columns is highly estimated and the design is biased towards insecurity. The resistance variability of the novel column is small, and the fluctuation range of the reliability of the column under random eccentricity is correspondingly reduced, so that the reliability of the novel column is higher than that of a common reinforced concrete column designed under a large bias stress state, the purpose of high bearing reliability is favorably achieved, and the reliability of the structure under a designed horizontal load is improved.
The invention solves the problem of rigidity mutation at the connecting part by the constraint effect of arranging the outer casing pipe and the core column steel sleeve, and ensures that the reinforced concrete core column is not damaged due to the reinforcement of the core column steel sleeve, so that the influence of the replaceable component on the structural performance is in a controllable range. Meanwhile, the core region steel sleeve and the core column steel sleeve restrain the concrete in the node core region, so that the shearing resistance of the node region can be effectively improved. The invention has stronger applicability, can be conveniently applied to nodes, edge nodes, corner nodes and top-level nodes in a frame structure, has higher assembly degree and less cast-in-place workload. The bearing capacity robustness and the function recoverability of the structure under the action of the earthquake and the continuous collapse prevention performance under the action of the accidental load are integrated, so that the function recoverability after the earthquake is realized and the continuous collapse prevention performance is realized.
Drawings
FIG. 1 is a schematic cross-sectional view of a prefabricated assembled beam-column system for enhancing the seismic and collapse resistance of a structure provided by an embodiment of the invention;
FIG. 2 is a schematic cross-sectional view of a prefabricated concrete frame for enhancing seismic and collapse resistance of a structure according to an embodiment of the present invention;
FIG. 3 is a schematic structural diagram of an outer casing according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of an embodiment of an inside and outside replaceable part configuration according to the present invention;
FIG. 5 is a schematic illustration of a steel casing structure in the core region according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a core column steel sleeve structure according to an embodiment of the invention;
FIG. 7 is a schematic diagram illustrating an assembly of the upper and lower outer casings, the steel casing in the core area, and the inner and outer replaceable parts according to an embodiment of the present invention;
FIG. 8 is a schematic structural view of a prefabricated reinforced concrete column according to an embodiment of the present invention;
fig. 9 is a schematic structural view of a precast reinforced concrete beam according to an embodiment of the present invention;
FIG. 10 is a schematic structural view of a prefabricated assembled beam-column system for enhancing the seismic and collapse resistance of a structure provided by an embodiment of the present invention;
in the figure: 1. prefabricating a reinforced concrete column body; 2. prefabricating a reinforced concrete beam; 3. a reinforced concrete core column; 4. an outer casing pipe is arranged; 5. a lower outer casing pipe; 6. steel casing in the core area; 7. core column steel sleeve; 8. an upper outer replaceable member; 9. an upper inner replaceable component; 10. a lower outer replaceable member; 11. a lower inner side replaceable part; 12. a first longitudinal reinforcement; 13. a first stirrup; 14. a second longitudinal reinforcement; 15. a second stirrup; 16. a third longitudinal reinforcement; 17. a third stirrup; 18. oppositely pulling the screw rod; 19. a high-strength bolt; 20. a straight threaded sleeve; 21. a prestressed lacing wire; 22. reserving a tie bar pore channel; 23. and (5) stretching the rib sleeve.
FIG. 11 is a cross-sectional model view of the novel column provided by an embodiment of the present invention.
FIG. 12 is a graph comparing N-M curves for two cross-sections provided by an embodiment of the present invention.
Fig. 13 is a graph of pseudo-static test information of a general reinforced concrete column according to an embodiment of the present invention.
Fig. 14 is a graph showing hysteresis curves of a general reinforced concrete column according to an embodiment of the present invention and a novel column according to the present invention.
FIG. 15 is a graph comparing resistance of two types of column sections at various sample points provided by examples of the present invention.
Fig. 16 is a graph showing hysteresis curves of a conventional reinforced concrete frame and the novel frame according to the embodiment of the present invention.
FIG. 17 is a graph of equivalent viscous damping ratio of a conventional reinforced concrete frame and the novel frame of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Aiming at the problems that the bearing reliability of the reinforced concrete column in the prior art (wind or earthquake) is lower than the expected level under the action of horizontal load and the reinforced concrete column is difficult to repair after being damaged; the collapse resistance of the fabricated structure is poor. The invention applies the novel column which can effectively dissipate horizontal input energy by utilizing the ductile material and realize high bearing reliability to the beam-column node, improves the structure of the beam-column node, strengthens the second defense line of the structure and improves the continuous collapse resistance of the structure. The requirements of simple structure, convenient construction, economy, reasonableness, safety, reliability and easy replacement after damage are met.
The following detailed description of the principles of the invention is provided in connection with the accompanying drawings.
As shown in fig. 1 to 9, the prefabricated assembled beam-column system for enhancing the earthquake resistance and collapse resistance of the structure provided by the embodiment of the invention comprises: the prefabricated reinforced concrete column comprises a prefabricated reinforced concrete column body 1, a prefabricated reinforced concrete beam 2, a reinforced concrete core column 3, an upper outer casing 4, a lower outer casing 5, a core region steel casing 6, a core column steel casing 7, an upper outer side replaceable part 8, an upper inner side replaceable part 9, a lower outer side replaceable part 10, a lower inner side replaceable part 11, a first longitudinal steel bar 12, a first stirrup 13, a second longitudinal steel bar 14, a second stirrup 15, a third longitudinal steel bar 16, a third stirrup 17, a split screw 18, a high-strength bolt 19, a straight thread sleeve 20, a prestress lacing bar 21, a reserved lacing bar hole 22 and a lacing bar casing 23.
The prefabricated reinforced concrete column comprises at least one prefabricated reinforced concrete column and at least one prefabricated reinforced concrete beam 2, the prefabricated reinforced concrete column is composed of three sections, two ends of the prefabricated reinforced concrete column are respectively provided with a section of reinforced concrete column body 1, the middle of the prefabricated reinforced concrete column body is provided with a section of reinforced concrete core column 3, and the section size of the reinforced concrete core column 3 is smaller than that of the reinforced concrete column body 1. The prefabricated reinforced concrete columns on the upper layer and the lower layer of the structure are connected in the middle of the floor height;
the prefabricated reinforced concrete column still includes: the core column steel sleeve 7 is wrapped outside the reinforced concrete core column 3, and two ends of the core column steel sleeve 7 extend into the prefabricated reinforced concrete column body 1.
The outer casing comprises an upper outer casing 4 and a lower outer casing 5, the upper outer casing 4 is wrapped on the upper reinforced concrete column body 1, the lower outer casing 5 is wrapped on the lower reinforced concrete column body 1, and the lower end of the upper outer casing 4 and the upper end of the lower outer casing 5 extend out of the reinforced concrete column body 1;
the upper ends of the upper outer-wrapping casing 4 and the core column steel sleeve 7 are fixed on the upper prefabricated reinforced concrete column body 1 through the split screws 18, the lower ends of the lower outer-wrapping casing 5 and the core column steel sleeve 7 are fixed on the lower prefabricated reinforced concrete column body 1 through the split screws 18, and the split screws 18 are multiple.
The number of the replaceable component groups is the same as the number of the sections of the reinforced concrete core column 3, and the replaceable component groups are arranged on the periphery of the reinforced concrete core column 3;
the steel sleeve 6 is arranged in the core area, the middle of the steel sleeve 6 is grooved, the steel sleeve is arranged in the core area of the beam column joint, and two ends of the steel sleeve extend out of the core area for a certain length;
the lower end of an upper outer casing 4 extending out of the reinforced concrete column body 1 is detachably connected with the upper ends of upper replaceable component groups 8 and 9, and the lower ends of an upper outer side replaceable component 8 and an upper inner side replaceable component 9 are detachably connected with the upper end of a steel sleeve 6 in a core area; the lower end of the steel sleeve 6 in the core area is detachably connected with the upper ends of the lower outer side replaceable component 10 and the lower inner side replaceable component 11, and the lower ends of the lower outer side replaceable component 10 and the lower inner side replaceable component 11 are detachably connected with the upper end of the lower outer casing 5.
Prestressing force drawknot muscle 21, prestressing force drawknot muscle 21 are located on the neutral plane of precast reinforced concrete roof beam 2, are provided with in the precast reinforced concrete roof beam 2 and reserve drawknot muscle pore 22, are equipped with drawknot muscle sleeve pipe 23 in the node core space. The axes of the reserved drawknot rib hole 22 and the drawknot rib sleeve 23 are coincided with the axis of the prestressed drawknot rib 21, the drawknot rib sleeve 23 passes through the slot of the steel sleeve 6 in the core area and is connected with the reserved drawknot rib hole 22 in the precast reinforced concrete beam 2, and the inner diameter of the drawknot rib sleeve 23 is larger than the nominal diameter of the prestressed drawknot rib 21. The prestressed tie bars 21 pass through the holes 22 without being bonded and are connected with the sleeves 23 to the prefabricated reinforced concrete beams 2 and the prefabricated reinforced concrete columns and anchored at the corners of the outer frame.
The upper outer casing 4, the lower outer casing 5 and the steel casing 6 in the core area can be hollow steel pipes with square cross sections, can also be hollow steel pipes with circular cross sections or hollow steel pipes with other cross sections. The cross-sectional shapes of the upper outer casing 4, the lower outer casing 5 and the steel sleeve 6 in the core area are preferably consistent with the cross-sectional shape of the reinforced concrete column body 1.
Further, each replaceable component group comprises at least two pairs of replaceable components. The number of pairs of replaceable parts can be selected practically according to the shapes of the upper outer casing 4, the lower outer casing 5 and the steel casing 6 in the core area. When the cross-sectional shapes of the upper outer casing 4, the lower outer casing 5 and the steel casing 6 in the core area are square, each replaceable component group comprises four pairs of replaceable components. When the cross-sectional shapes of the upper outer casing 4, the lower outer casing 5 and the steel casing 6 in the core region are circular, each replaceable component group may include two pairs of replaceable components, or three or more pairs of replaceable components. When the cross-sectional shapes of the upper outer casing 4, the lower outer casing 5 and the steel casing 6 in the core area are other shapes, the number of pairs of replaceable parts included in each replaceable part group can be selected according to actual needs.
Each pair of exchangeable parts comprises an upper outer exchangeable part 8, a lower outer exchangeable part 10 and an upper inner exchangeable part 9, a lower inner exchangeable part 11. The upper outer exchangeable part 8, the lower outer exchangeable part 10, the upper inner exchangeable part 9, and the lower inner exchangeable part 11 are all shields. The guard plate is made of steel plates. The steel plate may be made of one of Q235 steel, Q345 steel, Q390 steel, Q420 steel, or LY100 steel, LY160 steel, LY225 steel. The upper outer-coating sleeve 4, the lower outer-coating sleeve 5, the core area steel sleeve 6 and the core column steel sleeve 7 are made of one of Q235 steel, Q345 steel, Q390 steel and Q420 steel, and the yield strength of the materials selected for the upper outer-coating sleeve 4, the lower outer-coating sleeve 5 and the core area steel sleeve 6 is not lower than that of the materials selected for the guard plate.
In this embodiment, the guard plate may be a planar guard plate, an arc guard plate, or the like. The shape of the guard plate can be selected according to the shapes of the upper outer casing 4, the lower outer casing 5 and the steel casing 6 in the core area. When the cross-sectional shapes of the upper cladding sleeve 4, the lower cladding sleeve 5, and the steel sleeve 6 in the core region are square, the protector plates serving as the upper outside exchangeable part 8, the lower outside exchangeable part 10, the upper inside exchangeable part 9, and the lower inside exchangeable part 11 may be flat protector plates. When the cross-sectional shapes of the upper cladding sleeve 4, the lower cladding sleeve 5, and the steel sleeve 6 in the core region are circular, the protector plates serving as the upper outside exchangeable part 8, the lower outside exchangeable part 10, the upper inside exchangeable part 9, and the lower inside exchangeable part 11 may be arc-shaped protector plates. When the cross-sectional shapes of the upper cladding sleeve 4, the lower cladding sleeve 5, and the steel sleeve 6 in the core region are other shapes, the shapes of the guard plates used as the upper outer exchangeable part 8, the lower outer exchangeable part 10, the upper inner exchangeable part 9, and the lower inner exchangeable part 11 may be selected according to actual needs.
The lower end of an upper outer casing 4 extending out of the prefabricated reinforced concrete column body 1 and the upper end of a steel casing 6 extending out of the core area of the node are arranged between an upper outer replaceable part 8 and an upper inner replaceable part 9 and are detachably connected through a high-strength bolt 19; the upper end of a lower outer casing pipe 5 extending out of the reinforced concrete column body 1 and the lower end of a steel casing pipe 6 extending out of the core area of the node are arranged between a lower outer side replaceable part 10 and an inner side replaceable part 11 and are detachably connected through a high-strength bolt 19; the high-strength bolts 19 are plural.
The existence of the upper outer replaceable part 8, the lower outer replaceable part 10, the upper inner replaceable part 9 and the lower inner replaceable part 11 simultaneously is beneficial to avoiding local bending of the replaceable parts caused by the bending moment borne by the connection parts due to single-side force transmission of the replaceable parts.
The prefabricated reinforced concrete column body 1 further comprises a first longitudinal steel bar 12 and a first stirrup 13 bound on the first longitudinal steel bar 12; the precast reinforced concrete beam 2 also includes third longitudinal reinforcing bars 16 and third stirrups 17 tied to the third longitudinal reinforcing bars 16.
The vertical longitudinal reinforcement comprises a second longitudinal reinforcement 14 arranged in the reinforced concrete core column 3 and a first longitudinal reinforcement 12 arranged in the reinforced concrete column body 1. And second stirrups 15 are bound on second longitudinal steel bars 14 arranged in the reinforced concrete core column 3. A first stirrup 13 is also bound on a first longitudinal steel bar 12 arranged in the reinforced concrete column body 1. The two ends of the second longitudinal steel bar 14 in the reinforced concrete core column 3 extend into and are anchored in the reinforced concrete column body 1.
The longitudinal steel bars and stirrups adopt one steel bar of HPB300, HRB335, HRB400, RRB400 or HRB 500.
The sectional dimensions of the upper outer replaceable part 8, the lower outer replaceable part 10, the upper inner replaceable part 9 and the lower inner replaceable part 11, the height and the thickness of a steel plate, the number of high-strength bolts 19 arranged at the joint and the sectional properties of the upper outer casing 4, the lower outer casing 5 and the steel casing 6 in the core area are determined according to the actual stress condition.
Third longitudinal reinforcement 16 in with reinforced concrete roof beam 2 on the core area steel casing 6, the one-to-one is equipped with the hole, and third longitudinal reinforcement 16 extends behind the hole and fixes on core area steel casing 6 in the prefabricated reinforced concrete roof beam 2.
And the third longitudinal steel bars 16 in the reinforced concrete beam 2 are matched with straight threaded sleeves 20, the end parts of the third longitudinal steel bars 16 in the prefabricated reinforced concrete beam 2 extend through the holes and then are connected with the straight threaded sleeves 20 to be fixed on the inner side of the steel sleeve 6 in the core area, and the number of the straight threaded sleeves 20 is the same as that of the third longitudinal steel bars 16 in the reinforced concrete beam 2.
And after each assembling process is finished, concrete is poured between the core area steel sleeve 6 and the core column steel sleeve 7 at the node to form a whole.
The rigidity and the bearing capacity of the whole section formed by combining the upper outer replaceable part 8, the lower outer replaceable part 10, the upper inner replaceable part 9 and the lower inner replaceable part 11 which are connected by the reinforced concrete core column 3 and the high-strength bolt 19 at the end part of the column are consistent with those of the original reinforced concrete column part, so that the requirements of normal use and the limit state of the bearing capacity of the structure are met.
The invention improves the mechanical property and repairability of the reinforced concrete column end of the main hinge part through the separated reinforced concrete core column 3 and the replaceable component group.
The reinforced concrete core column 3, the upper outer side replaceable part 8, the upper inner side replaceable part 9, the lower outer side replaceable part 10 and the lower inner side replaceable part 11 are arranged at the upper column end and the lower column end of a node, under the combined action of vertical load and horizontal load, the reinforced concrete core column 3 bears main axial pressure and partial bending moment, and the upper outer side replaceable part 8, the upper inner side replaceable part 9, the lower outer side replaceable part 10 and the lower inner side replaceable part 11 bear main bending moment and partial axial force. Under the action of a horizontal load lower than a design value (such as during normal use), the reinforced concrete column is in an elastic stress state; under the action of a horizontal load equivalent to a design value, certain plastic deformation can occur to an upper outer side replaceable part 8, an upper inner side replaceable part 9, a lower outer side replaceable part 10 and a lower inner side replaceable part 11 of the reinforced concrete column, and the reinforced concrete column 3 still keeps an elastic stress state; under the action of horizontal load greatly exceeding the design value, serious plastic deformation can occur to the replaceable parts of the reinforced concrete column, structural damage is mainly concentrated on the replaceable parts with high energy consumption performance, the reinforced concrete core column 3 can be damaged only in a small amount, and the integral failure of the column is effectively avoided. Under the action of strong wind or strong shock, when the replaceable part is damaged, the replaceable part can be replaced by loosening the high-strength bolts 19 at the upper end and the lower end of the replaceable part. The replaceable component has simple structure and low cost of materials, and meets the economic applicability of replaceable structure.
The protective plate is made of the steel plate, so that the mechanical property is better, the energy consumption capability of the plastic hinge at the failure part can be obviously improved, the rigidity degradation rate of the plastic hinge is delayed, the plastic deformation is concentrated on the replaceable part, and the damaged part can be quickly repaired or replaced conveniently.
The problem of rigidity mutation at the connecting part is solved by the constraint effect of the outer casing pipe 4 and the core column steel casing pipe 7, and the reinforced concrete core column 3 is ensured not to be damaged due to the reinforcement of the core column steel casing pipe 7, so that the influence of the replaceable component on the structural performance is within a controllable range. Meanwhile, the core region steel sleeve 6 and the core column steel sleeve 7 restrain the concrete in the node core region, so that the shearing resistance of the node region can be effectively improved.
The invention has stronger applicability, can be conveniently applied to nodes, edge nodes, corner nodes and top-level nodes in a frame structure, has higher assembly degree and less cast-in-place workload.
The advantages and positive effects of the invention are illustrated by theoretical analysis in combination with numerical simulations.
A typical common reinforced concrete column section model is built by adopting section analysis software XTRACT, and then a novel column section model provided by the invention is built by the principle that the axial compression strength is equal, as shown in figure 11. The cross-sectional analysis was performed on each of the two cross-sectional materials to obtain axial force-bending moment curves (N-M curves) of the two cross-sectional materials, and the comparison results are shown in fig. 12. It can be seen that, although the limited compressive bearing capacity of the column is consistent with that of the column when the axis is pressed down, the limited flexural bearing capacity of the column is greatly different from that of the column, and the limited flexural bearing capacity of the section of the novel column is increased by 44% compared with that of the common reinforced concrete column. Moreover, since the tensile strength of concrete is only 1/10 times the compressive strength, the axial tension or eccentric tension bearing capacity of the common reinforced concrete column is low. As can be seen from the N-M curve of the novel column, the novel column still has higher bearing capacity under the condition of tension; and the tensile bearing capacity is improved by 134 percent compared with the common reinforced concrete when the axis is pulled down.
The experiment numerical simulation competition is organized by the anti-collapse professional committee of the earthquake-resistant disaster-prevention division building structure of the Chinese architecture society in 2011-2012 and the Qinghua university, the finite element simulation is carried out on a group of reinforced concrete column experiment models with data disclosure, and the experiment data can be downloaded from related websiteshttp://www.collapse-prevention.net]The column cross-sectional dimensions and the reinforcing bars are shown in FIG. 13, respectively.
A Fiber model of finite element software ABAQUS is adopted and a material subprogram PQ-Fiber provided by professor Pengpo of Qinghua university is called to simulate a test model, the numerical simulation result is well matched with the test result, and the method can be referred to in a reference [ Zhonhao, RC frame strong column and weak beam reliability design improvement and verification considering the random characteristic of the eccentric distance of a column [ D ]. Changshi university.2017 ]. And then, according to the principle that the axial compression strength is equal, the reinforced concrete column in the test is improved into the novel column structural form provided by the invention, a finite element model is established by adopting a multi-scale method, and the analysis result is shown in figure 14. It can be seen that, under the principle that the compressive strength of the axis of the novel column is equal, the horizontal bearing capacity is greatly improved, and the dissipated energy (the area enclosed by the hysteresis curve) is correspondingly increased more.
Due to the constitutive parameters of the material in the actual engineering (peak strength f of concrete)cPeak compressive strain epsilon0Ultimate compressive strain epsiloncuYield strength f of steel bar, steel plate, low yield point steelHRB400、fQ345、fLP160) Has random variability and the statistical parameters are shown in the table 1, thereby causing the resistance of the structure to have large variability. The parameter lambda (lambda is equal to epsilon) is counted by collecting the test data of 88 groups of concrete in domestic and foreign documentscu/ε0) The mean value of lambda of about 1.64 (value of 1.65 in the concrete structure design specification) was obtained. Therefore, the ultimate compressive strain ε in the analysiscuTemporarily taken as the peak compressive strain epsilon01.64 times. In order to study the influence of the variation of the constitutive parameters of the material on the resistance of the common reinforced concrete column and the novel column, a uniform design method is adopted, the peak strength and the peak compressive strain of the concrete and the yield strengths of the steel bar, the steel plate and the low-yield-point steel are taken as random variables, and 37 uniform sample points in the actual space are obtained, as shown in table 2.
TABLE 1 statistical parameters of random variables
Standard value | Mean value of | Standard deviation of | κ | δ | |
fLP160 | 160 | 182.88 | 13.16736 | 1.143 | 0.072 |
fQ345 | 345 | 372.6 | 29.808 | 1.080 | 0.080 |
|
400 | 456 | 31.92 | 1.140 | 0.070 |
fc | 20.1 | 28.341 | 5.38479 | 1.410 | 0.190 |
ε0 | 0.002 | 0.0022 | 0.000308 | 1.100 | 0.140 |
TABLE 2 actual spatial sample points
Sample point | fLP160 | fQ345 | fHRB400 | fc | ε0 |
1 | 143.38 | 312.98 | 402.80 | 20.26 | 0.00184 |
2 | 145.57 | 347.76 | 450.68 | 29.23 | 0.00245 |
3 | 147.77 | 382.53 | 498.56 | 38.21 | 0.00307 |
4 | 149.96 | 417.31 | 546.44 | 13.98 | 0.00178 |
5 | 152.16 | 452.08 | 397.48 | 22.95 | 0.00240 |
6 | 154.35 | 303.04 | 445.36 | 31.93 | 0.00302 |
7 | 156.55 | 337.82 | 493.24 | 40.90 | 0.00173 |
8 | 158.74 | 372.60 | 541.12 | 16.67 | 0.00235 |
9 | 160.93 | 407.37 | 392.16 | 25.64 | 0.00290 |
10 | 163.13 | 442.15 | 440.04 | 34.62 | 0.00168 |
11 | 165.32 | 293.11 | 487.92 | 43.59 | 0.00230 |
12 | 167.52 | 327.88 | 535.80 | 19.36 | 0.00291 |
13 | 169.71 | 362.66 | 386.84 | 28.34 | 0.00163 |
14 | 171.91 | 397.44 | 434.72 | 37.31 | 0.00225 |
15 | 174.10 | 432.21 | 482.60 | 13.08 | 0.00286 |
16 | 176.29 | 283.17 | 530.48 | 22.05 | 0.00158 |
17 | 178.49 | 317.95 | 381.52 | 31.03 | 0.00220 |
18 | 180.68 | 352.72 | 429.40 | 40.00 | 0.00281 |
19 | 182.88 | 387.50 | 477.28 | 15.77 | 0.00153 |
20 | 185.07 | 422.28 | 525.16 | 24.75 | 0.00214 |
21 | 187.26 | 457.05 | 376.20 | 33.72 | 0.00276 |
22 | 189.46 | 308.01 | 424.08 | 42.70 | 0.00148 |
23 | 191.65 | 342.79 | 471.96 | 18.46 | 0.00209 |
24 | 193.85 | 377.56 | 519.84 | 27.44 | 0.00271 |
25 | 196.04 | 412.34 | 370.88 | 36.41 | 0.00143 |
26 | 198.24 | 447.12 | 418.76 | 12.18 | 0.00204 |
27 | 200.43 | 298.08 | 466.64 | 21.16 | 0.00266 |
28 | 202.63 | 332.85 | 514.52 | 30.13 | 0.00137 |
29 | 204.82 | 367.63 | 365.56 | 39.11 | 0.00199 |
30 | 207.02 | 402.40 | 413.44 | 14.87 | 0.00261 |
31 | 209.21 | 437.18 | 461.32 | 23.85 | 0.00132 |
32 | 211.40 | 288.14 | 509.20 | 32.82 | 0.00194 |
33 | 213.60 | 322.92 | 360.24 | 41.80 | 0.00255 |
34 | 215.79 | 357.69 | 408.12 | 17.57 | 0.00127 |
35 | 217.99 | 392.47 | 456.00 | 26.54 | 0.00189 |
36 | 220.18 | 427.24 | 503.88 | 35.52 | 0.00250 |
37 | 222.38 | 462.02 | 551.76 | 44.49 | 0.00312 |
Similarly, the cross-section analysis software XTRACT is adopted to respectively establish the common reinforced concrete column shown in FIG. 11 and the novel column of the invention, and the common reinforced concrete column and the novel column meet the principle that the axial compression strength is equal under the standard material strength. Given the equivalent axial compression ratio of 0.4, the variability of the resistance (bending moment) at the above 37 sample points was analyzed for both sections, and the results are shown in fig. 15. The mean value and the variability of the two are respectively counted, and the result shows that: the average resistance value of the section of the common reinforced concrete column is 222.8kN.m, and the coefficient of variation is 0.202; the mean value of the resistance of the section of the novel column is 304.0kN.m, and the coefficient of variation is 0.108. Therefore, under the same axial compression ratio, the resistance of the section of the novel column under each sample point is larger than that of the section of the common reinforced concrete column, and the variability of the section of the novel column is reduced by about 50 percent compared with that of the section of the common reinforced concrete column.
Further, a single-layer single-span frame model containing novel columns and a conventional reinforced concrete frame model are respectively designed according to the principle that the axial compression strength is equal, the action of the floor slab is considered, and the prestressed tie bars are not arranged. The simulations were performed using the finite element software ABAQUS and invoking the material subroutine PQ-Fiber, and the analysis results are shown in FIGS. 16-17. Due to the reasons of damage accumulation of concrete and the like, the hysteresis curve of the conventional reinforced concrete frame is in an obvious pinching characteristic, while the hysteresis curve of the novel frame is in a fusiform shape, so that the hysteresis loop is fuller. Further analysis shows that the total energy dissipated by the conventional frame and the novel frame is respectively about 261037kN.mm and 579479kN.mm, and the energy consumption capacity of the novel frame is about 2.22 times of that of the conventional frame. The equivalent viscous damping ratio of contrast between them can be seen, after the structure got into the yield stage, because novel frame mainly carries out the power consumption by low yield point steel sheet (removable steel sheet), the power consumption ability is more superior than ordinary reinforcing bar, and equivalent viscous damping ratio increases the range and is bigger, and the structure power consumption ability is corresponding to be improved by a wide margin. FIG. 16 hysteresis curves for a conventional reinforced concrete frame and the novel frame of the present invention; FIG. 17 is a graph showing equivalent viscous damping ratio of a conventional reinforced concrete frame and the novel frame of the present invention.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (6)
1. The utility model provides a prefabricated assembly beam column system of reinforcing structure antidetonation and collapse resistance ability which characterized in that, prefabricated assembly beam column system of reinforcing structure antidetonation and collapse resistance ability includes: at least one prefabricated reinforced concrete column and at least one prefabricated reinforced concrete beam;
the prefabricated reinforced concrete column consists of three sections, wherein two ends of the prefabricated reinforced concrete column are respectively provided with a section of reinforced concrete column body, and the middle part of the prefabricated reinforced concrete column is provided with a section of reinforced concrete core column; the section size of the reinforced concrete core column is smaller than that of the reinforced concrete column body;
the prefabricated reinforced concrete columns on the upper layer and the lower layer of the structure are connected in the middle of the floor height;
the reinforced concrete core column is externally wrapped with a core column steel sleeve, and two ends of the core column steel sleeve extend into the prefabricated reinforced concrete column body; the outer casing comprises an upper outer casing and a lower outer casing, the upper outer casing is wrapped on the upper reinforced concrete column body, the lower outer casing is wrapped on the lower reinforced concrete column body, and the lower end of the upper outer casing and the upper end of the lower outer casing extend out of the reinforced concrete column body;
the upper outer casing sleeve and the upper end of the core column steel sleeve are fixed on the upper prefabricated reinforced concrete column body through a split screw; the lower outer casing sleeve and the lower end of the core column steel sleeve are fixed on the lower prefabricated reinforced concrete column body through a split screw;
the prefabricated assembly beam column system of reinforced structure antidetonation and collapse resistance still includes:
the steel sleeve comprises a core area steel sleeve, wherein the middle of the core area steel sleeve is grooved and arranged in the core area of the beam column node, and two ends of the core area steel sleeve extend out of the core area by a certain length.
2. A prefabricated beam column system for enhancing earthquake resistance and collapse resistance of a structure according to claim 1, wherein the lower end of an upper outer casing pipe extending out of the body of the reinforced concrete column is detachably connected with the upper end of an upper replaceable component group, and the lower end of the upper replaceable component group is detachably connected with the upper end of a steel casing pipe in a core area; the lower extreme of nuclear core district steel bushing and the upper end of lower part removable parts group can be dismantled and be connected, and the lower extreme of lower part removable parts group can be dismantled with the upper end of outsourcing sleeve pipe and be connected down.
3. The precast assembled beam column system for enhanced structural earthquake and collapse resistance of claim 1, further comprising: the prestressed tie bar is arranged on the neutral surface of the prefabricated reinforced concrete beam, a reserved tie bar hole channel is formed in the prefabricated reinforced concrete beam, and a tie bar sleeve is arranged in a node core area; the axis of the reserved drawknot rib hole and the axis of the drawknot rib sleeve are superposed with the axis of the prestressed drawknot rib, the drawknot rib sleeve passes through the slot of the steel sleeve in the core area and is connected with the reserved drawknot rib hole in the precast reinforced concrete beam, and the inner diameter of the drawknot rib sleeve is larger than the nominal diameter of the prestressed drawknot rib; the prestressed tension bonding ribs penetrate through the pore passages without bonding and are connected with the prefabricated reinforced concrete beams and the prefabricated reinforced concrete columns through the sleeves, and the prestressed tension bonding ribs are anchored at the corners of the outer frame.
4. The prefabricated beam column system for enhancing the earthquake resistance and collapse resistance of the structure as claimed in claim 1, wherein the lower end of the upper outer casing pipe extending out of the prefabricated reinforced concrete column body of the upper portion and the upper end of the steel casing pipe extending out of the core region of the node are both arranged between the inner replaceable component and the outer replaceable component of the upper portion and detachably connected through a high-strength bolt; the upper end of the lower outer casing pipe extending out of the lower reinforced concrete column body and the lower end of the core area steel sleeve extending out of the core area of the node are arranged between the lower-part inner side replaceable component and the outer side replaceable component, and the connection can be disassembled through the high-strength bolt.
5. The precast beam column system for enhancing earthquake resistance and collapse resistance of a structure according to claim 1, wherein longitudinal beam ribs are arranged in the precast reinforced concrete beam, holes are formed in the steel sleeve of the core area corresponding to the longitudinal beam ribs in the precast beam, and the longitudinal beam ribs extend through the holes and then are fixed on the steel sleeve of the core area.
6. A reinforced concrete frame of a prefabricated assembled beam-column system applying the reinforced structure with the earthquake resistance and the collapse resistance as claimed in any one of claims 1 to 5.
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