Underground long longitudinal structure concrete temperature stress anchoring system for subway
Technical Field
The invention relates to the technical field of constructional engineering, in particular to a temperature stress anchoring system for underground long longitudinal structure concrete of a subway.
Background
Subway engineering is an important municipal traffic engineering in modern cities, urban residents bearing large passenger flows play a major role in traveling, and the engineering quality is hundreds of years.
In underground works such as subways and the like, main waterproof parts of a concrete main structure of the underground works are a bottom plate, a side wall and a top plate, the main waterproof parts consider the requirements of structural stress, economy and clearance of a rail running area, the concrete main structure is basically designed by adopting a one-way plate, the length of the concrete main structure is more than 200 meters, the length of part of the concrete main structure is more than 500 meters, the main structure is poured in sections, and after the concrete main structure is folded in full length, a single-layer plate structure with the length of more than 200 meters is formed, so that the main structure is large in transverse rigidity and small in longitudinal rigidity. Under the action of concrete temperature stress caused by the difference between the casting body temperature and the annual low temperature, the shrinkage value of the concrete can reach dozens of millimeters, the tensile stress of the long and vertical main structure of the subway is increased, the tensile stress value is larger than that of the concrete of the main structure, the main structure is cracked in sections, and horizontal and vertical harmful cracks with transverse penetrability appear.
In water-rich areas, particularly coastal cities such as Shenzhen, underground water has a corrosive effect on concrete and steel bars, the safety and durability of the structure are directly influenced, and the quality of underground engineering such as subways is further influenced by the existence of harmful cracks. Even if the leakage-stopping device can be reluctantly accepted by engineering during delivery and use, in the operation stage, particularly after the water level reaches the designed water level elevation, the leakage of the structure still repeatedly occurs, a construction unit needs to pay a huge amount of leakage-stopping cost, the unit price is more than several times of that in the construction stage, great economic burden is caused to a construction general packet unit, the engineering benefit is reduced, and meanwhile, the social negative influence is caused, so that the safety and the convenience of passengers are threatened.
In an overlength structure similar to subway engineering, the design specification for concrete structures (GB 500100-2010) states that deformation joints or expansion joints should be provided to accommodate the effects of temperature changes. But because subway operation function requires, can not set up movement joint (including expansion joint, subsiding crack) in the station. Therefore, aiming at the problem of temperature stress change of the concrete structure caused by annual temperature difference of the long longitudinal structure, the prior art cannot realize effective constraint action on the shrinkage generated inside the structure, cannot reduce the accumulation of the temperature stress, and cannot achieve the purpose of inhibiting the cracking and water leakage of the long longitudinal structure.
The above disadvantages need to be improved.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a concrete temperature stress anchoring system for a subway underground long longitudinal structure.
The technical scheme of the invention is as follows:
the underground long longitudinal structure concrete temperature stress anchoring system of the subway is characterized in that a plurality of transverse temperature stress post-cast zones and a plurality of groups of anchoring structures are arranged along the longitudinal direction of the underground long longitudinal structure, each anchoring structure comprises an anchoring beam and an anchoring column, and the anchoring beams and the anchoring columns are connected end to form a closed frame.
According to the underground long longitudinal structure concrete temperature stress anchoring system for the subway, the interval between two adjacent post-cast temperature stress zones is within 40-50 meters.
In the subway underground long longitudinal structure concrete temperature stress anchoring system, two adjacent anchoring structures are arranged at two adjacent center pillars, or two adjacent anchoring structure jumping pillars are arranged at two spaced center pillars.
According to the underground long longitudinal structure concrete temperature stress anchoring system for the subway, the anchoring structures are arranged between the center pillars, and the interval between every two adjacent anchoring structures is within 18 meters.
According to the underground long longitudinal structure concrete temperature stress anchoring system for the subway, the interval between two adjacent anchoring structures is less than 18 meters.
According to the underground long longitudinal structure concrete temperature stress anchoring system for the subway, the longitudinal section of the temperature stress post-cast strip is in a convex shape.
Furthermore, water stop steel plates are respectively arranged on two sides of the raised part of the temperature stress post-cast strip and embedded into the inner part of the temperature stress post-cast strip.
In the subway underground long longitudinal structure concrete temperature stress anchoring system, the anchoring columns are connected and anchored with the continuous walls or the piles on two sides through the embedded steel bars or the embedded steel bars.
Furthermore, two side surfaces of the anchoring column are embedded into the reserved recess of the continuous wall, and the steel bars in the anchoring column are implanted into the continuous wall or the pile.
Furthermore, it indulges the muscle with the outside to be provided with the inboard in the diaphragm wall and indulges the muscle, the inboard muscle indent of indulging, the side of anchoring column with set up the filling layer between the muscle is indulged to the inboard, fill with the concrete.
Furthermore, the diameters and the distances between the inner longitudinal bars and the outer longitudinal bars are the same as those between the inner longitudinal bars and the outer longitudinal bars, and reinforcing ribs of the inner longitudinal bars and the outer longitudinal bars are welded with main reinforcing steel bars of the continuous wall.
Further, the continuous wall or the pile and the anchoring column are connected in a reinforcing mode through roughening.
According to the underground long longitudinal structure concrete temperature stress anchoring system for the subway, the anchoring beam in the bottom plate is integrally embedded into the base rock soil for fixation.
The underground long longitudinal structure concrete temperature stress anchoring system for the subway comprises the following construction steps:
s1, arranging transverse temperature stress post-cast strips along the longitudinal direction of an underground long and longitudinal structure, wherein the interval between every two adjacent temperature stress post-cast strips is within 40-50 meters;
and S2, arranging the anchoring structures along the longitudinal direction of the underground long and longitudinal structure, wherein the interval between every two adjacent anchoring structures is within 18 meters.
According to the subway underground long longitudinal structure concrete temperature stress anchoring system, the anchoring beam and the anchoring column are connected end to form the closed frame in a shape like a Chinese character 'kou', and four corners of the closed frame are provided with chamfers.
According to the underground long longitudinal structure concrete temperature stress anchoring system for the subway, the anchoring beam is an exposed beam or a hidden beam.
According to the underground long longitudinal structure concrete temperature stress anchoring system for the subway, the anchoring column is a bright column or a hidden column.
The invention according to the above scheme has the advantages that,
1. the temperature stress post-pouring belt is arranged along the longitudinal direction of the long longitudinal structure, temperature stress caused by temperature drop in the early stage is released, the concrete in the belt is matched with construction in an annual low-temperature time period, the temperature difference between the temperature and the annual low temperature when the concrete structure is folded is reduced, the shrinkage degree caused by the temperature difference is relieved, the temperature stress accumulation after the structure is folded is reduced, and the long longitudinal structure is restrained from cracking.
2. The method comprises the steps of arranging anchoring beams and anchoring columns at intervals along the longitudinal direction of a long longitudinal structure on a top plate, a bottom plate and continuous walls, establishing a high-rigidity anchoring structure, anchoring annual temperature stress on the continuous walls, the top plate and the bottom plate on two sides in a segmented mode through a closed anchoring structure, transmitting the temperature stress generated by annual temperature difference to an underground continuous wall and a rock-soil stratum of a building envelope, blocking the temperature stress from folding, shortening the temperature difference influence length, enabling the tensile stress of concrete to be larger than the temperature stress, and generating effective constraint action inside the structure, so that the purpose of restraining the cracking of the long longitudinal structure is achieved.
The invention uses the convex-shaped temperature stress post-cast strip, increases the contact area between the concrete in the temperature stress post-cast strip and the concrete on two sides, and pours at low temperature time in the year to improve the anti-cracking capability of the temperature stress post-cast strip and reduce the structural temperature when the long longitudinal structure is folded, and the side walls on two sides are provided with the anchoring columns to be anchored with the underground continuous wall or the pile of the enclosure structure, the bottom plate is provided with the anchoring beams to be anchored with the rock-soil layer, and the anchoring beams and the anchoring columns form a closed frame to be encrypted with anti-cracking reinforcing steel bars and improve the rigidity, thereby shortening the length influenced by the temperature difference of the long longitudinal structure, reducing the influence of the temperature stress on the long longitudinal structure, avoiding the structural cracking of the long longitudinal structure caused by the temperature stress, and having simple integral structure without influencing the stress of the main structure.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is a first structural diagram of a temperature stress post-cast strip.
Fig. 2 is a second structural schematic diagram of the temperature stress post-cast strip.
FIG. 3 is a schematic view of an anchoring structure.
Fig. 4 is a schematic view of a connection structure of a base plate and an anchor beam.
Fig. 5 is a first schematic view of a connection structure of the continuous wall and the bottom plate.
Fig. 6 is a schematic view of a connection structure of the continuous wall and the bottom plate.
Wherein, in the figures, the respective reference numerals:
1. post-casting the strip by temperature stress; 2. an anchor beam; 3. an anchor post; 4. a base plate; 5. a continuous wall; 6. inner longitudinal ribs; 7. outer longitudinal ribs; 8. embedding reinforcing steel bars in advance; 9. a water stop steel plate; 10. and (5) filling the layer.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and 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.
It will be understood that when an element is referred to as being "fixed" or "disposed" or "connected" to another element, it can be directly or indirectly located on the other element. The terms "front", "back", "top", "bottom", "inner", "outer", and the like indicate orientations or positions based on the orientations or positions shown in the drawings, and are for convenience of description only and not to be construed as limiting the technical solution. The meaning of "a number" is one or more unless specifically limited otherwise.
Underground long longitudinal structure concrete temperature stress anchoring system of subway sets up a plurality of horizontal temperature stress post-cast strip 1 and a plurality of group anchoring structure along the longitudinal direction of underground long longitudinal structure, and anchoring structure includes anchor beam 2 and anchor post 3, and anchor beam 2 forms closed frame with anchor post 3 end to end.
The construction steps are as follows:
s1, arranging a transverse temperature stress post-cast strip 1 every 40-50 meters along the longitudinal direction of an underground long and longitudinal structure at an annual low temperature time;
s2, arranging anchoring structures at intervals of 9-18 meters along the longitudinal direction of the underground long and vertical structure.
The invention uses the convex-shaped temperature stress post-cast strip 1, increases the contact area between the concrete in the temperature stress post-cast strip 1 and the concrete on two sides, and performs casting in low temperature time every year to improve the anti-cracking capability of the temperature stress post-cast strip 1, reduce the structural temperature when the long and longitudinal structure is folded, and arranges anchoring columns 3 on two sides to be anchored with the underground continuous wall 5 of the enclosure structure, arranges anchoring beams 2 to be anchored with rock-soil layers, and forms a closed frame by the anchoring beams 2 and the anchoring columns 3, and both encrypts anti-cracking reinforcing steel bars to improve the rigidity, thereby shortening the length influenced by the temperature difference of the long and long longitudinal structure, reducing the influence of the temperature stress on the long and longitudinal structure, avoiding structural cracking of the long and longitudinal structure caused by the temperature stress, having simple integral structure and not influencing the main body structure.
In one embodiment, the interval between two adjacent temperature stress post-cast strips 1 is within 40-50 meters. The temperature stress post-cast strip 1 is arranged to prolong the early stress release proportion as much as possible, reduce the total amount of stress accumulation after folding and reduce the stress on a longitudinal structure.
When this temperature stress post-cast strip 1 is under construction, its pouring process is the same with conventional post-cast strip, it needs to be noted that, because of the setting up of anchoring structure leads to the temperature stress accumulation of major structure to reduce, the shrinkage factor reduces, for adapting to this condition, temperature stress post-cast strip 1 needs to satisfy:
1. the indexes such as strength and the like of the concrete are the same as those of the structural concrete on the two sides;
2. adopting 60-day strength evaluation to prepare concrete so as to reduce the using amount of cementing materials and reduce the hydration heat and the shrinkage of the concrete;
3. from the final setting of concrete, the plate adopts running water cooling and water storage to preserve moisture, and the wall adopts gunny bag to apply surface running water cooling and water storage to preserve moisture.
In addition, the construction time of the temperature stress post-cast strip 1 is selected to be set at low temperature in the year as much as possible, so that the temperature difference between the concrete temperature and the lowest temperature in the year when the main body structure is folded is reduced, and the temperature stress of the long longitudinal structure caused by the temperature difference in the year is reduced.
In one embodiment, as shown in fig. 1 and 2, the longitudinal section of the temperature stress post-cast strip 1 on the continuous wall 5 or the bottom plate 4 is convex. The contact area between the concrete in the temperature stress post-cast strip 1 and the concrete on two sides is increased, and if necessary, the construction form needs to be optimized according to the temperature stress characteristic so as to release the temperature stress before folding as much as possible and reduce the accumulation of the temperature stress after folding. When the section of the temperature stress post-cast strip 1 is observed, the temperature stress post-cast strip 1 is uniformly divided by the middle convex part, and the sizes of the depressions at the two ends are consistent with the size of the middle convex part.
In one embodiment, the two sides of the convex part of the temperature stress post-cast strip 1 are respectively provided with a water stop steel plate 9, and the water stop steel plates 9 are embedded in the temperature stress post-cast strip 1.
In one embodiment, two adjacent anchor structures are provided at two adjacent king pillars, or two adjacent anchor structure jumping pillars are provided at two spaced king pillars. In subway engineering, a subway station is basically provided with longitudinal beams, wherein the distance between columns is 9 meters, anchoring structures are continuously arranged on central columns, and the arrangement of column jumping can also be carried out at intervals of one central column, so that the distance between two adjacent anchoring structures is 9 meters or 18 meters.
In subway engineering, there is the subway station for not having center pillar structure, can set up anchor beam 2 or anchor post 3 according to the calculated result this moment, considers that the structure supports and truncates temperature stress influence length, and the interval is within 18 meters between the adjacent anchor structure of twice is good, should not exceed 18 meters to the greatest extent, and the fracture risk is lower like this. In one embodiment, two adjacent anchoring structures are spaced 9-18 meters apart.
In one embodiment, as shown in fig. 3, the anchoring beam 2 and the anchoring column 3 are connected end to form a closed frame in a shape of a Chinese character 'kou', and four corners of the closed frame are provided with chamfers. The structure is matched with the shape and the structure arrangement of an underground engineering-subway station, so that the structure can be matched with other structures to be arranged into different shapes, and only the anchoring beam 2 and the anchoring column 3 are connected end to form a closed anchoring frame in the inner space of the underground engineering.
In one embodiment, as shown in fig. 4, 5 and 6, two side surfaces of the anchor post 3 are embedded into a groove provided in an underground continuous wall 5 of the building envelope, and are connected and anchored with the continuous wall 5 through embedded steel bars 8 or embedded steel bars, and a filling layer 10 is provided between the groove and the anchor post 3, and concrete is filled therein.
An inner longitudinal rib 6 and an outer longitudinal rib 7 are arranged in an underground continuous wall 5 of the enclosure structure, the diameter and the distance between the inner longitudinal rib 6 and the outer longitudinal rib 7 are the same as those of the continuous wall 5, and reinforcing ribs of the inner longitudinal rib 6 and the outer longitudinal rib 7 are welded with main reinforcing steel bars of the continuous wall 5.
The surfaces of the concrete of the continuous wall 5 and the anchoring column 3 are roughened so as to realize adhesion fixation and strengthen connection during pouring.
The anchoring beam 2 arranged in the bottom base plate of the anchoring structure is integrally embedded into the base rock soil to be fixed, the steel bar area and the reinforcement ratio of the anchoring beam 2 are improved, the anchoring capacity of the anchoring beam 2 can be improved, and the structural rigidity of the bottom anchoring beam 2 can be improved so as to intercept temperature stress accumulation.
When the environmental temperature changes, the shrinkage rate of the steel bar is small, and the steel bar is not influenced by the environment or the building structure and shrinks along with the shrinkage, so that the steel bar can be regarded as not generating tensile stress and not influencing the main structure of the concrete to generate cracks. Therefore, on the basis that the original steel bars are arranged in a penetrating mode, the steel bar distribution area and the steel bar distribution rate between the continuous wall 5 and the anchoring column 3 are improved, the steel bars are arranged in an encrypted mode, the integral rigidity and anti-cracking capacity are improved, meanwhile, the anchoring capacity of the anchoring beam 2 and the anchoring column 3 is improved, the temperature stress accumulation is cut off, the length of the affected length of the temperature difference is shortened, the temperature stress on the long longitudinal structure is divided into a plurality of sections, and the cracking risk of the main structure is reduced.
In one embodiment, the anchoring beam 2 is a hidden beam and the anchoring post 3 is a hidden post. The hidden beams are arranged because of the influence of the layer height and the clearance of the rail running area, so that the hidden columns cannot be arranged under the condition of the bright beams, and the arrangement of the hidden columns is the same. The hidden beam and the exposed beam have the same action and mechanism, the steel bar density between the beam and the top plate and between the beam and the bottom plate 4 is improved, the longitudinal rigidity is increased, the stress closure is prevented, and the length influenced by the temperature difference is shortened. However, because the hidden beams or the hidden columns are buried in the concrete, the section size is the same as the thickness of the bottom plate 4 and the continuous wall 5, the structural rigidity is improved a little, the effect is obviously weaker than that of the exposed beams, and the hidden beams or the hidden columns can be compensated by reducing the distance between the anchoring structures.
The post-pouring belt 1 for temperature stress is arranged along the longitudinal direction of the long longitudinal structure, the temperature stress caused by temperature drop in the early stage due to the fact that part of the temperature stress is released in the early stage is released, and construction is matched with the annual low-temperature time period, the temperature difference between the temperature and the annual low temperature when the concrete structure is folded is reduced, the shrinkage degree caused by the temperature difference is reduced, the temperature stress accumulation after the structure is folded is reduced, and the long longitudinal structure is prevented from cracking.
Along the longitudinal direction of the long longitudinal structure, on the top plate, the bottom plate 4 and the continuous wall 5, an anchoring beam 2 and an anchoring column 3 are arranged at certain intervals to establish a high-rigidity anchoring structure, the continuous wall 5 or piles, the top plate and the bottom plate 4 on two sides are anchored by sections through the closed anchoring structure, the temperature stress generated by the annual temperature difference is transmitted to the underground continuous wall 5 of the enclosure structure or the piles and the rock-soil stratum, the temperature stress is blocked from folding, the temperature difference influence length is shortened, the tensile stress of concrete is larger than the temperature stress, an effective constraint effect is generated inside the structure, and the purpose of inhibiting the cracking of the long longitudinal structure is achieved.
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.