CN212506288U

CN212506288U - Cast-in-place reinforced concrete foundation pit inner supporting structure

Info

Publication number: CN212506288U
Application number: CN202020813824.1U
Authority: CN
Inventors: 刘尚; 宋千军; 郑鹏; 车其杰; 吴平
Original assignee: Sixth Construction Co Ltd of China Construction Fourth Engineering Division Co Ltd
Current assignee: Sixth Construction Co Ltd of China Construction Fourth Engineering Division Co Ltd
Priority date: 2020-05-15
Filing date: 2020-05-15
Publication date: 2021-02-09
Anticipated expiration: 2030-05-15

Abstract

An in-situ cast reinforced concrete foundation pit inner supporting structure comprises a plurality of unit steel bar assemblies which are arranged in a series connection mode and are detachably connected; the unit steel bar assemblies comprise steel bar cages and connecting pieces connected to two ends of the steel bar cages, and concrete is poured on each unit steel bar assembly except the joints of the adjacent unit steel bar assemblies. The supporting structure has high rigidity, avoids environmental pollution caused by blasting, wire sawing and mechanical breaking, can process the reinforcement cage and the embedded part connecting plate into a whole in a factory, and simultaneously improves the construction and dismantling efficiency by adopting a segmented construction technology.

Description

Cast-in-place reinforced concrete foundation pit inner supporting structure

Technical Field

The invention relates to the technical field of construction engineering construction, in particular to an inner support structure of a cast-in-place reinforced concrete foundation pit.

Background

Along with the rapid development of economy in China, the scale of urban construction is continuously enlarged, high-rise buildings, super-high-rise buildings and other buildings are built around the existing buildings, the excavation depth of a foundation pit is continuously increased, and therefore the requirement on deep foundation pit excavation technology is higher and higher. At present, a deep foundation pit support adopts a mode of adding a horizontal inner support to a vertical support, the horizontal inner support has more concrete structures and steel structures, the whole construction is completed on site, the site workload is large, the rigidity of the concrete inner support structure is large, the construction period is long, the inner support structure is generally dismantled through blasting, concrete breaking and dismantling and the like during dismantling, the dismantling efficiency is low, and the environmental pollution is large. Therefore, the construction technology for the mechanical connection subsection of the inner support of the cast-in-place reinforced concrete foundation pit is provided, and the inner support of the foundation pit is fast to remove without environmental pollution.

Disclosure of Invention

The invention aims to solve the technical problem of providing a cast-in-place reinforced concrete foundation pit inner support structure, and the segmented support structure can solve the problems of low support dismantling speed, environmental pollution caused by dismantling construction and the like in the existing foundation pit concrete inner support construction technology.

In order to solve the technical problem, the invention adopts the technical scheme that the cast-in-place reinforced concrete foundation pit inner support structure comprises a plurality of unit reinforcing steel bar assemblies which are arranged in a series connection mode and are detachably connected; the unit steel bar assemblies comprise steel bar cages and connecting pieces connected to two ends of the steel bar cages, and concrete is poured on each unit steel bar assembly except the joints of the adjacent unit steel bar assemblies.

The connecting piece comprises a square steel plate, and the reinforcement cage is connected with the square steel plate; through holes for connection are respectively formed in the square steel plates positioned on the two sides of the reinforcement cage; the adjacent square steel plates are connected together through bolts; the bolts are positioned at both sides of the concrete of each unit steel bar assembly.

The fixed steel bar joint that is provided with of reinforcing bar position department that corresponds the steel reinforcement cage on the square steel sheet, steel bar joint links together through threaded sleeve and steel reinforcement cage and forms the unit reinforcing bar subassembly.

And a plurality of anchoring steel bars are fixedly arranged on the square steel plate. And reinforcing ribs are also arranged on the square steel plates.

The cast-in-place reinforced concrete foundation pit inner support structure can be completed by the construction technology comprising the following steps of: 1) dividing construction units for the concrete inner support structure according to the lifting capacity of the field lifting equipment; 2) processing unit steel bar assemblies required by construction units in batches; 3) constructing a cushion layer of the support structure in the foundation pit while performing the step 2); 4) hoisting the unit steel bar assemblies to the cushion layer, and arranging the unit steel bar assemblies in series in sequence and adjacently along the length of the cushion layer; then connecting adjacent unit steel bar assemblies together in a detachable mode to form a steel bar structure of the supporting structure; 5) erecting a template; 6) pouring concrete, wherein the detachable connection position of the unit steel bar assemblies is positioned on the outer side of the poured concrete; 7) and excavating away the cushion layer during foundation pit excavation, removing the detachable joints of the unit reinforcing steel bar assemblies after the foundation pit excavation is finished and the support replacement construction is completed, enabling each unit reinforcing steel bar assembly of the poured concrete to be an independent section structure, and hoisting each section of reinforced concrete unit out of the foundation pit to complete the removal.

According to the cast-in-place reinforced concrete foundation pit inner support structure, a concrete inner support is divided into construction units in advance according to the hoisting capacity of on-site hoisting equipment, and unit steel bar assemblies with connecting plates are manufactured in batches by constructing steel bars of the divided construction units in a factory. When the construction, only need to pass through bolted connection with unit reinforcing bar subassembly and be in the same place, carry out concrete placement again and can accomplish bearing structure's construction. And after the foundation pit is excavated and the support is replaced, the high-strength bolts at the connecting plates can be detached according to on-site deployment, so that the segmented quick removal of the support structure in the foundation pit is realized. The problems that in the existing concrete inner support construction technology, the support dismantling speed is slow, the dismantling construction causes pollution to the environment and the like are fundamentally solved.

Drawings

Fig. 1 is a schematic side view of a support structure.

Fig. 2 is a schematic side view of the supporting structure after the formwork is erected.

Fig. 3 is a schematic sectional structural view of the support structure after concrete is poured.

Detailed Description

In order that the present disclosure may be more readily and clearly understood, reference will now be made to fig. 1-3 for a more detailed description of the present disclosure, taken in conjunction with the accompanying drawings.

Firstly, according to the size of a foundation pit, the hoisting capacity of hoisting equipment, the size, the number, the weight and the like of reinforcing steel bars of an inner supporting structure of the foundation pit, the inner supporting structure is divided into sections, and a supporting beam or a supporting column and the like are divided into a plurality of construction units.

And according to the divided lengths of the construction units, integrally processing the unit steel bar assemblies consisting of the steel bar cages 2 of the construction units and the connecting pieces in batches in a factory. The unit steel bar component of each construction unit comprises a steel bar cage 2 and connecting pieces located at two ends of the steel bar cage. The connecting piece comprises a connecting plate 3 and an anchoring steel bar 4. The connecting plate is a square steel plate, and as the connecting plate needs to have enough bending resistance and can transmit axial pressure, a plurality of reinforcing ribs can be arranged on the connecting plate to improve the bending strength of the connecting plate. Two ends of the reinforcement cage 2 are fixed on the connecting plate. And connecting through holes are formed in the connecting plates positioned on the two sides of the reinforcement cage. The reinforcement cage comprises a steel bar and stirrups, wherein the two ends of the steel bar with required size are respectively fixedly connected to the reinforcement joints on the connecting plate through connecting devices, then the stirrups are bound on the steel bar, and then the stirrups are bound on the periphery of the steel bar to form the reinforcement cage. The unit reinforcement assembly is formed by fixing the reinforcement cage and the connecting piece together.

The anchoring reinforcing steel bars and the reinforcing steel bars of the reinforcing cage are arranged in a staggered mode, and the anchoring reinforcing steel bars are combined with the concrete 5 in an enhanced mode. The steel reinforcement cage can be connected through welding mode with the connecting plate, also can be connected through the mode of dismantling, for example the mode of ligature is connected or is set up the joint on the connecting plate, and the rethread sleeve is connected with the steel reinforcement cage.

And (3) constructing the cushion layer 1 of the inner support structure while processing the unit steel bar assemblies. The cushion layer is generally a concrete structure with certain width and thickness, a rammed earth layer structure, a brick-concrete structure and other easily-dismantled structures. The width of the cushion layer structure is larger than or equal to the width of the inner support structure.

After the cushion layer construction is finished, positioning and paying off are carried out on the cushion layer, the unit steel bar assemblies conveyed to a construction site are hoisted to the cushion layer, and the unit steel bar assemblies are arranged in series, so that the connecting plates at the two ends of each unit steel bar assembly are arranged in an attached mode. After the positions of the unit steel bar assemblies are fixed, the connecting plates of the adjacent unit steel bar assemblies are connected together through the high-strength bolts 6 to form the integral steel bar structure of the supporting structure. The unit steel bar assemblies processed in batches in a factory are hoisted, installed and fixed on the site, so that the step of steel bar binding construction on the site is saved, the unit steel bar assemblies can be processed before or synchronously with cushion layer construction, and the construction time is shortened.

After the unit steel bar assemblies are hoisted and installed, a template 7 is erected, and bolts are located on the outer side of the template; and then concrete 5 is poured, and after the concrete is poured, the bolts at the connecting plates are positioned at two sides of the reinforced concrete beam. And then, carrying out foundation pit excavation, wherein in the process of the foundation pit excavation, the cushion layer is moved away along with the foundation pit excavation, and only the support structure in the foundation pit is remained. And after the foundation pit is excavated and the support replacement construction is completed, dismantling the supporting structure, and during dismantling, firstly unscrewing the bolts at the connecting plates of the unit reinforcing steel bar assemblies, wherein concrete does not exist between the connecting plates, so that after the bolts are unscrewed, the supporting structure becomes a reinforced concrete unit with a separated section. And hoisting the segmented reinforced concrete units out of the foundation pit one by one through hoisting equipment, namely realizing the complete dismantling of the supporting structure. The supporting structure is designed and constructed in a segmented mode, compared with the traditional dismantling of integral reinforcement binding construction, a large amount of dismantling time and dismantling amount are saved, and the environment is protected.

The cast-in-place reinforced concrete foundation pit inner support structure is convenient to construct and high in feasibility, solves the problems that in the existing cast-in-place concrete inner support construction technology, the support dismantling speed is low, the dismantling construction causes pollution to the environment and the like, and has a good popularization and application prospect.

Claims

1. A cast-in-place reinforced concrete foundation pit inner supporting structure is characterized by comprising a plurality of unit reinforced bar assemblies which are arranged in a series connection mode and are detachably connected; the unit steel bar assemblies comprise steel bar cages and connecting pieces connected to two ends of the steel bar cages, and concrete is poured on each unit steel bar assembly except the joints of the adjacent unit steel bar assemblies.

2. A cast-in-place reinforced concrete foundation pit internal support structure as claimed in claim 1, wherein the connectors comprise square steel plates, and the reinforcement cage is connected with the square steel plates; through holes for connection are respectively formed in the square steel plates positioned on the two sides of the reinforcement cage; the adjacent square steel plates are connected together through bolts; the bolts are positioned at both sides of the concrete of each unit steel bar assembly.

3. The support structure in a cast-in-place reinforced concrete foundation pit as claimed in claim 2, wherein a steel bar joint is fixedly arranged on the square steel plate at a position corresponding to a steel bar of the steel bar cage, and the steel bar joint is connected with the steel bar cage through a sleeve with threads to form a unit steel bar assembly.

4. A cast-in-place reinforced concrete foundation pit internal support structure as claimed in claim 3, wherein a plurality of anchoring steel bars are further fixedly arranged on the square steel plate.

5. A cast-in-place reinforced concrete foundation pit internal support structure as claimed in claim 3, wherein reinforcing ribs are further provided on the square steel plates.