Method for removing support without dismantling after station connection post excavation

Abstract

The present application relates to the technical field of subway station construction, in particular to a method for removing supports without dismantling at a rear cutting working condition of a station junction. According to the cutting sequence of the main body diaphragm wall, an L-shaped fixed plate is buckled at the corner of the top surface of the auxiliary structure, and the horizontal section of the fixed plate is fixed to the top surface of the auxiliary structure through expansion bolts, and a steel pipe is welded on the vertical section of the fixed plate, and the steel pipe is filled with C20 fine stone concrete and the outer end is supported on the main structure. Compared with the traditional segmented pouring of the post-pouring band, the method sequentially cuts off the entire post-pouring band area, adds a supporting structure in the post-pouring band area to ensure the stability of the whole, and then pours the whole, and the supporting structure does not need to be dismantled, which shortens the construction period, saves the maintenance period of segmented pouring concrete and the time of dismantling the supports, ensures the integrity of the concrete, and reduces the leakage risk between the segmented pouring structures.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of subway station construction, in particular to a method for removing supports without disassembly at a rear cutting working condition of a station connection. BACKGROUND

[0002] During the implementation of the subway station auxiliary engineering, the position connected with the subway station is usually the reinforced concrete structure of the entrance, the wind pavilion, the transfer channel and the like. In combination with the construction technology and the foundation pit support form, the main enclosure structure at the connection needs to be cut after the construction of the auxiliary structure. The conventional form is to cut the cut section by section and to pour the concrete by section to ensure the stability of the foundation pit. However, this form has a great influence on the construction period. The concrete maintenance period during the segmented implementation after cutting is long. The construction of the post-pouring belt is required to be not less than 42 days according to the specification, which has a great influence on the construction progress. Moreover, there is a risk of permeation of the concrete joint between the segmented construction. SUMMARY

[0003] The present application aims to solve the above problems and provides a method for removing supports without disassembly at a rear cutting working condition of a station connection to speed up the construction progress.

[0004] The present application solves the problem by adopting the technical scheme of:

[0005] A method for removing supports without disassembly at a rear cutting working condition of a station connection, comprising the following steps:

[0006] S1: after the completion of the main structure, the first reinforced concrete support between the auxiliary structure enclosure pile, the crown beam and the main body diaphragm wall is constructed.

[0007] S2: the auxiliary foundation pit is excavated by layers to the bottom of the second and third supports and the steel support is installed in time between the main body diaphragm wall and the main body diaphragm wall and the prestress is applied until the excavation reaches the bottom of the pit. The concrete cushion is poured. With the excavation progress, the main body diaphragm wall is pre-blocked in advance and the lifting hole is drilled on each diaphragm wall in advance.

[0008] S3: the bottom plate and part of the side wall are poured. After the bottom plate reaches the design strength, the third steel support is removed. The side wall is continuously poured. After the side wall reaches the design strength, the second steel support is removed.

[0009] S4: the side wall and the top plate are continuously poured.

[0010] S5: after the concrete strength meets the strength requirement, the main body diaphragm wall is divided into three blocks including the two sides and the middle and is cut from the outside to the inside in turn. The rope saw is used to cut the crown beam, the concrete support and the concrete tie rod at the diaphragm wall. The main continuous wall is cut into blocks and is lifted away.

[0011] S6: according to the cutting sequence of the main body wall, the L-shaped fixed plate is buckled at the top corner of the auxiliary structure, and the horizontal section of the fixed plate is fixed to the top surface of the auxiliary structure by expansion bolts, and a steel pipe is welded on the vertical section of the fixed plate, and the steel pipe is filled with C20 fine stone concrete and the outer end is supported on the main structure.

[0012] S7: after the main body wall is broken and the support is set, the frame template is erected, the steel bar is bound, and the whole concrete pouring construction is carried out.

[0013] The application adopts the above technical scheme, compared with the prior art, has the outstanding characteristics that:

[0014] Compared with the traditional post-pouring band segment pouring, the method sequentially cuts off the whole post-pouring band area, adds a support structure in the post-pouring band area to ensure the stability of the whole, then pours the whole, and the support structure does not need to be removed, thereby shortening the construction period, saving the segment pouring concrete curing period and the time for removing the support, ensuring the integrity of the concrete, and reducing the leakage risk between the segment pouring structures.

[0015] As a preferred embodiment, the further technical scheme of the application is:

[0016] The lifting hole is located at the position of 1 / 3 of the upper part of each ground wall, and the diameter of the lifting hole is φ110mm.

[0017] The fixed plate is made of 20mm steel plate, the diameter of the steel pipe is 50mm, and the expansion bolt is M20. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the support between the auxiliary structure and the main ground wall of the embodiment of the application;

[0019] Figure 2 It is a structural schematic diagram of the main ground wall block structure of the embodiment of the application;

[0020] Figure 3 It is a pouring structure schematic diagram of the auxiliary structure of the embodiment of the application;

[0021] Figure 4 It is a structural schematic diagram of the main ground wall partial cutting structure of the embodiment of the application;

[0022] Figure 5 It is a structural schematic diagram of the support structure installation structure of the embodiment of the application;

[0023] Figure 6 It is a structural schematic diagram of the support structure of the embodiment of the application;

[0024] In the figure, the main ground wall 1, the fixed plate 2, the steel pipe 3, and the auxiliary structure 4 are marked. EMBODIMENT

[0025] The present application is further described below in conjunction with examples, which are intended to better illustrate the present application and are not intended to limit the scope of protection of the present application.

[0026] S1: After the completion of the main structure, the first reinforced concrete support between the construction of the auxiliary structure 4, the fender pile, the crown beam and the main body of the wall 1 is constructed.

[0027] S2: The auxiliary foundation is excavated in layers to the second and third support bottom, and the steel support between the main body of the wall 1 is installed in time, and prestressed, until the excavation to the bottom of the pit, the concrete cushion is poured, and the main body of the wall 1 is pre-blocked in advance according to the excavation progress, and a lifting hole is drilled in advance on each wall, the lifting hole is located at 1 / 3 of the upper part of each wall, and the lifting hole is φ110mm.

[0028] S3: Pour the bottom plate and part of the side wall, after the bottom plate reaches the design strength, remove the third steel support, continue to pour the side wall, and after the side wall reaches the design strength, remove the second steel support.

[0029] S4: Continue to pour the side wall and the top plate.

[0030] S5: After the concrete strength meets the strength requirement, the main body of the wall 1 is divided into three parts, including two sides and the middle, and is cut off in turn from outside to inside, the crown beam, the concrete support and the concrete tie rod at the wall are cut off by using a rope saw, and then the main continuous wall is cut off and lifted away.

[0031] S6: According to the cutting sequence of the main body of the wall 1, an L-shaped fixed plate 2 is prepared to be buckled at the top corner of the auxiliary structure 4, the fixed plate 2 is made of 20mm steel plate, the width is 80mm, the horizontal segment is 200mm long, the vertical segment is 400mm long, and the horizontal segment of the fixed plate 2 is fixed with the top surface of the auxiliary structure 4 by expansion bolts, a steel pipe 3 is welded on the vertical segment of the fixed plate 2, the steel pipe 3 is 50mm in diameter, the expansion bolts are M20, the steel pipe 3 is filled with C20 fine stone concrete and the outer end is supported on the main structure, and the fixed plate 2 and the steel pipe 3 form a support structure to ensure the stability of the post-pouring belt.

[0032] S7: After the completion of the main body of the wall 1 and the completion of the support setting, the frame template is erected, the steel bars are bound, and the whole concrete pouring construction is carried out.

[0033] Compared with the traditional segmented pouring of the post-pouring belt, the present method sequentially cuts off the whole post-pouring belt area, adds a support structure in the post-pouring belt area to ensure the stability of the whole, and then pours the whole, and the support structure does not need to be removed, which shortens the construction period, saves the curing period of the segmented pouring concrete and the time of removing the support, ensures the integrity of the concrete, and reduces the leakage risk between the segmented pouring structures.

[0034] The above description is only the preferred embodiment of the present application, and is not intended to limit the scope of the present application. Any equivalent changes made according to the present application description and its drawings are included in the scope of the present application.

Claims

1. A method for eliminating the need to dismantle supports during post-excavation work at station joints, characterized in that: Includes the following steps: S1: After the main structure is completed, construct the auxiliary structure retaining piles, capping beams, and the first reinforced concrete support between the auxiliary structure and the main diaphragm wall; S2: Excavate the auxiliary foundation pit in layers to the bottom of the second and third supports and install steel supports between them and the main diaphragm wall in a timely manner, and apply prestress until the bottom of the pit is reached. Pour a concrete cushion layer. As the excavation progresses, pre-divide the main diaphragm wall into blocks in advance, and drill lifting holes in advance on each block of diaphragm wall. The lifting holes are located at the upper 1 / 3 of each block of diaphragm wall, and the lifting holes are φ110mm. S3: Pour the base slab and part of the side walls. After the base slab reaches the design strength, remove the third steel support and continue pouring the side walls. After the side walls reach the design strength, remove the second steel support. S4: Continue pouring the side walls and top slab; S5: After the concrete strength meets the requirements, the main diaphragm wall is divided into three parts, including the two sides and the middle, and is cut off from the outside to the inside. The capping beam, concrete support and concrete tie rod of the diaphragm wall are cut in sections using a wire saw. Then the main diaphragm wall is cut off in sections and lifted away. S6: Following the cutting sequence of the main ground ties, prepare an L-shaped fixing plate to be fastened at the corner of the top surface of the auxiliary structure. The horizontal section of the fixing plate is fixed to the top surface of the auxiliary structure by expansion bolts. A steel pipe is welded on the vertical section of the fixing plate. C20 fine stone concrete is poured into the steel pipe and the outer end is supported on the main structure. S7: After the main ground wall is demolished and the support is set up, the formwork is erected, the steel bars are tied, and the overall concrete is poured.

2. The method for eliminating the need to dismantle supports during post-excavation work at station connection points according to claim 1, characterized in that: The fixing plate is made of 20mm steel plate, the steel pipe is 50mm in diameter, and the expansion bolts are M20.

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