Permanent and temporary combined prefabricated diaphragm wall type subway entrance and exit structure and construction method

Abstract

The invention discloses a permanent and temporary combined prefabricated diaphragm wall type metro entrance and exit structure and a construction method, the structure comprises a structure side wall integrating an enclosure structure and a main body structure, and the structure side wall is an assembled prefabricated diaphragm wall; a first temporary steel support for temporary supporting and a second permanent-temporary combination support for permanent-temporary combination are arranged between the prefabricated underground diaphragm walls, a cast-in-place bottom plate is arranged between the prefabricated underground diaphragm walls, and the second permanent-temporary combination support is located at the elevation position of the top plate. The construction method comprises the following steps that the prefabricated diaphragm wall is assembled and constructed; the foundation pit is excavated to the position below the first temporary steel support; mounting a first temporary steel support; the foundation pit is excavated to the position below the second permanent and temporary combined support; a second permanent and temporary combined support is installed; excavating to the pit bottom, constructing a cushion layer, and constructing a cast-in-place bottom plate; constructing a structural top plate; covering earth on the top plate is backfilled, and the upper segment prefabricated diaphragm wall is removed; and backfilling the residual covering soil and recovering the pavement. The construction period is effectively shortened, and the construction precision is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of underground structure engineering, and in particular relates to a permanent and temporary combined prefabricated ground-connected wall type subway entrance and exit structure and a construction method. Background Art

[0002] At present, the structural construction of subway station entrances and exits still uses the traditional wet method, that is, pouring reinforced concrete on site. Not only is the construction period long, the cost high, and the quality assurance low, but it also causes great pollution to the surrounding areas. Based on the outstanding problems of the existing underground structure scheme, building a new prefabricated underground structure design system is a practical need for rail transit engineering construction and high-quality development.

[0003] Therefore, it is necessary to find a more low-carbon, low-cost prefabricated subway entrance and exit structure and construction method to effectively save concrete, steel and other construction materials, and effectively solve the existing construction environment problems of high labor, poor environment, long construction period, etc. With the maturity of technology and equipment, the market prospects will be broader. Summary of the invention

[0004] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a permanent and temporary combined prefabricated ground-connected wall type subway entrance and exit structure and a construction method.

[0005] The technical solution of the present invention is: a permanent and temporary combined prefabricated ground-connected wall type subway entrance and exit structure, including a structural side wall that integrates a retaining structure and a main structure, the structural side wall is an assembled prefabricated ground-connected wall, a first temporary steel support for temporary support and a second permanent and temporary combined support for permanent and temporary combination are arranged between the prefabricated ground-connected walls, a cast-in-place cast-in-place bottom plate is also arranged between the prefabricated ground-connected walls, and the second permanent and temporary combined support is located at the top plate elevation.

[0006] Furthermore, the second permanent and temporary combined support is also a prefabricated roof beam, and the prefabricated roof beam is a part of the structural roof.

[0007] Furthermore, the structural roof comprises prefabricated roof beams and prefabricated roof composite plates, and the prefabricated roof composite plates are connected between adjacent prefabricated roof beams.

[0008] Furthermore, the prefabricated roof slab cross beams and prefabricated roof slab composite plates are used as casting templates, and cast-in-place composite cast-in-place plates are arranged on the prefabricated roof slab cross beams and prefabricated roof slab composite plates.

[0009] Furthermore, the second permanent-temporary combined support is connected to the prefabricated ground-connected wall through super-high concrete.

[0010] Furthermore, the top plate composite plate and the composite cast-in-place plate are arranged in a step-like manner in the climbing section of the subway entrance and exit.

[0011] Furthermore, a steel mesh is provided in the composite cast-in-place slab, and the steel mesh is connected to the embedded sleeve at the side wall of the prefabricated ground connection wall.

[0012] Furthermore, main structural reinforcements protrude from both ends of the second permanent-temporary combined support, and the main structural reinforcements are connected to embedded sleeves at the side walls of the prefabricated ground connection wall.

[0013] A construction method for a permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure, comprising the following steps: A. Carry out the assembly construction of prefabricated ground-connected walls; B. Excavate the foundation pit to below the first temporary steel support; C. Install the first temporary steel support; D. Excavate the foundation pit to the bottom of the second permanent and temporary combined support; E. Install the second permanent and temporary support; F. Excavate to the bottom of the pit and apply the cushion layer, and construct the cast-in-place bottom plate; G. Construction structure top plate; H. Backfill the top plate with soil and remove the prefabricated ground-connected wall in the upper section; I. Backfill the remaining topsoil and restore the road surface.

[0014] The beneficial effects of the present invention are as follows: The second permanent combined support in the present invention is produced in the factory, with a single production environment, the same performance and controllable quality. After production, it is directly transported from the factory to the construction site for installation, which effectively reduces the construction period and material waste, and also improves the construction accuracy.

[0015] The present invention can not only shorten the construction period and reduce the amount of labor, but also generate almost no construction waste, reduce the area occupied by the construction site, and reduce the impact on the production and life of surrounding residents.

[0016] The prefabricated top plate cross beam and the prefabricated ground connecting wall joints of the present invention adopt ultra-high performance concrete cast-in-place joints, which have excellent physical properties, reduce construction workload, and lower construction difficulty.

[0017] The prefabricated ground-connected wall of the present invention adopts a water-stopping bag + UHPC concrete wet joint connection scheme, which plays a waterproof and guiding role while effectively reducing the amount of steel used. The proportion of assembled prefabricated structures in station entrance and exit structures is relatively high.

[0018] The present invention can effectively reduce carbon emissions and effectively solve many problems in existing construction conditions. As technology and equipment mature, the market prospects will be broader. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1is a cross-sectional view of the entrance and exit of a subway station of the present invention; Figure 2 is a plan view of the entrance and exit of a subway station of the present invention; Figure 3 is a longitudinal section view of the entrance and exit of a subway station of the present invention; Figure 4 It is a schematic diagram of the connection between the prefabricated top plate cross beam and the prefabricated ground connecting wall of the present invention; Figure 5 It is a schematic diagram of the connection between the cast-in-place base plate and the prefabricated ground-connected wall of the present invention; Figure 6 It is a schematic diagram of the connection between the prefabricated ground-connected wall of the present invention; Figure 7 It is a schematic diagram of the prefabricated ground-connected wall of the present invention; Figure 8 It is a schematic diagram of the first temporary steel support erected in the present invention; Fig. 9 It is a schematic diagram of the second permanent combined support of the present invention; Fig.10 It is a schematic diagram of the cast-in-place base plate of the present invention; Fig.11 It is a schematic diagram of the composite cast-in-place slab of the present invention; in: 1 Prefabricated ground wall 2 Cast-in-place base plate 3 The first temporary steel support 4 The second permanent and temporary support 5 Corbel 6 Super high concrete 7 Bored piles 8 Jet grouting piles 9 Water-stop curtain 10 Main structure maintenance pile 11 Main structure side wall 12 Entrance and exit cast-in-place side wall 13 Prefabricated composite slab 14 Composite cast-in-place slab 15 Water stop steel plate 16 Grouting pipe 17 Water-swellable rubber strip 18 Strip capsule seal 19 First embedded angle steel 20 Second embedded angle steel 21 The third embedded angle steel 22 Square steel pipe 23 Self-compacting concrete. DETAILED DESCRIPTION

[0020] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and embodiments: like Figures 1 to 11As shown, a permanent and temporary combined prefabricated ground-connected wall type subway entrance and exit structure includes a structural side wall that integrates a retaining structure and a main structure. The structural side wall is an assembled prefabricated ground-connected wall 1. A first temporary steel support 3 for temporary support and a second permanent and temporary combined support 4 for permanent and temporary combination are arranged between the prefabricated ground-connected walls 1. A cast-in-place cast-in-place bottom plate 2 is also arranged between the prefabricated ground-connected walls 1. The second permanent and temporary combined support 4 is located at the top plate elevation.

[0021] The second permanent combined support 4 is also a prefabricated top plate cross beam, and the prefabricated top plate cross beam is a part of the structural top plate.

[0022] The structural roof comprises prefabricated roof beams and prefabricated roof composite plates 13, and the prefabricated roof composite plates 13 are connected between adjacent prefabricated roof beams.

[0023] The prefabricated roof slab cross beams and the prefabricated roof slab composite plates 13 are used as casting templates, and cast-in-place composite cast-in-place plates 14 are arranged on the prefabricated roof slab cross beams and the prefabricated roof slab composite plates 13.

[0024] The second permanent and temporary combined support 4 is connected to the prefabricated ground connecting wall 1 through super-high concrete 6.

[0025] The top plate composite plate 13 and the composite cast-in-place plate 14 are arranged in a step-like manner at the climbing section of the subway entrance and exit.

[0026] A steel mesh is provided in the composite cast-in-place slab 14 , and the steel mesh is connected to the embedded sleeve at the side wall of the prefabricated ground connecting wall 1 .

[0027] The two ends of the second permanent combined support 4 extend out structural main reinforcements, and the structural main reinforcements are connected to the embedded sleeves at the side walls of the prefabricated ground connection wall 1 .

[0028] Specifically, Figure 1 As shown, both ends of the second permanent combined support 4 are connected to the prefabricated ground connecting wall 1 through super-high concrete 6, and the second permanent combined support 4 is located below the first temporary steel support 3. A corbel 5 is provided at the side wall of the prefabricated ground connecting wall 1, and the corbel 5 can support the second permanent combined support 4.

[0029] Specifically, Figure 2 As shown, the prefabricated ground-connected wall 1 is assembled in sections as the main body of the side wall structure, and bored piles 7 are arranged outside the prefabricated ground-connected wall 1 at the entrance and exit and the cast-in-place side wall 12 at the entrance and exit, and jet grouting piles 8 and main structure maintenance piles 10 are arranged outside the bored piles 7. A water-stop curtain 9 is arranged between the jet grouting piles 8 and the main structure maintenance piles 10, and a main structure side wall 11 is arranged outside the main structure maintenance piles 10.

[0030] Specifically, Figure 3As shown, the structural top plate includes a straight section and a climbing section. In the climbing section, the prefabricated composite slabs 13 and the composite cast-in-place slabs 14 are arranged in steps.

[0031] Specifically, Figure 4 As shown, the prefabricated ground-connected wall 1 is provided with an embedded sleeve at the top plate elevation, and structural main reinforcements protrude from both sides of the second permanent combined support 4. The structural main reinforcements are connected to the embedded sleeves, and super-high concrete 6 is poured between the second permanent combined support 4, the prefabricated ground-connected wall 1, and the corbel 5 for connection.

[0032] More specifically, the steel mesh in the composite cast-in-place slab 14 is also connected to the embedded sleeve, and then the composite cast-in-place slab 14 is cast.

[0033] More specifically, the second permanent bonding support 4 forms concave grooves on both sides, thereby ensuring the firmness of the connection of the super-high concrete 6.

[0034] Specifically, Figure 5 As shown, the prefabricated ground-connected wall 1 is provided with an embedded sleeve at the bottom plate elevation, and the steel bars in the cast-in-place bottom plate 2 are connected to the embedded sleeve.

[0035] More specifically, the prefabricated ground connecting wall 1 forms a groove at the bottom plate elevation, and a water-stop steel plate 15 is arranged in the groove.

[0036] More specifically, the prefabricated ground connecting wall 1 is provided with water-swellable rubber strips 17 at the side wall at the bottom plate elevation, and the water-swellable rubber strips 17 are two in number.

[0037] More specifically, a grouting pipe 16 for grouting is provided between the water-swellable rubber strips 17 .

[0038] Specifically, Figure 6 As shown, a sealing gasket groove is arranged between adjacent prefabricated ground connecting walls 1, and a strip-bag sealing gasket 18 is arranged in the sealing gasket groove, and the strip-bag sealing gasket 18 is in two rows.

[0039] Specifically, two square steel pipes 22 are built into the prefabricated ground connection wall 1 on one side. The square steel pipe 22 serves as an internal fixed foundation. A first embedded angle steel 19 is arranged at the square steel pipe 22. The first embedded angle steel 19 is L-shaped. The free ends of the first embedded angle steel 19 face each other, and the side walls of the first embedded angle steel 19 are flush with the side walls of the prefabricated ground connection wall 1. The side walls of the prefabricated ground connection wall 1 form a strip-shaped groove. The two first embedded angle steels 19 and the strip-shaped groove are enclosed to form an inter-width slot.

[0040] More specifically, two second embedded angle steels 20 are built into the prefabricated ground connecting wall 1 on the other side. The second embedded angle steels 20 are L-shaped, and the free ends of the second embedded angle steels 20 face each other. The second embedded angle steels 20 protrude out of the side wall of the prefabricated ground connecting wall 1 .

[0041] More specifically, the second embedded angle steel 20 can form an interlocking engagement with the first embedded angle steel 19 , thereby achieving connection between adjacent prefabricated ground connection walls 1 .

[0042] More specifically, a compacting groove is formed in the strip-shaped sink groove of the prefabricated ground connecting wall 1 on one side, and a compacting groove is formed at the side wall of the prefabricated ground connecting wall 1 on the other side. The above-mentioned compacting grooves correspond to each other, and self-compacting concrete 23 is poured in the compacting grooves.

[0043] Specifically, the prefabricated ground connecting wall 1 is provided with a third embedded angle steel 21 at the inner side wall of the foundation pit, and the third embedded angle steels 21 of adjacent prefabricated ground connecting walls 1 are welded and fixed.

[0044] Specifically, the prefabricated top slab cross beam serves as the second permanent and temporary combined support 4 during the excavation and construction phase of the station entrance and exit foundation pit, and serves as a partial load-bearing structure of the main structure top slab during the use phase. The prefabricated top slab cross beam is connected to the prefabricated ground connection wall 1 by using UHPC concrete cast-in-place joints.

[0045] Specifically, the prefabricated ground-connected wall and the main structure side wall are integrated into one, saving labor time and cost. The combination of permanent and temporary supports simplifies construction steps, reduces material waste, and reduces construction costs.

[0046] Specifically, the joint between the prefabricated top plate beam and the prefabricated ground connecting wall 1 adopts UHPC (ultra-high performance concrete) cast-in-place joint, which has excellent physical properties, reduces construction workload and reduces construction difficulty.

[0047] Specifically, a water stop bag + UHPC concrete wet joint connection solution is used between each section of the prefabricated ground-connected wall, which plays a waterproof and guiding role while effectively reducing the amount of steel used.

[0048] A construction method for a permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure, comprising the following steps: A. Carry out assembly construction of prefabricated ground-connected wall 1; B. Excavate the foundation pit to below the first temporary steel support 3; C. Install the first temporary steel support 3; D. Excavate the foundation pit to below the second permanent combined support 4; E. Install the second permanent combined support 4; F. Excavate to the bottom of the pit to apply cushion layer and construct cast-in-place bottom plate 2; G. Construction structure top plate; H. Backfill the top plate with soil and remove the upper segment prefabricated ground connection wall 1; I. Backfill the remaining topsoil and restore the road surface.

[0049] Specifically, step A is to assemble the prefabricated ground-connected wall 1, and the specific process is as follows: The mud wall is used to form a trench, with the Z-shaped width of the civil air defense section as the first opening, and assembled on both sides of the entrance and exit to complete the assembly construction of the prefabricated ground-connected wall 1.

[0050] Specifically, step E installs the second permanent combined support 4, and the specific process is as follows: First, the second permanent and temporary combined support 4 uses precast concrete beams, which will later serve as the top plate of the station entrance and exit structure; Then, the second permanent combined support 4 is placed on the side wall of the prefabricated ground connecting wall 1, and the steel bars are connected through the prefabricated embedded sleeves embedded on the prefabricated ground connecting wall 1; Finally, UHPC concrete is used to fill the gap between the precast diaphragm wall 1 and the second permanent combined support 4, and the lateral spacing of the supports matches the width of the precast diaphragm wall 1.

[0051] Specifically, step F excavates the pit to the bottom, applies a cushion layer, and constructs a cast-in-place base plate 2. The specific process is as follows: A cushion layer is applied to the bottom of the pit, and a base plate 2 is cast in situ, and the steel bars are connected through the embedded sleeves embedded in the prefabricated ground connecting wall 1.

[0052] Specifically, step G constructs the structural top plate, and the specific process is as follows: First, assemble the top plate composite plate 13; Then, the composite cast-in-place slab 14 is constructed on the top composite slab 13; Finally, the roof is waterproofed.

[0053] Specifically, in step H, the top plate is backfilled with soil, and the upper segment prefabricated ground connection wall 1 is removed. The specific process is as follows: Backfill the top plate with soil, remove the upper segment prefabricated ground connection wall 1, and process the waterproof closing between the vertical joints above the middle segment prefabricated wall.

[0054] The second permanent combined support in the present invention is produced in the factory, with a single production environment, the same performance and controllable quality. After production, it is directly transported from the factory to the construction site for installation, which effectively reduces the construction period and material waste, and also improves the construction accuracy.

[0055] The present invention can not only shorten the construction period and reduce the amount of labor, but also generate almost no construction waste, reduce the area occupied by the construction site, and reduce the impact on the production and life of surrounding residents.

[0056] The prefabricated top plate cross beam and the prefabricated ground connecting wall joints of the present invention adopt ultra-high performance concrete cast-in-place joints, which have excellent physical properties, reduce construction workload, and lower construction difficulty.

[0057] The prefabricated ground-connected wall of the present invention adopts a water-stopping bag + UHPC concrete wet joint connection scheme, which plays a waterproof and guiding role while effectively reducing the amount of steel used. The proportion of assembled prefabricated structures in station entrance and exit structures is relatively high.

[0058] The present invention can effectively reduce carbon emissions and effectively solve many problems in existing construction conditions. As technology and equipment mature, the market prospects will be broader.

Claims

1. A permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure, including a structural side wall that integrates a retaining structure and a main structure, characterized in that: The structural side walls are assembled prefabricated ground-connected walls (1), a first temporary steel support (3) for temporary support and a second permanent-temporary combined support (4) for permanent-temporary combination are arranged between the prefabricated ground-connected walls (1), and a cast-in-place cast-in-place bottom plate (2) is also arranged between the prefabricated ground-connected walls (1), and the second permanent-temporary combined support (4) is located at the top plate elevation.

2. The permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure according to claim 1 is characterized by: The second permanent combined support (4) is also a prefabricated top plate cross beam, and the prefabricated top plate cross beam is a part of the structural top plate.

3. The permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure according to claim 2 is characterized by: The structural roof comprises prefabricated roof cross beams and prefabricated roof composite plates (13), wherein the prefabricated roof composite plates (13) are connected between adjacent prefabricated roof cross beams.

4. The permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure according to claim 3 is characterized by: The prefabricated roof slab cross beams and the prefabricated roof slab composite plates (13) are used as casting templates, and cast-in-place composite cast-in-place plates (14) are arranged on the prefabricated roof slab cross beams and the prefabricated roof slab composite plates (13).

5. The permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure according to claim 3 is characterized by: The second permanent and temporary combined support (4) is connected to the prefabricated ground-connected wall (1) via super-high concrete (6).

6. The permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure according to claim 4 is characterized by: The top plate composite plate (13) and the composite cast-in-place plate (14) are arranged in a step-like manner at the climbing section of the subway entrance and exit.

7. The permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure according to claim 6 is characterized by: A steel mesh is provided in the composite cast-in-place slab (14), and the steel mesh is connected to a pre-embedded sleeve at a side wall of the prefabricated ground connection wall (1).

8. The permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure according to claim 1 is characterized by: Structural main reinforcements protrude from both ends of the second permanent and temporary combined support (4), and the structural main reinforcements are connected to pre-buried sleeves at the side walls of the prefabricated ground connection wall (1).

9. A construction method for a permanent and temporary prefabricated ground-connected wall type subway entrance and exit structure, characterized in that: The following steps are involved: A. Assembling the prefabricated ground-connected wall (1); B. Excavate the foundation pit to below the first temporary steel support (3); C. Install the first temporary steel support (3); D. Excavate the foundation pit to below the second permanent and temporary support (4); E. Install the second permanent and temporary support (4); F. Excavate to the bottom of the pit, apply the cushion layer, and construct the cast-in-place bottom slab (2); G. Construction structure top plate; H. Backfill the top plate with soil and remove the upper segment prefabricated ground diaphragm wall (1); I. Backfill the remaining topsoil and restore the road surface.

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