A subway station box type retaining wall structure and a construction method thereof

Abstract

The present application belongs to the technical field of subway station building construction, and discloses a subway station box type retaining wall structure and a construction method. In view of the problems in the prior art, the rigid connection structure of the station crown beam and the station enclosure structure is adopted to increase the overall rigidity, then the retaining wall bottom plate is rigidly connected with the station crown beam, the retaining wall waist beam and the support beam force transmission component are arranged to strengthen the bottom constraint of the retaining wall structure. The retaining wall structure can meet the stress requirements of the pedestrian walkway or the vehicle roadway, and has good overall stability. The whole construction method is reasonable in design, simple and feasible in construction method, safe and reliable, and convenient for construction.

Description

Technical Field

[0001] This invention belongs to the field of subway station building construction technology, specifically relating to a box-type retaining wall structure and construction method for subway stations. Background Technology

[0002] With the rapid development of my country's rail transit engineering, subway station construction has become increasingly diverse, and the terrain is becoming more complex. When a subway station or its ancillary structures are adjacent to a slope, firstly, during the foundation pit excavation stage, due to the large-scale unloading of the passive zone and considering the impact of slope overload in the active zone, the passive earth pressure cannot resist the active earth pressure on the slope side, posing a potential risk of deformation and instability to the foundation pit. Secondly, as an important public transportation facility with high passenger flow, subways require the slopes adjacent to them to remain stable throughout the station's construction and operation. This is especially true for subway stations located in urban core areas where land resources are scarce, and the slope side is often used as pedestrian walkways or vehicular roads, making slope stability even more crucial.

[0003] Currently, most slope protection schemes adopt gravity retaining walls or cantilever piles, which are independently set up. During the excavation stage of the foundation pit, the loss of earth pressure in the passive zone caused by soil unloading can easily lead to slippage and overturning of the retaining components. In addition, the amount of reinforced concrete used is large, the cost is high, and the construction period is long.

[0004] Therefore, it is necessary to invent a retaining structure and construction method adjacent to a subway station to strengthen the connection between the retaining structure and the station structure, so that the active earth pressure on the slope side can be effectively transmitted through the load-bearing components. This can not only ensure the stability of the station foundation pit and the slope itself during the excavation stage, but also serve as a pedestrian walkway or vehicle roadway under permanent operation conditions, saving land resource utilization, reducing construction and operation risks, and ensuring the safety of people's lives and property. Summary of the Invention

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of this invention is to provide a box-type retaining wall structure for subway stations, which aims to solve the problems existing in the prior art.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A box-type retaining wall structure for a subway station includes a slope, backfill soil for the station roof slab, a station capping beam, a station retaining structure, a station structure, and a retaining wall structure.

[0008] The backfill soil for the station roof is located on one side of the slope, and the top of the slope is higher than the top of the backfill soil for the station roof.

[0009] The station structure is located within the backfill soil of the station roof slab through the station enclosure structure, and the station capping beam is located on top of the station enclosure structure;

[0010] The retaining wall structure includes retaining wall side walls, retaining wall waist beams, retaining wall cross beams, retaining wall support beams, retaining wall bottom plates, retaining wall top plates, and retaining wall backfill material. The retaining wall side walls, retaining wall top plates, and retaining wall bottom plates are located within the soil of the slope. The retaining wall side walls, retaining wall top plates, and retaining wall bottom plates are connected to form a retaining wall cavity for placing the retaining wall backfill material. The retaining wall waist beams are located on the retaining wall side walls. The retaining wall cross beams are located within the retaining wall cavity via the retaining wall waist beams. The two ends of the retaining wall support beams are respectively connected to the retaining wall waist beams and the station cap beam. One end of the retaining wall bottom plate extends from the soil of the slope and is connected to the station cap beam.

[0011] Preferably, a pedestrian walkway or a driveway is provided at the top of the slope.

[0012] Preferably, the station enclosure structure is a retaining pile or a diaphragm wall, and the station enclosure structure is arranged around the perimeter of the station structure.

[0013] Preferably, the cross-sectional shape of the station cap beam is the same as that of the station enclosure structure, the top of the station enclosure structure is located inside the station cap beam, and the station cap beam is provided with a steel bar connector that is connected to one end of the retaining wall support beam and the retaining wall base plate.

[0014] Preferably, the top of the retaining wall waist beam is flush with the top of the backfill soil of the station roof slab;

[0015] The width of the retaining wall waist beam is the same as the width of the retaining wall side wall, and the retaining wall waist beam is embedded in the retaining wall side wall.

[0016] Alternatively, the width of the retaining wall waist beam may be greater than the width of the retaining wall side wall, and the retaining wall waist beam may protrude from the retaining wall side wall.

[0017] Preferably, the number of retaining wall beams is two or more and they are evenly distributed along the length of the retaining wall sidewall;

[0018] The retaining wall support beams are evenly distributed along the length of the retaining wall sidewall and correspond to the positions of the retaining wall crossbeams.

[0019] Preferably, a railing is provided at the top edge of the top slab of the retaining wall.

[0020] This invention also includes a construction method for a box-type retaining wall structure for subway stations, applied to the aforementioned box-type retaining wall structure for subway stations, comprising the following steps:

[0021] S1. Before the excavation of the subway station foundation pit, the slope is cut by sloping. If there is no sloping condition, temporary support is used to ensure the stability of the slope.

[0022] S2. Construction of the station enclosure structure around the station structure: First, set up the station enclosure structure, then set up the station capping beam, and connect the top of the station enclosure structure to the station capping beam. Reserve steel rebar connectors on the side of the station capping beam.

[0023] S3. At the location where the retaining wall base slab is set in the soil of the slope, foundation treatment is carried out, and the bearing capacity of the foundation is improved by dynamic compaction or replacement method.

[0024] S4. After the foundation treatment is completed, the retaining wall structure is poured from bottom to top: First, the steel bars of the retaining wall base plate are connected to the steel bar connectors of the station cap beam, then the retaining wall base plate is poured, and the first fixed support is formed by pouring the retaining wall base plate and the station cap beam.

[0025] S5. Complete the simultaneous binding of the reinforcing bars of the retaining wall sidewalls, retaining wall waist beams, and retaining wall cross beams, and pour concrete. Set up a reinforcing bar connector at the retaining wall waist beam. After the concrete strength reaches the design requirements, construct the retaining wall support beam: connect one end of the reinforcing bar of the retaining wall support beam to the reinforcing bar connector at the retaining wall waist beam, and connect the other end of the reinforcing bar to the reinforcing bar connector at the station cap beam. Pour the retaining wall support beam and the station cap beam to form a second fixed support.

[0026] S6. After the concrete strength of the retaining wall base slab, retaining wall side walls, retaining wall waist beams, retaining wall cross beams and retaining wall support beams reaches the design strength, retaining wall backfill material is installed in the retaining wall cavity. After the backfill height of the retaining wall backfill material reaches the design elevation, the retaining wall top slab is poured.

[0027] S7. After the above steps are completed, the station foundation pit is excavated. During the excavation process, the deformation and settlement of the station retaining structure and retaining wall structure are monitored. After the station structure is completed, the top slab is covered with soil to form the station roof backfill. The road structure on the top of the retaining wall and the slope is restored, and the railings are installed.

[0028] Preferably, in step S3, a 50mm thick C20 plain concrete cushion layer is provided below the base plate of the retaining wall.

[0029] Preferably, in step S6, the backfill height of the retaining wall backfill material is determined based on the design elevation: according to the calculation of the retaining wall's anti-sliding and anti-overturning properties, referring to the "Technical Specification for Foundation Pit Support JGJ 120-2012", the anti-sliding stability safety factor is greater than or equal to 1.2, and the anti-overturning safety factor is greater than or equal to 1.3.

[0030] Compared with the prior art, the beneficial effects of the present invention include:

[0031] The subway station box-type retaining wall structure proposed in this application, combined with the construction method, can form an effective force transmission path, with reliable node connections, strong bearing capacity, and simple and feasible construction method. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a frontal view of the internal structure of the subway station box-type retaining wall according to the present invention.

[0034] Figure 2 This is a top-view internal schematic diagram of the box-type retaining wall structure for subway stations according to the present invention.

[0035] Figure 3 for Figure 1 A schematic diagram of the method for marking A.

[0036] in:

[0037] 1-Slope, 2-Backfill soil for station roof, 3-Station capping beam, 4-Station retaining structure, 5-Station structure, 6-Side wall of retaining wall, 7-Waist beam of retaining wall, 8-Horizontal beam of retaining wall, 9-Support beam of retaining wall, 10-Bottom slab of retaining wall, 11-Top slab of retaining wall, 12-Backfill material of retaining wall, 13-Guardrail. Detailed Implementation

[0038] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. Many specific details are set forth in the following description to provide a thorough understanding of the present invention; the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0040] Example:

[0041] See Figures 1-3 A box-type retaining wall structure for a subway station includes a slope 1, backfill soil for the station roof slab 2, a station capping beam 3, a station retaining structure 4, a station structure 5, and a retaining wall structure.

[0042] The station roof backfill soil 2 is located on one side of the slope 1, and the top of the slope 1 is higher than the top of the station roof backfill soil 2.

[0043] The station structure 5 is located within the soil of the station roof backfill 2 via the station retaining structure 4, and the station capping beam 3 is located on top of the station retaining structure 4.

[0044] The retaining wall structure includes retaining wall side walls 6, retaining wall waist beams 7, retaining wall cross beams 8, retaining wall support beams 9, retaining wall bottom plates 10, retaining wall top plates 11, and retaining wall backfill material 12. The retaining wall side walls 6, retaining wall top plates 11, and retaining wall bottom plates 10 are located in the soil of the slope 1. The retaining wall side walls 6, retaining wall top plates 11, and retaining wall bottom plates 10 are connected to form a retaining wall cavity for placing the retaining wall backfill material 12. The retaining wall waist beams 7 are located in the retaining wall side walls 6. The retaining wall cross beams 8 are located in the retaining wall cavity through the retaining wall waist beams 7. The two ends of the retaining wall support beams 9 are connected to the retaining wall waist beams 7 and the station cap beams 3, respectively. One end of the retaining wall bottom plates 10 extends from the soil of the slope 1 and is connected to the station cap beams 3.

[0045] In this embodiment, a pedestrian walkway or a driveway is provided at the top of the slope 1.

[0046] In this embodiment, the station enclosure structure 4 is either a retaining pile or a diaphragm wall, and the station enclosure structure 4 is set around the station structure 5. When it is a retaining pile structure, its diameter can be selected as 800mm or 1000mm, and when it is a diaphragm wall structure, its thickness can be selected as 800mm or 1000mm.

[0047] In this embodiment, the cross-sectional shape of the station capping beam 3 is the same as that of the station enclosure structure 4. The top of the station enclosure structure 4 is located inside the station capping beam 3. The station capping beam 3 is equipped with a steel bar connector that connects to one end of the retaining wall support beam 9 and the retaining wall base plate 10. More specifically, the station capping beam 3 is made of C35 concrete and has the following dimensions: width 1000mm and height 800mm. The top of the station enclosure structure 4 extends 100mm into the station capping beam 3, and the main reinforcement bars at the top of the station enclosure structure 4 are anchored into the station capping beam 3. This strengthens the restraint effect at the top of the station enclosure structure 4.

[0048] In this embodiment, the top of the retaining wall waist beam 7 is flush with the top of the backfill soil 2 of the station roof slab; the retaining wall waist beam 7 is made of C35 concrete and has the following dimensions: width 400mm to 600mm and height 500mm to 800mm.

[0049] There are two specific width dimensions:

[0050] The first type: the width of the retaining wall waist beam 7 is the same as the width of the retaining wall side wall 6, and the retaining wall waist beam 7 is embedded in the retaining wall side wall 6.

[0051] The second type: the width of the retaining wall waist beam 7 is greater than the width of the retaining wall side wall 6, and the retaining wall waist beam 7 protrudes out of the retaining wall side wall 6.

[0052] In this embodiment, the retaining wall beam 8 is made of C35 concrete and has the following dimensions: width 500mm to 800mm and height 500mm to 800mm. There are two or more beams and they are evenly distributed along the length of the retaining wall sidewall 6. Specifically, one retaining wall beam 8 is set every 3m to 5m. At the same time, the height of the retaining wall beam 8 is the same as that of the retaining wall waist beam 7. The steel bars at both ends of the retaining wall beam 8 are anchored into the retaining wall waist beam 7 to form a force transmission component.

[0053] In this embodiment, the retaining wall support beam 9 is made of C35 concrete, and its width is the same as that of the retaining wall waist beam 7. The retaining wall support beam 9 is evenly distributed along the length of the retaining wall side wall 6 and corresponds to the position of the retaining wall cross beam 8. The steel bars at one end of the retaining wall support beam 9 are anchored into the retaining wall waist beam 7 and rigidly connected to the retaining wall waist beam 7; the steel bars at the other end are rigidly connected to the station cap beam 3 through the steel bar connector reserved on the side of the station cap beam 3, forming a force transmission component.

[0054] In this embodiment, the retaining wall base plate 10 is made of C35 concrete with a thickness of 300mm to 500mm. Its width is the sum of the overall width of the retaining wall structure and the distance from the retaining wall structure to the side of the station capping beam 3. The retaining wall base plate 10 is rigidly connected to the station capping beam 3 via pre-installed steel reinforcement connectors on the side of the station capping beam 3. The connection structure between the retaining wall support beam 9, the retaining wall base plate 10, and the station capping beam 3 can be found in [reference needed]. Figure 3 .

[0055] In this embodiment, the retaining wall top plate 11 is made of C35 concrete with a thickness of 200mm to 300mm. The elevation of the retaining wall top plate 11 is the same as the top elevation of the slope 1. The retaining wall top plate 11 can be used as a pedestrian walkway or a vehicle roadway. There are 13 railings at the top edge of the retaining wall top plate 11. Specifically, the railings 13 are fixed to the retaining wall top plate 11 with anchor bolts. If the retaining wall top plate 11 is used as a vehicle roadway, a crash barrier should also be added.

[0056] In this embodiment, the backfill material 12 of the retaining wall is well-graded sand. The backfill elevation is determined based on the calculation of the retaining wall's resistance to sliding and overturning, and should not be less than the top elevation of the retaining wall beam 8.

[0057] This invention also includes a construction method for a box-type retaining wall structure for subway stations, applicable to the aforementioned box-type retaining wall structure for subway stations, comprising the following steps:

[0058] S1. Before the excavation of the subway station foundation pit, slope 1 is cut by sloping. If there is no sloping condition, temporary support is used to ensure the stability of slope 1.

[0059] S2. Construction of station enclosure structure 4 around station structure 5: First, set up station enclosure structure 4, then set up station capping beam 3, and connect the top of station enclosure structure 4 to station capping beam 3. Reserve steel rebar connectors on the side of station capping beam 3.

[0060] S3. At the location where the retaining wall base plate 10 is set in the soil of slope 1, foundation treatment is carried out, and the bearing capacity of the foundation is improved by dynamic compaction or replacement method.

[0061] S4. After the foundation treatment is completed, the retaining wall structure is poured from bottom to top: First, the steel bars of the retaining wall base plate 10 are connected to the steel bar connectors of the station capping beam 3, then the retaining wall base plate 10 is poured, and the first fixed support is formed by pouring it together with the station capping beam 3.

[0062] S5. Simultaneously tie and pour concrete for the reinforcing bars of the retaining wall sidewall 6, retaining wall waist beam 7, and retaining wall cross beam 8. Install a reinforcing bar connector at the retaining wall waist beam 7. After the concrete strength reaches the design requirements, construct the retaining wall support beam 9: connect one end of the reinforcing bar of the retaining wall support beam 9 to the reinforcing bar connector at the retaining wall waist beam 7, and connect the other end of the reinforcing bar to the reinforcing bar connector at the station cap beam 3. Pour the retaining wall support beam 9 and the station cap beam 3 to form a second fixed support.

[0063] S6. After the concrete strength of the retaining wall base plate 10, retaining wall side wall 6, retaining wall waist beam 7, retaining wall cross beam 8 and retaining wall support beam 9 reaches the design strength, retaining wall backfill material 12 is installed in the retaining wall cavity. After the backfill height of the retaining wall backfill material 12 reaches the design elevation, the retaining wall top plate 11 is poured.

[0064] S7. After the above steps are completed, the station foundation pit is excavated. During the excavation process, the deformation and settlement of the station retaining structure 4 and the retaining wall structure are monitored. After the station structure 5 is completed, the top slab is covered with soil to form the station top slab backfill soil 2. The road structure on the top of the retaining wall top slab 11 and the slope 1 is restored, and the railing 13 is installed.

[0065] Specifically, in step S3, a 50mm thick C20 plain concrete cushion layer is set below the retaining wall base plate 10.

[0066] Specifically, in step S6, the backfill height of the retaining wall backfill material 12 is determined by reference to the design elevation: based on the anti-sliding and anti-overturning calculations of the retaining wall, referring to the "Technical Specification for Foundation Pit Support JGJ 120-2012", the anti-sliding stability safety factor is greater than or equal to 1.2, and the anti-overturning safety factor is greater than or equal to 1.3.

[0067] This embodiment employs a rigid connection structure between the station capping beam 3 and the station retaining structure 4, increasing overall rigidity and forming a fixed support structure. The retaining wall base plate 10 is then rigidly connected to the station capping beam 3. Retaining wall waist beams 7 and support beams are installed to strengthen the bottom constraint of the retaining wall structure. Simultaneously, the active earth pressure of the slope 1 corresponding to the retaining wall structure is transmitted to the station capping beam 3 through the retaining wall base plate 10, retaining wall waist beams 7, and retaining wall support beams 9, reducing the cantilever length of the retaining wall structure. The overall force transmission path is clear. Retaining wall backfill material 12 is installed within the retaining wall structure to increase its self-weight, improving its resistance to sliding and overturning, ensuring stability and safety. The retaining wall structure can meet the stress requirements of pedestrian walkways or driveways, exhibiting good overall stability. The entire construction method is rationally designed, simple and feasible, safe and reliable, and easy to construct.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A box-type retaining wall structure for a subway station, characterized in that, This includes slopes, station roof backfill, station capping beams, station retaining structures, station structures, and retaining wall structures; The backfill soil for the station roof is located on one side of the slope, and the top of the slope is higher than the top of the backfill soil for the station roof. The station structure is located within the backfill soil of the station roof slab through the station enclosure structure, and the station capping beam is located on top of the station enclosure structure; The retaining wall structure includes retaining wall side walls, retaining wall waist beams, retaining wall cross beams, retaining wall support beams, retaining wall bottom plates, retaining wall top plates, and retaining wall backfill material. The retaining wall side walls, retaining wall top plates, and retaining wall bottom plates are located within the soil of the slope. The retaining wall side walls, retaining wall top plates, and retaining wall bottom plates are connected to form a retaining wall cavity for placing the retaining wall backfill material. The retaining wall waist beams are located on the retaining wall side walls. The retaining wall cross beams are located within the retaining wall cavity via the retaining wall waist beams. The two ends of the retaining wall support beams are respectively connected to the retaining wall waist beams and the station cap beam. One end of the retaining wall bottom plate extends from the soil of the slope and is connected to the station cap beam.

2. The box-type retaining wall structure for subway stations according to claim 1, characterized in that, A pedestrian walkway or vehicle lane is provided at the top of the slope.

3. The box-type retaining wall structure for subway stations according to claim 1, characterized in that, The station enclosure structure is a retaining pile or a diaphragm wall, and the station enclosure structure is set around the perimeter of the station structure.

4. The subway station box-type retaining wall structure according to claim 3, characterized in that, The cross-sectional shape of the station cap beam is the same as that of the station enclosure structure. The top of the station enclosure structure is located inside the station cap beam. The station cap beam is equipped with a steel bar connector that is connected to one end of the retaining wall support beam and the retaining wall base plate.

5. The box-type retaining wall structure for subway stations according to claim 1, characterized in that, The top of the retaining wall waist beam is flush with the top of the backfill soil of the station roof slab; The width of the retaining wall waist beam is the same as the width of the retaining wall side wall, and the retaining wall waist beam is embedded in the retaining wall side wall. Alternatively, the width of the retaining wall waist beam may be greater than the width of the retaining wall side wall, and the retaining wall waist beam may protrude from the retaining wall side wall.

6. The box-type retaining wall structure for subway stations according to claim 5, characterized in that, The number of retaining wall beams is two or more and they are evenly distributed along the length of the retaining wall sidewall. The retaining wall support beams are evenly distributed along the length of the retaining wall sidewall and correspond to the positions of the retaining wall crossbeams.

7. The box-type retaining wall structure for subway stations according to claim 1, characterized in that, A railing is provided at the top edge of the top slab of the retaining wall.

8. A construction method for a box-type retaining wall structure for a subway station, characterized in that, The method applied to the box-type retaining wall structure for subway stations according to any one of claims 1-7 includes the following steps: S1. Before the excavation of the subway station foundation pit, the slope is cut by sloping. If there is no sloping condition, temporary support is used to ensure the stability of the slope. S2. Construction of the station enclosure structure around the station structure: First, set up the station enclosure structure, then set up the station capping beam, and connect the top of the station enclosure structure to the station capping beam. Reserve steel rebar connectors on the side of the station capping beam. S3. At the location where the retaining wall base slab is set in the soil of the slope, foundation treatment is carried out, and the bearing capacity of the foundation is improved by dynamic compaction or replacement method. S4. After the foundation treatment is completed, the retaining wall structure is poured from bottom to top: First, the steel bars of the retaining wall base plate are connected to the steel bar connectors of the station cap beam, then the retaining wall base plate is poured, and the first fixed support is formed by pouring the retaining wall base plate and the station cap beam. S5. Complete the simultaneous binding of the reinforcing bars of the retaining wall sidewalls, retaining wall waist beams, and retaining wall cross beams, and pour concrete. Set up a reinforcing bar connector at the retaining wall waist beam. After the concrete strength reaches the design requirements, construct the retaining wall support beam: connect one end of the reinforcing bar of the retaining wall support beam to the reinforcing bar connector at the retaining wall waist beam, and connect the other end of the reinforcing bar to the reinforcing bar connector at the station cap beam. Pour the retaining wall support beam and the station cap beam to form a second fixed support. S6. After the concrete strength of the retaining wall base slab, retaining wall side walls, retaining wall waist beams, retaining wall cross beams and retaining wall support beams reaches the design strength, retaining wall backfill material is installed in the retaining wall cavity. After the backfill height of the retaining wall backfill material reaches the design elevation, the retaining wall top slab is poured. S7. After the above steps are completed, the station foundation pit is excavated. During the excavation process, the deformation and settlement of the station retaining structure and retaining wall structure are monitored. After the station structure is completed, the top slab is covered with soil to form the station roof backfill. The road structure on the top of the retaining wall and the slope is restored, and the railings are installed.

9. The construction method for the box-type retaining wall structure of a subway station according to claim 8, characterized in that, In step S3, a 50mm thick C20 plain concrete cushion layer is set below the base plate of the retaining wall.

10. The construction method of the box-type retaining wall structure for subway stations according to claim 8, characterized in that, In step S6, the backfill height of the retaining wall backfill material is determined based on the design elevation: according to the calculation of the retaining wall's anti-sliding and anti-overturning properties, referring to the "Technical Specification for Foundation Pit Support JGJ 120-2012", the anti-sliding stability safety factor is greater than or equal to 1.2, and the anti-overturning safety factor is greater than or equal to 1.3.

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