Prefabricated sandwich support retaining wall and construction method thereof

Abstract

The present application relates to the field of foundation pit support, and the purpose of the present application is to provide a prefabricated sandwich support retaining wall and a construction method thereof, comprising a plurality of H-shaped steel, the H-shaped steel is arranged along the slope bottom edge in sequence and interval, and the opening is arranged oppositely, the opposite opening between the two adjacent H-shaped steel forms an excavation area; a plurality of front retaining walls are inserted in each excavation area; a connecting rail is fixedly arranged on the rear side of the H-shaped steel; a plurality of L-shaped rear supports are arranged at the bottom of the rear retaining wall, the front side of the L-shaped rear support is provided with a positioning embedded part, and the bottom of the connecting part is inserted and matched with the positioning embedded part; a plurality of rear retaining walls are arranged behind the front retaining wall, and the rear retaining wall is pre-buried with a connecting part, which is inserted and matched with the connecting rail; the sandwich area is formed between the front retaining wall and the rear retaining wall, the rear side of the front retaining wall is provided with a first reinforcing rib, the front side of the rear retaining wall is provided with a second reinforcing rib, and the sandwich area is poured with concrete. The present application does not need to support the formwork on site, has high construction efficiency, good combination of prefabricated retaining wall and post-poured concrete, and good overall supporting capacity.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support, specifically to a prefabricated sandwich retaining wall and its construction method. Background Technology

[0002] In foundation pit and slope protection engineering, retaining wall structures are commonly used to resist lateral soil pressure and prevent slope collapse. Currently, the most commonly used retaining wall types in engineering include cast-in-place reinforced concrete retaining walls, prefabricated retaining walls, and composite concrete retaining walls.

[0003] Cast-in-place reinforced concrete retaining walls typically require the erection of large-area formwork within the foundation pit and the pouring of concrete. The construction process for this type of retaining wall is complex and time-consuming, with high requirements for construction space and site conditions. Furthermore, the installation and removal of formwork pose certain safety risks, making it unsuitable for construction in narrow spaces or under conditions of simultaneous support and excavation.

[0004] Existing precast retaining wall panels are mostly single-layer structures. Precast retaining wall panels lack secondary pouring, resulting in weak support capacity and limited stability, making it difficult to meet the support requirements for greater depths or higher safety levels.

[0005] Existing concrete composite retaining walls still require the installation and removal of formwork, failing to fully utilize the high construction efficiency of precast components. Furthermore, the bonding between concrete and precast components is limited, and the integration between different components is poor, resulting in overall weak load-bearing capacity. In addition, existing concrete composite retaining walls primarily rely on their own weight and backfill soil to resist lateral earth pressure, which has limited lateral earth pressure resistance and insufficient structural stability, especially noticeable on high slopes or in complex geological conditions. Summary of the Invention

[0006] The purpose of this invention is to provide a precast sandwich retaining wall and its construction method, which eliminates the need for on-site formwork, has high construction efficiency, and exhibits good bonding between the precast retaining wall and the post-cast concrete, thus possessing excellent resistance to lateral earth pressure and overall support capabilities.

[0007] One of the objectives of this invention is achieved through the following technical solution: A prefabricated sandwich retaining wall includes: Several H-beams are vertically inserted into the soil. The H-beams are arranged sequentially at intervals along the bottom edge of the slope, with their openings facing each other. An excavation zone is formed between the openings of two adjacent H-beams. Several retaining walls are inserted one-to-one in each excavation area, with the front side of the retaining wall corresponding to the slope. A connecting rail is fixed to the rear side of the H-beam; Several rear retaining walls are arranged horizontally and parallel to the front retaining wall behind it. Connectors are pre-embedded in the rear retaining walls and are inserted into the connecting rails. Several L-shaped rear supports are installed at the bottom of each rear retaining wall. The front side of each L-shaped rear support is provided with a positioning embedded part. The positioning embedded part is located below the connecting rail. The bottom of the connecting part is inserted and matched with the positioning embedded part through the connecting rail. The front retaining wall and the rear retaining wall form a sandwich area. The rear side of the front retaining wall is provided with several first reinforcing ribs located in the sandwich area, and the front side of the rear retaining wall is provided with several second reinforcing ribs located in the sandwich area. The first and second reinforcing ribs are staggered. The sandwich area is filled with concrete.

[0008] The second objective of this invention is achieved through the following technical solution: A construction method for a precast sandwich retaining wall includes the following steps: Step S1: Insert several H-beams at intervals along the bottom edge of the slope, so that the side of the H-beam with the connecting rail is away from the slope, and each H-beam is located at the same horizontal elevation, with its openings facing each other. Step S2: Excavate a space in the excavation area to accommodate the bottom of the front retaining wall, hoist the front retaining wall above the excavation area, so that the bottom of the front retaining wall fits against the web of the H-beams on both sides and is placed into the space. Step S3: Excavate the soil behind the front retaining wall in layers according to the design plan. Each time a layer of soil is excavated, the top surface of that layer is used as the new working surface. Excavate the soil below the front retaining wall in the excavation area so that the front retaining wall slides down layer by layer along the web of the H-beams on both sides until the front retaining wall falls to the design position. Step S4: Hoist the back retaining walls in sequence, align the connectors on each back retaining wall with the connecting rails on the back of the corresponding H-beams, and lower each back retaining wall along the corresponding connecting rails. Leave an installation space between the bottom of each back retaining wall and the construction surface for the L-shaped back support to be inserted. Step S5: Place each L-shaped back support into the installation space at the bottom of the corresponding back retaining wall in sequence, and anchor the L-shaped back support into the soil. Continue to lower the corresponding back retaining wall, so that the bottom of the connector is inserted into the positioning embedded part on the front side of the corresponding L-shaped back support, and ensure that the protrusion and groove between two adjacent back retaining walls are aligned with each other to complete the lateral splicing between adjacent back retaining walls. Step S6: After the rear retaining wall is installed in place, the first reinforcing rib and the second reinforcing rib are staggered. Concrete is poured into the sandwich area and vibrated to compact it. Construction is completed after the concrete strength reaches the design requirements.

[0009] Compared with the prior art, the advantages of the present invention are as follows: 1. By inserting the front retaining wall into the excavation area and using a layered excavation construction method, the front retaining wall slides down layer by layer along the web of the H-shaped steel during the soil excavation process, achieving the construction effect of excavation and support at the same time. Through the insertion and cooperation of the connector and the connecting rail, the rear retaining wall can be guided down along the connecting rail. During the descent, the bottom of the connector is inserted and cooperated with the positioning embedded part on the front side of the L-shaped rear support, thereby connecting the rear retaining wall with the L-shaped rear support. At the same time, after the L-shaped rear support is anchored into the soil, it can form a support on the back slope side of the rear retaining wall, bearing and dispersing the lateral earth pressure from the slope soil, thereby enhancing the ability of the retaining wall to resist lateral earth pressure and reducing the risk of the retaining wall tilting or sliding under stress. In addition, a sandwich area is formed between the front retaining wall and the rear retaining wall, and the first reinforcing rib and the second reinforcing rib are misaligned within the sandwich area. The rear retaining wall directly serves as a permanent, non-removable formwork, and concrete is poured into the sandwich area. This allows the cured concrete to form an interlocking structure with the first and second reinforcing ribs, thereby significantly enhancing the bonding effect between the post-cast concrete and the precast retaining wall, and improving the overall shear resistance and long-term structural stability of the retaining wall. Attached Figure Description

[0010] Figure 1 This is a top view of a prefabricated sandwich retaining wall embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the front retaining wall of the present invention; Figure 3 This is a schematic diagram of the structure of the H-beam and connecting rail of the present invention; Figure 4 This is a schematic diagram of the structure of the rear retaining wall of the present invention; Figure 5 This is a structural schematic diagram of an embodiment of a prefabricated sandwich retaining wall according to the present invention; Figure 6 This is a schematic diagram of the L-shaped rear support structure of the present invention; Figure 7 This is a schematic diagram of the cooperation between the L-shaped rear support and the rear retaining wall of the present invention.

[0011] Labeling Explanation: 1 H-beam, 2 Excavation Zone, 3 Front Retaining Wall, 30 First Reinforcing Rib, 4 Connecting Rail, 41 L-shaped Angle Steel, 42 T-shaped Slot, 5 Rear Retaining Wall, 50 Connector, 51 Second Reinforcing Rib, 52 Protrusion, 53 Groove, 6 Sandwich Area, 7 L-shaped Rear Support, 71 First Side Plate, 72 Second Side Plate, 73 Reinforcing Steel Bar, 8 Positioning Embedded Part, 81 Positioning Slot. Detailed Implementation

[0012] The present invention will now be described in detail with reference to the accompanying drawings and embodiments: like Figure 1-7The diagram shown is a schematic representation of an embodiment of a prefabricated sandwich retaining wall provided by the present invention: A prefabricated sandwich retaining wall includes: Several H-beams 1 are vertically inserted into the soil layer. The H-beams 1 are arranged sequentially at intervals along the bottom edge of the slope, and their openings are arranged opposite each other. An excavation zone 2 is formed between the opposite openings of two adjacent H-beams 1. Several front retaining walls 3 are inserted one-to-one in each excavation zone 2, with the front side of the front retaining wall 3 corresponding to the slope. Connecting rail 4 is fixed to the rear side of the H-beam 1; Several rear retaining walls 5 are arranged horizontally and parallel to the front retaining wall 3 behind it. The rear retaining walls 5 are pre-embedded with connectors 50, which are inserted into the connecting rails 4. Several L-shaped rear supports 7 are correspondingly installed at the bottom of each rear retaining wall 5. The front side of the L-shaped rear support 7 is provided with a positioning embedded part 8. The positioning embedded part 8 is located below the connecting rail 4. The bottom of the connecting part 50 is inserted and matched with the positioning embedded part 8 through the connecting rail 4. The front retaining wall 3 and the rear retaining wall 5 form a sandwich area 6. The rear side of the front retaining wall 3 is provided with a number of first reinforcing ribs 30 located in the sandwich area 6, and the front side of the rear retaining wall 5 is provided with a number of second reinforcing ribs 51 located in the sandwich area 6. The first reinforcing ribs 30 and the second reinforcing ribs 51 are arranged in a staggered manner, and concrete is poured in the sandwich area 6.

[0013] Specifically, the front retaining wall 3, the rear retaining wall 5, and the L-shaped rear support 7 are all prefabricated reinforced concrete components.

[0014] The L-shaped rear support 7 includes a horizontally arranged first side plate 71 and a vertically arranged second side plate 72. The first side plate 71 is located at the bottom of the rear retaining wall 5, and the second side plate 72 is connected to the bottom of the rear end of the first side plate 71 and is used to anchor into the soil. The positioning embedded part 8 is located on the front side of the first side plate 71.

[0015] The positioning embedded part 8 has a positioning slot 81, and the bottom of the connector 50 is inserted into the positioning slot 81.

[0016] Furthermore, a number of horizontally spaced reinforcing steel bars 73 are pre-embedded in the L-shaped rear support 7, and one end of the reinforcing steel bar 73 passes through the front end of the L-shaped rear support 7 and extends into the sandwich area 6.

[0017] The first reinforcing rib 30 is a longitudinally extending strip structure, and the first reinforcing rib 30 is integrally formed with the front retaining wall 3; The second reinforcing rib 51 is a longitudinally extending strip structure, and the second reinforcing rib 51 is integrally formed with the rear retaining wall 5.

[0018] The connecting rail 4 includes two longitudinally extending and laterally spaced L-shaped angle steels 41; One side of each of the two L-shaped angle steels 41 is welded and fixed to the rear side of the H-shaped steel 1, and the other side of each of the two L-shaped angle steels 41 is arranged opposite to each other, forming a T-shaped slot 42 between the two L-shaped angle steels 41 and the H-shaped steel 1; The rear end of the connector 50 is embedded in the rear retaining wall 5, and its front end is a T-shaped structure that matches the T-shaped slot 42.

[0019] The rear end of the connector 50 is embedded in the middle of the rear retaining wall 5.

[0020] Furthermore, the connector 50 is an I-beam, and the rear end of the rear flange and part of the web of the I-beam are pre-embedded in the rear retaining wall 5.

[0021] One side of the rear retaining wall 5 is provided with a protrusion 52, and the other side of the rear retaining wall 5 is provided with a groove 53 that matches the protrusion 52. Two adjacent rear retaining walls 5 are horizontally spliced ​​through the protrusion 52 and the groove 53.

[0022] Cement mortar is used to fill the joint at the rear side of two adjacent rear retaining walls 5. Specifically, the cement mortar used is the same grade as that used for the rear retaining walls 5.

[0023] A construction method for the above-mentioned prefabricated sandwich retaining wall includes the following steps: Step S1: Insert several H-beams 1 at intervals along the bottom edge of the slope, so that the side of the H-beam 1 with the connecting rail 4 is away from the slope, and each H-beam 1 is located at the same horizontal elevation, with its openings facing each other. Step S2: Excavate downwards in the excavation area 2 to create a space that can accommodate the bottom of the front retaining wall 3. Hoist the front retaining wall 3 above the excavation area 2 so that the bottom of the front retaining wall 3 fits against the web of the H-beams 1 on both sides and is placed into the space. Step S3: Excavate the soil behind the front retaining wall 3 in layers according to the design plan. Each time a layer of soil is excavated, the top surface of that layer is used as the new working surface. Excavate the soil below the front retaining wall 3 into the excavation area 2, so that the front retaining wall 3 slides down layer by layer along the web of the H-beams 1 on both sides until the front retaining wall 3 falls to the design position. Step S4: Hoist the rear retaining walls 5 in sequence, align the connectors 50 on each rear retaining wall 5 with the connecting rails 4 on the back side of the corresponding H-beam 1, so that each rear retaining wall 5 falls along the corresponding connecting rails 4, and reserve an installation space between the bottom of each rear retaining wall 5 and the construction surface for the L-shaped rear support 7 to be placed. Step S5: Place each L-shaped rear support 7 into the installation space at the bottom of the corresponding rear retaining wall 5 in sequence, and anchor the L-shaped rear support 7 into the soil. Continue to lower the corresponding rear retaining wall 5 so that the bottom of the connector 50 is inserted into the positioning embedded part 8 on the front side of the corresponding L-shaped rear support 7, and ensure that the protrusion 52 and the groove 53 between two adjacent rear retaining walls 5 are aligned with each other to complete the lateral splicing between adjacent rear retaining walls 5. Step S6: After the rear retaining wall 5 is installed in place, the first reinforcing rib 30 and the second reinforcing rib 51 are staggered and concrete is poured into the sandwich area 6 and vibrated to compact it. After the concrete strength reaches the design requirements, the construction is completed.

[0024] The principle of this invention, a prefabricated sandwich retaining wall and its construction method, is roughly as follows: During the layered excavation of the soil in excavation zone 2, the front retaining wall 3 slides down layer by layer along the web of the H-beam 1, forming the initial retaining support for simultaneous construction and support. Subsequently, the rear retaining wall 5 is aligned and inserted with the connecting rail 4 on the rear side of the H-beam 1 using pre-embedded connectors 50, allowing the rear retaining wall 5 to fall vertically along the connecting rail 4 during hoisting. When the rear retaining wall 5 falls to the point where an installation space for the L-shaped rear support 7 is reserved between its bottom and the construction surface, the L-shaped rear support 7 is placed into the installation space and anchored into the soil. The rear retaining wall 5 continues to be lowered, so that the bottom of the connector 50 is inserted into the positioning pre-embedded part 8 on the front side of the L-shaped rear support 7, thus forming an insertion positioning structure between the lower part of the rear retaining wall 5 and the L-shaped rear support 7. After the L-shaped rear support 7 is anchored into the soil, it can form a rearward support on the back slope side of the rear retaining wall 5, bearing and dispersing the lateral earth pressure from the slope soil, reducing the risk of the rear retaining wall 5 tilting or sliding under stress.

[0025] After the rear retaining wall 5 is in place, the first reinforcing rib 30 on the rear side of the front retaining wall 3 and the second reinforcing rib 51 on the front side of the rear retaining wall 5 naturally form a misaligned state within the sandwich area 6. The rear retaining wall 5 directly serves as a permanent, non-removable formwork, and concrete is poured into the sandwich area 6. The cured concrete forms an interlocking structure with the first reinforcing rib 30 and the second reinforcing rib 51. Simultaneously, the reinforcing steel bars 73 within the L-shaped rear support 7 extend into the sandwich area 6 and are connected to the retaining wall through the concrete poured within the sandwich area 6, effectively enhancing the integrity between the precast components, the post-cast concrete, and the L-shaped rear support 7, thereby improving the overall shear strength and long-term stability of the retaining wall.

[0026] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A prefabricated sandwich retaining wall, characterized in that, include: Several H-beams (1) are vertically inserted into the soil. The H-beams (1) are arranged sequentially at intervals along the bottom edge of the slope, and their openings are set opposite each other. An excavation area (2) is formed between the relative openings of two adjacent H-beams (1). Several front retaining walls (3) are inserted one by one in each excavation area (2), and the front side of the front retaining wall (3) corresponds to the slope; The connecting rail (4) is fixed to the rear side of the H-beam (1); Several rear retaining walls (5) are arranged horizontally and parallel to the front retaining wall (3) behind it. Connecting parts (50) are pre-embedded on the rear retaining walls (5). The connecting parts (50) are inserted into the connecting rail (4). Several L-shaped rear supports (7) are provided at the bottom of each rear retaining wall (5). The front side of the L-shaped rear support (7) is provided with a positioning embedded part (8). The positioning embedded part (8) is located below the connecting rail (4). The bottom of the connector (50) is inserted and matched with the positioning embedded part (8) through the connecting rail (4). The front retaining wall (3) and the rear retaining wall (5) form a sandwich area (6). The rear side of the front retaining wall (3) is provided with a number of first reinforcing ribs (30) located in the sandwich area (6). The front side of the rear retaining wall (5) is provided with a number of second reinforcing ribs (51) located in the sandwich area (6). The first reinforcing ribs (30) and the second reinforcing ribs (51) are arranged in a staggered manner. The sandwich area (6) is filled with concrete.

2. The prefabricated sandwich retaining wall according to claim 1, characterized in that: The L-shaped rear support (7) includes a horizontally arranged first side plate (71) and a vertically arranged second side plate (72). The first side plate (71) is located at the bottom of the rear retaining wall (5), and the second side plate (72) is connected to the bottom of the rear end of the first side plate (71) and is used to anchor into the soil. The positioning embedded part (8) is located on the front side of the first side plate (71).

3. The prefabricated sandwich retaining wall according to claim 2, characterized in that: The positioning embedded part (8) is provided with a positioning slot (81), and the bottom of the connector (50) is inserted into the positioning slot (81).

4. The prefabricated sandwich retaining wall according to claim 2, characterized in that: The L-shaped rear support (7) is pre-embedded with several horizontally spaced reinforcing steel bars (73), one end of which passes through the front end of the L-shaped rear support (7) and extends into the sandwich area (6).

5. The prefabricated sandwich retaining wall according to claim 1, characterized in that: The first reinforcing rib (30) is a longitudinally extending strip structure, and the first reinforcing rib (30) is integrally formed with the front retaining wall (3); The second reinforcing rib (51) is a longitudinally extending strip structure, and the second reinforcing rib (51) is integrally formed with the rear retaining wall (5).

6. The prefabricated sandwich retaining wall according to claim 1, characterized in that: The connecting rail (4) includes two longitudinally extending and laterally spaced L-shaped angle steels (41). One side of each of the two L-shaped angle steels (41) is welded and fixed to the rear side of the H-shaped steel (1), and the other side of each of the two L-shaped angle steels (41) is arranged opposite to each other, forming a T-shaped slot (42) between the two L-shaped angle steels (41) and the H-shaped steel (1). The rear end of the connector (50) is embedded in the rear retaining wall (5), and its front end is a T-shaped structure that matches the T-shaped slot (42).

7. The prefabricated sandwich retaining wall according to claim 6, characterized in that: The rear end of the connector (50) is embedded in the middle of the rear retaining wall (5).

8. The prefabricated sandwich retaining wall according to claim 1, characterized in that: One side of the rear retaining wall (5) is provided with a protrusion (52), and the other side of the rear retaining wall (5) is provided with a groove (53) that matches the protrusion (52). Two adjacent rear retaining walls (5) are horizontally spliced ​​through the protrusion (52) and the groove (53).

9. The prefabricated sandwich retaining wall according to claim 8, characterized in that: Cement mortar is used to fill the joint at the rear side of the two adjacent rear retaining walls (5).

10. A construction method for a prefabricated sandwich retaining wall according to claim 8, characterized in that, Includes the following steps: Step S1: Insert several H-beams (1) at intervals along the bottom edge of the slope, so that the side of the H-beam (1) with the connecting rail (4) is away from the slope, and each H-beam (1) is located at the same horizontal elevation and its openings are arranged opposite each other; Step S2: Excavate downwards in the excavation area (2) to create a space that can accommodate the bottom of the front retaining wall (3), hoist the front retaining wall (3) above the excavation area (2), so that the bottom of the front retaining wall (3) fits against the web of the H-beams (1) on both sides and is placed into the space. Step S3: Excavate the soil behind the front retaining wall (3) in layers according to the design plan. Each time a layer of soil is excavated, the top surface of that layer of soil is used as a new working surface. Excavate the soil below the front retaining wall (3) in the excavation area (2) so that the front retaining wall (3) slides down layer by layer against the web of the H-beams (1) on both sides until the front retaining wall (3) falls to the design position. Step S4: Hoist the rear retaining walls (5) in sequence, align the connectors (50) on each rear retaining wall (5) with the connecting rails (4) on the back of the corresponding H-beam (1), so that each rear retaining wall (5) falls along the corresponding connecting rails (4), and reserve an installation space between the bottom of each rear retaining wall (5) and the construction surface for the L-shaped rear support (7) to be placed. Step S5: Place each L-shaped back support (7) into the installation space at the bottom of the corresponding back retaining wall (5) in sequence, and anchor the L-shaped back support (7) into the soil. Continue to lower the corresponding back retaining wall (5) so that the bottom of the connector (50) is inserted into the positioning embedded part (8) on the front side of the corresponding L-shaped back support (7), and ensure that the protrusion (52) and groove (53) between two adjacent back retaining walls (5) are aligned with each other to complete the lateral splicing between adjacent back retaining walls (5). Step S6: After the rear retaining wall (5) is installed in place, the first reinforcing rib (30) and the second reinforcing rib (51) are staggered and concrete is poured into the sandwich area (6) and vibrated to compact it. After the concrete strength reaches the design requirements, the construction is completed.

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