A foundation pit support structure

Abstract

The utility model belongs to the field of building construction technology discloses a kind of foundation pit support structure, including inner row pile and outer row pile, inner row pile and outer row pile are arranged at intervals, and inner row pile and outer row pile all include the multiple U-shaped steel sheet piles connected in order, and the two sides of U-shaped steel sheet pile are equipped with the lock catch of symmetrical arrangement, and the opening of adjacent two U-shaped steel sheet piles is arranged towards opposite direction, and adjacent two lock catches are mutually buckled and form insertion hole, and fixed column is inserted in insertion hole, and the upper portion of multiple fixed columns in inner row pile is connected with the upper portion of multiple fixed columns in outer row pile by connecting piece one-one.The utility model is connected with the stable connection and collaborative work of inner row pile and outer row pile by the combination design of U-shaped steel sheet pile, lock catch, fixed column and connecting piece, and the stability of foundation pit support is enhanced.The structure has the advantages of high waterproofness, reusability and simplified construction operation, and solves the problems of complex construction and resource waste in traditional support mode.

Description

Technical Field

[0001] This utility model belongs to the field of building construction technology, and in particular relates to a foundation pit support structure. Background Technology

[0002] Excavation pit support refers to temporary support, reinforcement, and groundwater control measures taken during the construction of underground main structures to ensure the safety of the surrounding environment. Support structures are typically used to support or reinforce the sidewalls of the excavation pit, and their quality directly affects the construction progress and safety of the entire excavation project. If the excavation pit support fails to meet requirements, it may lead to serious engineering accidents. With the gradual increase in the depth and scale of excavation pits, existing support methods face increasing challenges in design and construction, and traditional technologies have many problems.

[0003] Firstly, while slope excavation and simple support methods can select reasonable foundation pit slopes to ensure soil stability, this method requires a large amount of backfilling and is susceptible to rainy seasons, leading to localized collapses. Cement-soil gravity retaining structures form cement-soil piles through the mixing of cement and soil, possessing certain strength and stability, but are slow to construct, expensive, and difficult to apply effectively in soft soil areas. Soil nailing walls and composite soil nailing walls involve inserting soil nails and grouting after excavation to a certain depth, combined with steel mesh to form support; however, in areas with poor soil conditions, construction is difficult, requires significant equipment investment, and has strict time constraints. Steel sheet pile retaining structures can withstand soil and water pressure through the steel sheet piles, but their resistance to soil particles is insufficient; additional dewatering or water-blocking measures are needed when the groundwater level is high, and post-excavation deformation is significant. Cantilever pile wall retaining structures form a support structure through drilled cast-in-place piles; although they have high strength, they are expensive and have long construction periods. Diaphragm wall retaining structures utilize trenching machinery to create deep trenches and pour concrete. While offering high stability, their high cost and the need for specialized equipment increase construction difficulty. Furthermore, portal frame retaining structures, an optimization of cantilever retaining structures, alter the arrangement of the support structure, but suffer from high construction noise, low rigidity, poor repeatability, and a susceptibility to leakage.

[0004] In summary, existing foundation pit support technologies generally suffer from problems such as long construction periods, high costs, large deformations, water leakage, and high construction difficulty. In complex foundation pit construction environments, the limitations of traditional technologies become increasingly apparent. Therefore, there is an urgent need for a new, more efficient, lower-cost, easier-to-operate foundation pit support method that can ensure construction safety. Utility Model Content

[0005] This utility model provides a foundation pit support structure to solve existing technical problems.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this utility model is as follows:

[0007] A foundation pit support structure includes inner piles and outer piles, with the inner and outer piles spaced apart. Each inner and outer pile includes multiple U-shaped steel sheet piles connected in sequence. The two sides of each U-shaped steel sheet pile are provided with symmetrically arranged latches. The openings of two adjacent U-shaped steel sheet piles face opposite directions. Two adjacent latches interlock to form a insertion hole. A fixing column is inserted into the insertion hole. The upper parts of the multiple fixing columns in the inner piles are connected to the upper parts of the multiple fixing columns in the outer piles one by one through connectors.

[0008] As a further improvement to the above technical solution:

[0009] The connector includes a spring and a connector head. Both ends of the spring are provided with connector heads, and the connector heads are connected to the upper part of the fixed column.

[0010] The connector head is provided with a connecting hole, which is fitted onto the upper part of the fixing post. The upper part of the fixing post is provided with a fixing head, and the connecting hole is located below the fixing head.

[0011] Both the inner and outer rows of piles are provided with multiple diagonal braces, which are located on the inner side of the corners of the inner and outer rows of piles. The two ends of each diagonal brace are sleeved on the fixed head.

[0012] Starting from the corner, multiple fixing heads are arranged at the same interval on both sides. Two fixing heads with the same interval form a group, and two fixing heads in the same group are connected by diagonal braces.

[0013] The multiple diagonal braces are connected by connecting rods to form an integral structure.

[0014] The inner and outer rows of piles are also provided with multiple walers, which extend along the length of the inner or outer rows of piles, and each waler is connected to multiple fixed heads of unconnected diagonal braces.

[0015] The waler is provided with a groove that extends along the length of the waler and is engaged with multiple fixing heads.

[0016] The connectors are arranged in pairs and cross each other, and multiple sets of the connectors are distributed along the length of the inner or outer row of piles.

[0017] The insertion hole is a square hole, and the fixing post is a square post.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] The inner and outer rows of piles are connected sequentially by multiple U-shaped sheet piles, with the interlocking buckles of adjacent U-shaped sheet piles forming insertion holes. Fixed columns are inserted into these insertion holes, ensuring a tight connection and stability of the structure. Connectors link the upper parts of multiple fixed columns in both the inner and outer rows of piles, allowing the two rows of piles to work together, improving the overall structural stability, preventing soil slippage, and effectively enhancing waterproofing, especially in areas with high groundwater levels, effectively preventing leakage. Furthermore, all components, such as the fixed columns and connectors, are reusable, significantly reducing project costs and resource waste, meeting environmental and economic requirements. This design is simple and efficient, solving common problems in existing foundation pit support technologies such as poor stability, complex construction, and non-reusability. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a partial structural diagram of the foundation pit support structure.

[0022] Figure 2 This is a partial structural diagram of the inner row of piles.

[0023] Figure 3 This is a partial structural diagram of a U-shaped steel sheet pile.

[0024] Figure 4 This is a partial structural diagram of the fixed column.

[0025] Figure 5 This is a partial structural diagram of the connector.

[0026] Figure 6 This is a schematic diagram of a partial cross-section of the foundation pit support structure along its length.

[0027] Figure 7 This is a schematic diagram of the assembly structure of the diagonal brace and connecting rod.

[0028] Figure 8 This is a schematic diagram of a partial structure of the waler.

[0029] Legend:

[0030] 1. Inner row of piles; 11. U-shaped sheet piles; 12. Locking buckle; 13. Insertion hole; 14. Corner; 2. Outer row of piles; 3. Fixed column; 31. Fixed head; 4. Connector; 41. Spring; 42. Connector head; 43. Connecting hole; 5. Diagonal brace; 51. Connecting rod; 6. Waler; 61. Groove. Detailed Implementation

[0031] To facilitate understanding of this utility model, the following description will be provided in more comprehensive and detailed manner with reference to the accompanying drawings and preferred embodiments. However, the scope of protection of this utility model is not limited to the following specific embodiments.

[0032] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of protection of this invention.

[0033] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0034] Example: Figures 1-8 As shown, the foundation pit support structure of this embodiment includes an inner row of piles 1 and an outer row of piles 2, which are spaced apart. Both the inner row of piles 1 and the outer row of piles 2 include multiple U-shaped steel sheet piles 11 connected in sequence. The two sides of each U-shaped steel sheet pile 11 are provided with symmetrically arranged locking buckles 12. The openings of adjacent U-shaped steel sheet piles 11 face opposite directions, and adjacent locking buckles 12 interlock to form insertion holes 13. Fixing columns 3 are inserted into the insertion holes 13. The upper parts of the multiple fixing columns 3 located in the inner row of piles 1 are connected to the upper parts of the multiple fixing columns 3 located in the outer row of piles 2 one by one via connectors 4. Compared with the prior art, the foundation pit support structure of this embodiment has significant advantages. First, the inner row of piles 1 and the outer row of piles 2 are connected in sequence by multiple U-shaped steel sheet piles 11, and the locking buckles 12 of adjacent U-shaped steel sheet piles 11 interlock to form insertion holes 13, with fixing columns 3 inserted into the insertion holes 13, ensuring a tight connection and stability of the structure. The upper parts of multiple fixed columns 3 in the inner row of piles 1 and the outer row of piles 2 are connected one by one by connectors 4, enabling the two rows of piles to work together, improving the overall structural stability, preventing soil sliding, and effectively enhancing waterproofing, especially in areas with high groundwater levels, effectively preventing leakage problems. Furthermore, all components, such as the fixed columns 3 and connectors 4, are reusable, greatly reducing engineering costs and resource waste, meeting environmental and economic requirements. This design is simple and efficient, solving common problems in existing foundation pit support technologies such as poor stability, complex construction, and non-reusability.

[0035] In this embodiment, the connector 4 includes a spring 41 and a connector 42. Both ends of the spring 41 are provided with connectors 42, which are connected to the upper part of the fixed column 3. The connection between the spring 41 and the upper part of the fixed column 3 provides an elastic connection in the support structure, enhancing the stability and adaptability of the structure. This not only improves the overall structure's resistance to deformation but also effectively alleviates stress changes caused by soil deformation or external load changes during the foundation pit support process.

[0036] In this embodiment, the connector 42 is provided with a connecting hole 43, which is fitted onto the upper part of the fixing column 3. The upper part of the fixing column 3 is provided with a fixing head 31, and the connecting hole 43 is located below the fixing head 31. By connecting the connecting hole 43 on the connector 42 and the fixing head 31, a tight connection is formed, ensuring the stable fixation between the connector 4 and the fixing column 3, improving the connection strength of the overall support structure, and further enhancing the stability and safety of the foundation pit support system.

[0037] In this embodiment, both the inner row of piles 1 and the outer row of piles 2 are provided with multiple diagonal braces 5. The multiple diagonal braces 5 are located on the inner side of the corner 14 between the inner row of piles 1 and the outer row of piles 2, and the two ends of each diagonal brace 5 are sleeved on the fixing head 31. By providing multiple diagonal braces 5 at the corner 14, the stability and bearing capacity of the structure are enhanced, forming a triangular support structure, which effectively improves the deformation resistance of the support system and ensures the long-term stability and safety of the foundation pit support.

[0038] In this embodiment, starting from the corner 14, multiple fixing heads 31 are arranged at equal intervals on both sides. Two fixing heads 31 with the same interval form a group, and the two fixing heads 31 in the same group are connected by diagonal braces 5. By reasonably arranging the fixing heads 31 and diagonal braces 5, the support force and stability at the corner are enhanced, and the overall stability and deformation resistance of the foundation pit support structure are effectively improved.

[0039] In this embodiment, multiple diagonal braces 5 are connected by connecting rods 51 to form an integral structure. This improves the overall stability and deformation resistance of the entire foundation pit support system, not only enhancing the synergistic effect between the individual diagonal braces but also effectively dispersing external loads and improving the overall load-bearing capacity and reliability of the structure.

[0040] In this embodiment, multiple walers 6 are also provided on the inner row of piles 1 and the outer row of piles 2. The walers 6 extend along the length of the inner row of piles 1 or the outer row of piles 2, and each waler 6 is connected to the fixing head 31 of multiple unconnected diagonal braces 5. By adding walers 6 to the foundation pit support structure, the stability of the structure is further enhanced, the load is reasonably distributed, and additional support force is provided, which helps to improve the deformation resistance and long-term service stability of the overall support system.

[0041] In this embodiment, the waler 6 is provided with a groove 61, which extends along the length of the waler 6 and engages with multiple fixing heads 31. The engagement of the groove 61 with the fixing heads 31 ensures a secure connection between the waler 6 and the support structure, enhancing the stability of the waler 6 and ensuring the foundation pit support system's resistance to deformation under external loads, thereby improving the overall safety and reliability of the support structure.

[0042] In this embodiment, the connectors 4 are arranged in pairs and crosswise, with multiple sets of connectors 4 distributed along the length of the inner row of piles 1 or the outer row of piles 2. By crosswise arranging the connectors 4, the stability between each row of piles and the overall resistance to deformation are increased, the stress of the support structure is effectively dispersed, and the stability and bearing capacity of the foundation pit support system under complex working conditions are improved.

[0043] In this embodiment, the insertion hole 13 is a square hole, and the fixing column 3 is a square column. This allows the fixing column 3 to be precisely inserted into the insertion hole 13, and the matching of the square structure provides a more stable connection, avoiding rotation or loosening, and ensuring the robustness and structural stability of the foundation pit support system.

[0044] The overburden layer of the site where the water purification plant's foundation pit is located mainly consists of plain fill, silt, silty soil, silty sand, silty clay, and weathered rock. Specifically, the surface layer is plain fill (yellowish-brown, slightly dense, slightly moist, 2.74m thick), underlain by silt (black, grayish-black, fluid, saturated, 0.98m thick) and silty soil (black, grayish-black, fluid, saturated, locally soft plastic, 3.33m thick). Next is silty sand (black, grayish-brown, loose, locally slightly dense, 9m thick), followed by silty clay (grayish-yellow, yellowish-brown, soft plastic, locally hard plastic, 6.62m thick) and hard plastic silty clay (yellowish-brown, hard plastic, 2.67m thick). The deeper layers consist of strongly weathered argillaceous siltstone (purplish-red, with well-developed joints and fissures, a core recovery rate of approximately 74%, and a burial depth of 21m~39.5m) and moderately weathered argillaceous siltstone (purplish-red and bluish-gray, with a silty texture, a core recovery rate of approximately 86%, and a relatively deep burial depth). Based on these geological characteristics, the foundation design uses two 15m long outer piles and one 12m long inner pile, connected by connectors 4, with a slope ratio of 1:2.

[0045] In this embodiment, a construction method for a foundation pit support structure includes the following methods:

[0046] Foundation Pit Support Structure Preparation: The foundation pit of a water purification plant has a designed depth of 5.50m and requires support. First, sheet pile machinery is used to insert inner pile 1 and outer pile 2 sequentially into the soil surrounding the foundation pit. The height of the inner pile should be lower than that of the outer pile 2 to form a slope; the specific height needs to be adjusted according to the site soil conditions. An appropriate spacing is maintained between inner pile 1 and outer pile 2 to ensure the smooth installation of subsequent connectors 4 and diagonal braces 5.

[0047] Installation of inner row of piles 1 and outer row of piles 2: First, interlock the locking buckles 12 of two adjacent U-shaped steel sheet piles 11 to form insertion holes 13. Then, insert the fixing posts 3 into the insertion holes 13, ensuring that each connection point is firm and reliable. Connect the fixing posts 3 of inner row of piles 1 and outer row of piles 2 with connectors 4. This step needs to be repeated to ensure the stability of the entire support structure.

[0048] Installation of diagonal brace 5: Next, install diagonal brace 5 to enhance the stability of the support structure. Connect one end of diagonal brace 5 to the fixing head 31 of the fixed column 3, ensuring that diagonal brace 5 is securely connected to the fixing head 31. The function of diagonal brace 5 is to provide additional support force, preventing deformation or displacement of the inner and outer piles 2 during construction, and enhancing the bearing capacity of the foundation pit support.

[0049] Installation of waler 6: After the diagonal brace 5 is installed, the waler 6 is installed. The groove 61 of the waler 6 is snapped into the upper end of the fixing head 31. The waler 6 extends along the length of the inner row of piles 1 or the outer row of piles 2, providing lateral support. The waler 6 enhances the overall stability of the support structure, prevents excessive deformation of the pit wall, and ensures the reliability of the support system.

[0050] Excavation of the foundation pit: After the installation of the foundation pit support structure is completed, the excavation work can begin. During excavation, it is important to monitor the stability of the support structure to ensure that the support system can effectively withstand the soil pressure as the foundation pit depth gradually increases, preventing collapse or deformation. The construction of the drainage system should also be carried out simultaneously to ensure that water does not accumulate in the foundation pit and affect the performance of the support system.

[0051] Retaining Structure Removal: After the foundation pit excavation is completed, the retaining structure enters the removal stage. First, remove the walers 6, then pull out the fixed columns 3, remove the connectors 4, and finally remove the inner row of piles 1 and the outer row of piles 2. Care should be taken during removal to ensure the structure disintegrates gradually and does not cause unnecessary disturbance to the surrounding soil.

Claims

1. A foundation pit support structure, comprising inner piles (1) and outer piles (2), wherein the inner piles (1) and outer piles (2) are spaced apart, and both the inner piles (1) and outer piles (2) include a plurality of U-shaped steel sheet piles (11) connected in sequence, wherein the two sides of the U-shaped steel sheet piles (11) are provided with symmetrically arranged locking buckles (12), characterized in that, The openings of two adjacent U-shaped sheet piles (11) are set in opposite directions, and two adjacent locking buckles (12) are interlocked to form a plug hole (13). A fixing column (3) is inserted into the plug hole (13). The upper part of the multiple fixing columns (3) in the inner row of piles (1) is connected to the upper part of the multiple fixing columns (3) in the outer row of piles (2) through a connector (4).

2. The foundation pit support structure according to claim 1, characterized in that, The connector (4) includes a spring (41) and a connector (42). Both ends of the spring (41) are provided with connectors (42), and the connectors (42) are connected to the upper part of the fixed column (3).

3. The foundation pit support structure according to claim 2, characterized in that, The connector (42) is provided with a connection hole (43), which is fitted onto the upper part of the fixing post (3). The upper part of the fixing post (3) is provided with a fixing head (31), and the connection hole (43) is located below the fixing head (31).

4. The foundation pit support structure according to claim 3, characterized in that, Both the inner row of piles (1) and the outer row of piles (2) are provided with multiple diagonal braces (5). The multiple diagonal braces (5) are located on the inner side of the corner (14) of the inner row of piles (1) and the outer row of piles (2). The two ends of each diagonal brace (5) are sleeved on the fixed head (31).

5. The foundation pit support structure according to claim 4, characterized in that, Starting from the corner (14), among the multiple fixed heads (31) arranged at the same interval on both sides, two fixed heads (31) with the same interval form a group, and the two fixed heads (31) in the same group are connected by diagonal bracing (5).

6. The foundation pit support structure according to claim 5, characterized in that, Multiple diagonal braces (5) are connected by connecting rods (51) to form an integral structure.

7. The foundation pit support structure according to claim 5, characterized in that, The inner row of piles (1) and the outer row of piles (2) are also provided with multiple walers (6). The walers (6) extend along the length direction of the inner row of piles (1) or the outer row of piles (2). Each waler (6) is connected to a fixed head (31) of multiple unconnected diagonal braces (5).

8. The foundation pit support structure according to claim 7, characterized in that, The waler (6) is provided with a groove (61), which extends along the length of the waler (6) and is engaged with multiple fixing heads (31).

9. The foundation pit support structure according to any one of claims 1-8, characterized in that, The connectors (4) are arranged in pairs and cross each other, and multiple sets of connectors (4) are distributed along the length direction of the inner row of piles (1) or the outer row of piles (2).

10. The foundation pit support structure according to claim 9, characterized in that, The insertion hole (13) is a square hole, and the fixing post (3) is a square post.

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