Foundation pit supporting structure and supporting method

Abstract

The invention provides a foundation pit supporting structure and method, and the structure comprises a base which is provided with a length direction and a width direction; the two first supporting plates are arranged on the two opposite sides of the base at intervals in the width direction; the two second supporting plates are arranged on the two opposite sides of the base at intervals in the length direction, and the first supporting plates and the second supporting plates are sequentially connected end to end to define a supporting cavity; wherein the first supporting plate is provided with a first reinforcing structure used for connecting the two adjacent second supporting plates, the second supporting plate is provided with a second reinforcing structure used for connecting the two adjacent first supporting plates, and the axis of the first reinforcing structure is perpendicular to the axis of the second reinforcing structure. The technical problem that in the prior art, a supporting structure is not enough in strength and prone to deformation is solved.

Description

Technical Field

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

[0002] During the excavation of a foundation pit, the original stress balance of the soil is disrupted, leading to a redistribution of stress within the soil. Under the influence of its own weight and external loads, the soil on the pit sidewalls is prone to shifting inwards, potentially causing collapses, landslides, and other safety accidents. This not only affects the construction progress and quality of the foundation pit project but also poses a serious threat to the surrounding environment and the safety of people and property. Therefore, support is necessary during foundation pit excavation. Currently, the main methods for foundation pit support are: pile support (using bored piles or sheet piles to form a retaining structure, which is costly); diaphragm walls (strong integrity but long construction period, unsuitable for small and medium-sized foundation pits); and steel support frames (assembled from horizontal steel beams and vertical columns, requiring on-site welding, lacking flexibility and unable to adapt to soil deformation). Traditional supports rely on unidirectional reinforcement, which is prone to tilting when the soil deforms unevenly. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a foundation pit support structure and support method, which solves the technical problem that insufficient strength of existing support structures easily leads to deformation.

[0004] As described in the embodiments of the present invention, the present invention employs the following technical solution:

[0005] A foundation pit support structure, comprising:

[0006] The base has both a length direction and a width direction;

[0007] Two first support plates are spaced apart along the width direction on opposite sides of the base;

[0008] Two second support plates are spaced apart along the length of the base on opposite sides, and the first support plate and the second support plate are connected end to end to form a support cavity.

[0009] The first support plate is provided with a first reinforcement structure for connecting two adjacent second support plates, and the second support plate is provided with a second reinforcement structure for connecting two adjacent first support plates, and the axis of the first reinforcement structure is perpendicular to that of the second reinforcement structure.

[0010] Preferably, the first reinforcement structure includes multiple mounting seats and multiple first reinforcement rods. The mounting seats are respectively disposed at the top corners of the first support plate and the second support plate, and the multiple first reinforcement rods are connected to the corresponding second support plates through the mounting seats.

[0011] Preferably, the second reinforcement structure consists of a plurality of second reinforcement rods inserted into the second support plate, with each end of the second reinforcement rod connected to a corresponding first support plate.

[0012] Preferably, the support structure further includes a third reinforcement structure, which includes a plurality of diagonal braces disposed on the first support plate and / or the second support plate.

[0013] Preferably, a vertical bar is provided between two adjacent diagonal bars to separate the first support plate and / or the second support plate.

[0014] Preferably, the first support plate and / or the second support plate are provided with a movable groove, and a movable plate is movably disposed in the movable groove. The movable plate is inclined in a direction away from the first support plate and / or the second support plate.

[0015] Preferably, a plurality of telescopic rods are provided between the movable plate and the movable groove, and a compression spring is provided on the outer sleeve of each telescopic rod.

[0016] Preferably, the first support plate and the second support plate are provided with a plurality of flow guide holes, and flow guide tubes are inserted into the flow guide holes.

[0017] The present invention also provides a support method, including the above-described foundation pit support structure, the support method comprising:

[0018] Step S1: According to the design dimensions of the foundation pit, locate the length and width of the base in the construction area, lay the base horizontally at the bottom of the foundation pit, and fix it with anchor bolts or counterweights.

[0019] Step S2: Install two first support plates symmetrically along the width of the base and two second support plates symmetrically along the length of the base, so that the first and second support plates are connected at their ends by bolts or welding to form a closed support cavity. The top surface of the support cavity should be 50cm-100cm higher than the ground level of the pit.

[0020] Step S3: Insert both ends of the first reinforcing rod into the mounting base at the top corner of the first support plate and connect it with the adjacent second support plate to form a transverse reinforcement; insert the second reinforcing rod through the inside of the second support plate and fix its two ends to the adjacent first support plate to form a longitudinal reinforcement; adjust the preload of the first and second reinforcing rods to ensure that their axes remain perpendicular.

[0021] Step S4: Install diagonal braces on the inner sides of the first and second support plates. The two ends of the diagonal braces are fixed to the top of the support plate and the base, respectively. Add vertical braces between adjacent diagonal braces for separation and support.

[0022] Step S5: Adjust the telescopic rod and compression spring connected to the moving plate so that the telescopic rod is at its maximum length and the compression spring is at its maximum extension length, so that the moving plate maintains an angle of 30°-60° with the first or second support plate.

[0023] Step S6: Periodically check the displacement distance of each moving plate to determine the direction of the soil pressure on the support plate;

[0024] Step S7: Based on the soil properties at the site, pour concrete into the diversion pipe.

[0025] Preferably, in step S5, the inner wall of the pit is first excavated so that the movable plate is in contact with the inner wall of the pit at an angle of 30°-60°, the telescopic rod is at its maximum telescopic length, and the compression spring is at its maximum tensile length. Then, the inner wall of the pit is backfilled to eliminate the gap between the inner wall of the pit and the movable plate.

[0026] Compared to existing technologies, this invention offers the following advantages: By arranging the first and second support plates along different directions on the base and connecting them end-to-end to form a closed support cavity, and combining this with the first reinforcement structure connecting adjacent second support plates and the second reinforcement structure connecting adjacent first support plates, with the axes of the two reinforcement structures perpendicular to each other, a bidirectional constraint structure is formed. This effectively enhances the overall rigidity and resistance to lateral earth pressure of the entire support structure, preventing deformation or overturning of the support plates under soil pressure. The first and second reinforcement structures provide support along the length and width directions respectively, and their axes are perpendicular, effectively transmitting and dispersing soil pressure from different directions, avoiding stress concentration, making the support structure more uniformly stressed, and improving the load-bearing capacity and safety of the support structure. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the support structure installation pit in one embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the support structure in one embodiment of the present invention;

[0029] Figure 3 This is a partial structural schematic diagram of the support structure in one embodiment of the present invention.

[0030] In the above attached diagram: 1. Excavation pit; 2. Base; 3. First support plate; 4. Second support plate; 5. Mounting seat; 6. First reinforcing rod; 7. Second reinforcing rod; 8. Diagonal rod; 9. Vertical rod; 10. Moving groove; 11. Moving plate; 12. Telescopic rod; 13. Compression spring; 14. Backfill soil. Detailed Implementation

[0031] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the technical solutions of this invention are further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0032] See Figures 1 to 3 The present invention provides a foundation pit support structure, comprising:

[0033] Base 2 has a length direction and a width direction;

[0034] Two first support plates 3 are spaced apart along the width direction on opposite sides of the base 2;

[0035] Two second support plates 4 are spaced apart along the length of the base 2 on opposite sides, and the first support plate 3 and the second support plate 4 are connected end to end to form a support cavity.

[0036] The first support plate 3 is provided with a first reinforcement structure for connecting two adjacent second support plates 4, and the second support plate 4 is provided with a second reinforcement structure for connecting two adjacent first support plates 3, and the axis of the first reinforcement is perpendicular to the axis of the second reinforcement structure.

[0037] In this embodiment, the base 2 has a length direction and a width direction. Two first support plates 3 are spaced apart along the width direction (left and right) of the base 2, and two second support plates 4 are spaced apart along the length direction (front and back) of the base 2. The two first support plates 3 and the two second support plates 4 are connected end to end to form a rectangular support cavity, which is used to abut against the inner wall of the soil in the foundation pit 1. In order to strengthen the strength of the support structure, a first reinforcement structure is provided on the first support plate 3. The first reinforcement structure is used to connect two adjacent second support plates 4 (i.e., two support plates in the length direction) in the two width directions respectively, enhancing the integrity in the length direction. A second reinforcement structure is provided on the second support plate 4. The second reinforcement structure is used to connect two adjacent first support plates 3 (i.e., two support plates in the width direction) in the length direction, enhancing the integrity in the width direction. The axes of the first reinforcement structure and the second reinforcement structure are perpendicular to each other, forming intersecting force directions, which can effectively transmit and disperse soil pressure from different directions, avoid stress concentration, make the structure more uniformly stressed, and improve the bearing capacity and safety of the support structure. The first reinforcement structure includes multiple mounting seats 5 and multiple first reinforcement rods 6. The mounting seats 5 are correspondingly located at the top corners of the first support plate 3 and the second support plate 4, and the multiple first reinforcement rods 6 are connected to the corresponding second support plate 4 through the mounting seats 5. Further, the second reinforcement structure consists of multiple second reinforcement rods 7 passing through the second support plate 4, with both ends of the second reinforcement rods 7 respectively connected to the corresponding first support plate 3. In this embodiment, the first reinforcement structure includes four mounting seats 5 located at the four corners of the first support plate 3 and the second support plate 4, and a first reinforcement rod 6 connected to each mounting seat 5. The first reinforcement rod 6 is connected to the second support plate 4 through two mounting seats 5 in the width direction. The two second support plates 4 transmit stress to each other through the mounting seats 5 at the corners and the first reinforcement rod 6, avoiding direct stress on the first support plate 3. The second reinforcement structure includes a second reinforcement rod 7 passing through the second support plate 4. The second support plate 4 bears the stress from the first support plate 3 on the left and transmits it to the first support plate 3 on the right through the second support plate 4 itself and the second reinforcement rod 7. At the same time, the first support plate 3 on the right can also transmit stress relative to the first support plate 3 on the left. The second support plate 4 and the second reinforcement rod 7 are equivalent to a buffer section to avoid direct stress transmission, to distribute the load, and to reduce the risk of single-point stress bearing. The first support plate 3 and the second support plate 4, which enclose a rectangular support cavity structure, can form a double quadrilateral internal and external force-bearing structure when the two first support plates 3 and the two second support plates 4 are under the same force, forming a cross force transmission path. This transforms the soil pressure from a single point of force to a uniformly distributed force, avoiding cracking or bending of the support plate caused by local stress concentration.

[0038] The support structure also includes a third reinforcement structure, which includes a plurality of diagonal bars 8 disposed on the first support plate 3 and the second support plate 4.

[0039] In this embodiment, a third reinforcing structure is provided on both first support plates 3 and both second support plates 4. The third reinforcing structure includes at least two diagonal rods 8. One end of each diagonal rod 8 is connected to the top of the first support plate 3 or the second support plate 4, and the other end is connected to the bottom of the first support plate 3 or the second support plate 4, forming a 45° angle to create a V-shaped support structure. This structure forms a triangular support system and improves the lateral deformation resistance of the first support plates 3 and the second support plates 4. A vertical rod 9 is provided between two adjacent diagonal rods 8 to separate the first support plate 3 and the second support plate 4.

[0040] In this embodiment, a vertical rod 9 is set between the two diagonal rods 8, which can divide the large-span first support plate 3 or second support plate 4 into several small areas to prevent local bulging or instability. The vertical rod 9, together with the diagonal rods 8 and the base 2, forms a portal frame or frame structure, which improves the overall bending and shear resistance of the support plate. That is, the support plate is divided into multiple force-bearing units along the height or width direction by the vertical rod 9, similar to the role of columns in curtain walls or retaining walls, which improves the out-of-plane stiffness of the panel. The vertical rod 9 is set at the midpoint between the two diagonal rods 8. The two together form a diagonal-vertical combined support system, which enhances the overall structure and stability.

[0041] Both the first support plate 3 and the second support plate 4 are provided with a moving groove 10, and a moving plate 11 is movably disposed in the moving groove 10. The moving plate 11 is inclined in a direction away from the first support plate 3 and the second support plate 4.

[0042] In this embodiment, a movable groove 10 is provided on both the first support plate 3 and the second support plate 4. A movable plate 11 is movably provided in the movable groove 10. The bottom end of the movable plate 11 is rotatably located at the bottom end of the movable groove 10, and its top end is inclined towards the soil of the foundation pit 1. By rotating the movable plate 11 in the movable groove 10, the direction of the soil's compression on the first support plate 3 or the second support plate 4 can be directly observed, which is convenient for the operators to make adaptive adjustments.

[0043] A plurality of telescopic rods 12 are provided between the movable plate 11 and the movable groove 10, and a compression spring 13 is provided on the telescopic rod 12.

[0044] In this embodiment, a reasonable number of telescopic rods 12 are set between the movable plate 11 and the movable groove 10, and compression springs 13 are fitted over the telescopic rods 12. The telescopic rods 12 and the compression springs 13 should be at their maximum extension length and maximum extension distance, so that the movable plate 11 and the first support plate 3 and the second support plate 4 are set at an angle. When the soil compresses either the first support plate 3 or the second support plate 4, the movable plate 11 can adaptably rotate towards the direction of the first support plate 3 and the second support plate 4. The operator can intuitively see the direction of soil compression and the stress on the first support plate 3 and the second support plate 4.

[0045] The first support plate 3 and the second support plate 4 are provided with multiple guide holes, and guide pipes are inserted into the guide holes. In this embodiment, guide holes are provided on the first support plate 3 and the second support plate 4, and guide pipes are inserted into the guide holes. The guide pipes extend outward into the soil. During the excavation of the foundation pit 1, groundwater will seep into the foundation pit 1, causing the support structure to bear a large water pressure, and may even cause engineering accidents such as piping and quicksand. The guide holes with guide pipes can effectively guide and drain the groundwater behind the support plate, reduce the water and soil pressure acting on the support structure, and improve the safety of the support and the stability of the foundation pit 1. At the same time, depending on the soil quality, water or mud can be actively injected into the soil to improve the soil quality, so as to reduce the compressive force of the soil on the first support plate 3 and the second support plate 4.

[0046] This embodiment also provides a support method, including the support structure of the foundation pit 1 described above. The support method includes: step S1, according to the design dimensions of the foundation pit 1, positioning the length and width directions of the base 2 in the construction area, laying the base 2 horizontally at the bottom of the foundation pit 1, and fixing it with anchor bolts or counterweights.

[0047] Step S2: Install two first support plates 3 symmetrically along the width direction of the base 2 and two second support plates 4 symmetrically along the length direction of the base 2, so that the first support plates 3 and the second support plates 4 are connected at their ends by bolts or welding to form a closed support cavity. The top surface of the support cavity should be 50cm-100cm higher than the ground height of the pit 1.

[0048] Step S3: Insert both ends of the first reinforcing rod 6 into the mounting base 5 at the top corner of the first support plate 3, and connect it with the adjacent second support plate 4 to form a transverse reinforcement; pass the second reinforcing rod 7 through the inside of the second support plate 4, and fix its two ends to the adjacent first support plate 3 to form a longitudinal reinforcement; adjust the preload of the first reinforcing rod 6 and the second reinforcing rod 7 to ensure that their axes remain perpendicular.

[0049] Step S4: Install diagonal braces 8 on the inner sides of the first support plate 3 and the second support plate 4. The two ends of the diagonal braces 8 are fixed to the top of the support plate and the base 2, respectively. Add vertical braces 9 between adjacent diagonal braces 8 for separation and support.

[0050] Step S5: Adjust the telescopic rod 12 and compression spring 13 connected to the movable plate 11 so that the telescopic rod 12 is at its maximum length and the compression spring 13 is at its maximum extension length, so that the movable plate 11 maintains an angle of 30°-60° with the first support plate 3 or the second support plate 4.

[0051] Step S6: Periodically check the displacement distance of each movable plate 11 to determine the direction of the soil pressure on the support plate;

[0052] Step S7: Based on the soil properties at the site, pour concrete into the diversion pipe.

[0053] In this embodiment, firstly, according to the design dimensions of the foundation pit 1, the length and width directions of the base 2 are located in the construction area. The base 2 is then laid horizontally at the bottom of the foundation pit 1 and fixed with anchor bolts or counterweights. Two first support plates 3 are symmetrically installed along the width direction of the base 2, and two second support plates 4 are symmetrically installed along the length direction of the base 2. All support plates are connected end to end with bolts or welding to form a complete rectangular support cavity. The height of the top surface of the support cavity is adjusted to be 50cm to 100cm higher than the ground of the foundation pit 1 to provide safety for subsequent operations. A transverse and longitudinal first reinforcing rod 6 and a second reinforcing rod 7 are installed between the support plate 3 and the second support plate 4 to enhance the overall structural stability. Diagonal rods 8 are installed on the inner sides of the first support plate 3 and the second support plate 4, and vertical rods 9 are added for separation and support to further improve the load-bearing capacity of the support structure. The telescopic rod 12 and the compression spring 13 are adjusted to set the angle between the moving plate 11 and the support plate to 30° to 60° to adapt to different soil pressures. During operation, the displacement of each moving plate 11 is checked regularly, and the direction of the soil pressure on the support plate is analyzed to ensure construction safety.

[0054] Based on the characteristics of the soil at the site, appropriate pouring operations were carried out on the diversion pipe, and drainage operations were performed inside the support cavity. In addition, when installing the movable plate 11, the inner wall of the foundation pit 1 needs to be excavated first, so that the movable plate 11 is kept at an angle of 30°-60° and fits against the inner wall of the soil. The telescopic rod 12 needs to be at its maximum telescopic length and the compression spring 13 needs to be at its maximum tensile length before backfilling the inner wall of the foundation pit 1 with soil 14 to eliminate the gap between the inner wall of the foundation pit 1 and the movable plate 11, ensuring that the soil pressure of the support structure is within a controllable range during the current installation period, and the support posture of the movable plate 11 is continuously observed.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A foundation pit support structure, characterized in that, include: The base has both a length direction and a width direction; Two first support plates are spaced apart along the width direction on opposite sides of the base; Two second support plates are spaced apart along the length of the base on opposite sides, and the first support plate and the second support plate are connected end to end to form a support cavity. The first support plate is provided with a first reinforcing structure for connecting two adjacent second support plates, and the second support plate is provided with a second reinforcing structure for connecting two adjacent first support plates, and the axis of the first reinforcing structure is perpendicular to that of the second reinforcing structure.

2. The foundation pit support structure as described in claim 1, characterized in that, The first reinforcement structure includes multiple mounting seats and multiple first reinforcement rods. The mounting seats are respectively located at the top corners of the first support plate and the second support plate, and the multiple first reinforcement rods are connected to the corresponding second support plates through the mounting seats.

3. The foundation pit support structure as described in claim 2, characterized in that, The second reinforcement structure consists of multiple second reinforcement rods inserted into the second support plate, with each end of the second reinforcement rod connected to a corresponding first support plate.

4. A foundation pit support structure as described in any one of claims 1-3, characterized in that, The support structure further includes a third reinforcement structure, which includes a plurality of diagonal braces disposed on the first support plate and / or the second support plate.

5. The foundation pit support structure as described in claim 4, characterized in that, A vertical bar is provided between two adjacent diagonal bars to separate the first support plate and / or the second support plate.

6. The foundation pit support structure as described in claim 1, characterized in that, The first support plate and / or the second support plate are each provided with a movable groove, and a movable plate is movably disposed in the movable groove. The movable plate is inclined in a direction away from the first support plate and / or the second support plate.

7. The foundation pit support structure as described in claim 6, characterized in that, Multiple telescopic rods are provided between the movable plate and the movable groove, and each telescopic rod is fitted with a compression spring.

8. The foundation pit support structure as described in claim 1, characterized in that, The first support plate and the second support plate are provided with multiple flow guide holes, and flow guide tubes are inserted into the flow guide holes.

9. A support method, characterized in that, Including the foundation pit support structure as described in any one of claims 1-8, the support method includes: Step S1: According to the design dimensions of the foundation pit, locate the base in the length and width directions in the construction area, lay the base horizontally at the bottom of the foundation pit, and fix it with anchor bolts or counterweights. Step S2: Install two first support plates symmetrically along the width of the base and two second support plates symmetrically along the length of the base, so that the first and second support plates are connected at their ends by bolts or welding to form a closed support cavity. The top surface of the support cavity should be 50cm-100cm higher than the ground level of the pit. Step S3: Insert both ends of the first reinforcing rod into the mounting base at the top corner of the first support plate and connect it with the adjacent second support plate to form a transverse reinforcement; insert the second reinforcing rod through the inside of the second support plate and fix its two ends to the adjacent first support plate to form a longitudinal reinforcement; adjust the preload of the first and second reinforcing rods to ensure that their axes remain perpendicular. Step S4: Install diagonal braces on the inner sides of the first and second support plates. The two ends of the diagonal braces are fixed to the top of the support plate and the base, respectively. Add vertical braces between adjacent diagonal braces for separation and support. Step S5: Adjust the telescopic rod and compression spring connected to the moving plate so that the telescopic rod is at its maximum length and the compression spring is at its maximum extension length, so that the moving plate maintains an angle of 30°-60° with the first or second support plate. Step S6: Periodically check the displacement distance of each moving plate to determine the direction of the soil pressure on the support plate; Step S7: Based on the soil properties at the site, pour concrete into the diversion pipe.

10. The support method as described in claim 9, characterized in that, In step S5, the inner wall of the pit is first excavated to keep the moving plate at an angle of 30°-60°, with the telescopic rod at its maximum telescopic length and the compression spring at its maximum tensile length. Then, the inner wall of the pit is backfilled to eliminate the gap between the inner wall of the pit and the moving plate.

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