A support device and construction method for deep foundation pit slopes

Abstract

This application relates to a support device and construction method for deep foundation pit slopes, belonging to the field of foundation pit support. It includes a spiral support steel layer, which comprises multiple sections of retaining steel. These retaining steel sections are inclined and connected sequentially to form a spiral shape. The inclination angle of the retaining steel is α, the height of the foundation pit is h, and the perimeter of the foundation pit is c. The formula for calculating the inclination angle / height and perimeter is as follows: tanα>h / 3c. A fixing component connects the retaining steel to the slope. Because the spiral support steel layer forms a unified whole, if an external force is applied to any point on the spiral support steel layer by the slope, the entire spiral support steel layer can resist the applied force, making the protection of the entire slope a unified whole, and making it difficult for external forces to damage the slope.

Description

Technical Field

[0001] This application relates to the field of foundation pit support, and in particular to a support device and construction method for deep foundation pit slopes. Background Technology

[0002] Excavation pit support refers to the measures taken to support, reinforce, and protect the sidewalls and surrounding environment of an excavation pit to ensure the safety of underground structure construction and the surrounding environment. The portion of the excavation pit near the ground surface is usually a sloping slope. To prevent the excavation pit from collapsing, slope protection devices must be installed on the sloping slope to ensure its stability.

[0003] In related technologies, Chinese patent application CN202222522263.1 discloses a retaining wall for geotechnical foundation pit support, including a base plate and a protective plate hinged to one side of the base plate. A limiting frame is symmetrically installed on one side of the protective plate, and an upper and lower crossbeam are slidably connected between the two limiting frames. A bidirectional threaded rod is threaded through the upper and lower crossbeams. A diagonal brace is symmetrically hinged between the upper crossbeam and the base plate. A support frame is fixedly connected to the lower crossbeam, and the diagonal brace passes through the support frame, with one side of the diagonal brace fitting against the inner wall of the support frame. In use, rotating the bidirectional threaded rod causes the upper and lower crossbeams to move relative to each other. When the upper crossbeam descends, the lower crossbeam rises, changing the inclination angle of the diagonal brace, thereby adjusting the inclination of the protective plate to fit the sloping inner wall of the foundation pit.

[0004] In conclusion, the inventors believe that although the above-mentioned foundation pit support retaining wall can be adjusted in angle, the support method is too simple, relying only on the limiting frame, upper beam, lower beam and diagonal bracing plate to support the area around the foundation pit. Furthermore, the stress of the foundation pit support retaining wall is ultimately borne by the diagonal bracing plate, resulting in low support strength for deep foundations and high construction risk. Summary of the Invention

[0005] In order to provide a slope protection device with high support strength for deep foundations, this application provides a slope protection device and construction method for deep foundation pits.

[0006] This application provides a support device and construction method for deep foundation pit slopes, which adopts the following technical solution:

[0007] In the first aspect, this application provides a solution A, which adopts the following technical solution:

[0008] A support device for deep foundation pit slopes includes a spiral support steel layer, which comprises multiple sections of retaining steel. The retaining steel is inclined and the multiple sections of retaining steel are connected in sequence to form a spiral. The inclination angle of the retaining steel is α, the height of the foundation pit is h, and the perimeter of the foundation pit is c. The calculation formulas for the inclination angle, height, and perimeter are as follows: tanα>h / 3c.

[0009] The retaining steel is connected to the slope by a fixing component.

[0010] By adopting the above technical solution, the spiral support steel layer, being a spiral shape composed of multiple sections of enclosing steel connected sequentially, forms a unified whole around the slope. Therefore, if an external force is applied to any point on the spiral support steel layer, the entire spiral support steel layer can resist the applied force, providing integrated protection for the entire slope; external forces are unlikely to damage the slope. The spiral support steel layer configuration, satisfying tanα > h / 3c, ensures that any side of the enclosing steel has at least three layers of enclosing steel for slope protection, guaranteeing the protective effect of the spiral support steel layer on the slope.

[0011] Optionally, the fixing component includes a fixing sleeve and a steel bar bundle, the steel bar bundle passing through the fixing sleeve and the surrounding steel and inserted into the slope, the fixing sleeve being fixedly connected to the surrounding steel.

[0012] By adopting the above technical solution and setting the fixing components, the steel bar bundles can connect the retaining steel to the slope. Since the steel bar bundles are inserted into the slope, the connection between the steel bar bundles and the slope is relatively tight. The steel bar bundles are then fixed to the retaining steel through fixing sleeves, so that the retaining steel and the slope form a tight connection. The spiral support steel layer has a good support effect on the slope.

[0013] Optionally, a support assembly is provided between the two sections of retaining steel, and the support assembly is connected to the retaining steel located above the support assembly and the retaining steel located below the support assembly.

[0014] By adopting the above technical solution, since there are more steel segments on the spiral support steel layer, the stability of the spiral support steel layer is lower than that of the integrally formed spiral support steel layer. Therefore, the setting of the support components allows the support components to connect the upper, middle and lower sections of the surrounding steel on the same slope into one, so the stability of the entire spiral support steel layer is higher and the support effect on the slope is better.

[0015] Optionally, the support assembly includes an upper support plate, a lower support plate, and a support rod. The upper support plate is fixedly connected to one end of the support rod, and the lower support plate is fixedly connected to the other end of the support rod. The upper support plate is fixedly connected to a retaining steel structure located above the upper support plate, and the lower support plate is fixedly connected to a retaining steel structure located below the lower support plate.

[0016] By adopting the above technical solution, the upper support plate fixes the support rod to the retaining steel, and the lower support plate fixes the support rod to the retaining steel. In this simple structure, the height of the spiral support steel layer is fixed. If a certain position of the slope is subjected to force, causing the steel reinforcement bundle to be stressed, the steel reinforcement bundle will transfer the force to the connected retaining steel. The retaining steel will then transfer the force to other retaining steel and support rods, so that the entire spiral support layer and support components will generate forces against the slope, making it difficult for the slope to deform or collapse.

[0017] Optionally, a metal mesh layer is provided between the spiral support steel layer and the slope. The metal mesh layer includes a metal mesh and insert nails. The metal mesh is laid on the slope. One end of the insert nail is fixedly connected to the metal mesh, and the other end is inserted into the slope.

[0018] By adopting the above technical solution, the metal mesh in the metal mesh layer has a dense mesh structure, which can intercept small soil particles on the slope and play the role of the first layer of base protection; the design of inserting nails can make the metal mesh fit tightly with the slope, so that the metal mesh can intercept soil particles on the slope more effectively, thus making the base protection of the slope more effective.

[0019] Optionally, a concrete layer is provided between the metal mesh and the spiral support steel layer.

[0020] By adopting the above technical solution, the concrete layer further integrates the metal mesh with the slope, and before the concrete hardens, it can flow into the gaps where the insert nails are inserted into the slope, making the connection between the metal mesh and the slope more stable and providing better protection for the slope.

[0021] Optionally, a connecting plate is provided between two adjacent sections of the retaining steel on adjacent slope surfaces.

[0022] By adopting the above technical solution, since the planar structure of the foundation pit is rectangular, the adjacent retaining steel on the adjacent slopes cannot form an effective and stable connection. Therefore, the setting of the connecting plate can form a stable triangular structure with the adjacent retaining steel on the adjacent slopes, so that the retaining steel on different slopes can form a stable spiral support steel layer.

[0023] Secondly, this application provides a construction method for a support device for deep foundation pit slopes, employing the following technical solution:

[0024] A construction method for the above-mentioned deep foundation pit slope support device includes the following steps:

[0025] Step 1: Lay the metal mesh on the slope and insert the nails into the slope.

[0026] Step 2: Spray concrete onto the metal mesh and slope to form a concrete layer;

[0027] Step 3: Fix the retaining steel to the slope using fixing components. The retaining steel is fixed at an angle, and multiple sections of retaining steel are fixed and connected in sequence.

[0028] Step 4: Fix the steel connecting plates on the adjacent sections of the adjacent slope to form a triangular support structure.

[0029] Step 5: Connect the two adjacent steel support components.

[0030] By adopting the above technical solution, in step 1, the metal mesh is first laid on the slope to form a base protection for the slope; in step 2, concrete is sprayed on the slope to further fix the metal mesh to the slope, so that the metal mesh and concrete work together to protect the slope; in steps 3 and 4, multiple sections of retaining steel are connected to the slope using fixing components, and the multiple sections of retaining steel are connected sequentially. Adjacent sections of retaining steel on adjacent slope surfaces are fixedly connected using connecting plates; thus, the entire spiral support steel layer forms a spiral shape on the slope, making the entire spiral support steel layer a whole, and the support for the slope also forms a whole; in step 5, by setting up support components, the spiral support steel layer is further fixed vertically, making the stability of the spiral support steel layer higher.

[0031] In summary, this application includes at least one of the following beneficial technical effects:

[0032] 1. In this application, the spiral support steel layers around the slope form a whole. Therefore, as long as an external force is applied to a point on the spiral support steel layer by the slope, the entire spiral support steel layer can resist the applied external force, and the protection of the entire slope becomes a whole. It is difficult for external forces to damage the slope. The spiral support steel layer setting that satisfies tanα>h / 3c can ensure that any side of the surrounding steel has at least three layers of surrounding steel for slope protection, thus ensuring the protective effect of the spiral support steel layer on the slope.

[0033] 2. The setting of the support components allows the upper, middle and lower sections of the surrounding steel on the same slope to be connected into one, which makes the stability of the entire spiral support steel layer higher and the support effect on the slope better.

[0034] 3. The connection plate can form a stable triangular structure with the adjacent retaining steel on the adjacent slope surface, so that the retaining steel on different slope surfaces can form a stable spiral support steel layer. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the external structure of an embodiment of this application;

[0036] Figure 2This is a schematic diagram of the cross-sectional structure intended to show an embodiment of this application;

[0037] Figure 3 This is a schematic diagram intended to show the exploded structure of the metal mesh layer and the concrete layer;

[0038] Figure 4 This is a structural schematic diagram intended to show the spiral support steel layer and connecting plate;

[0039] Figure 5 It is intended to show Figure 1 Enlarged structural diagram of the fixed component and support component at point A.

[0040] Explanation of reference numerals in the attached drawings: 1. Slope; 2. Metal mesh layer; 21. Metal mesh; 22. Inserted nail; 3. Concrete layer; 4. Spiral support steel layer; 41. Enclosure steel; 5. Fixing component; 51. Fixing sleeve; 511. Fixing seat; 512. Enclosing ring; 52. Reinforcing bar bundle; 6. Connecting plate; 7. Support component; 71. Upper support plate; 72. Lower support plate; 73. Support rod. Detailed Implementation

[0041] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0042] This application discloses a support device for deep foundation pit slopes. (Refer to...) Figure 1 and Figure 2 A support device for a deep foundation pit slope 1 includes a metal mesh layer 2, a concrete layer 3, and a spiral support steel layer 4. The metal mesh layer 2 is connected to the slope 1. Part of the concrete layer 3 is located on the side of the metal mesh layer 2 away from the slope 1, and part of the concrete layer 3 covers the metal mesh layer 2. The spiral support steel layer 4 is located on the side of the concrete layer 3 away from the slope 1. A fixing component 5, a connecting plate 6, and a support component 7 are connected to the spiral support steel layer 4.

[0043] Reference Figure 3 The metal mesh layer 2 includes a metal mesh 21 and insert nails 22. The metal mesh 21 is a fine wire mesh and is laid on the slope 1. The insert nails 22 are arranged in multiples and are evenly welded and fixed to the side of the metal mesh 21 near the slope and inserted into the slope 1.

[0044] Reference Figure 3 The concrete layer 3 is formed by spraying concrete onto the metal mesh 21 and the slope 1 and solidifying it; part of the concrete layer 3 is located on the side of the metal mesh away from the slope 1, and part of the concrete layer 3 covers the metal mesh and is bonded to the slope 1.

[0045] Reference Figure 1 and Figure 4The spiral support steel layer 4 includes multiple sections of retaining steel 41. The retaining steel 41 can be U-shaped steel, H-shaped steel, or ordinary rectangular steel. The multiple sections of retaining steel 41 are connected in sequence by bolts, and the retaining steel 41 is inclined with an inclination angle of α. The height of the foundation pit is h, and the perimeter of the foundation pit is c. The calculation formulas for the inclination angle, height, and perimeter are as follows: tanα>h / 3c. The multiple sections of inclined retaining steel 41 are used to form a spiral on the slope 1. In this embodiment, U-shaped steel is used. The inclination angle of the retaining steel 41 in this embodiment is 0.3°, the height of the foundation pit is 12m, and the perimeter of the foundation pit is 600m.

[0046] Reference Figure 5 Multiple fixing components 5 are provided, and the multiple fixing components 5 are evenly distributed on the surrounding steel 41. The fixing component 5 includes a fixing sleeve 51 and a steel bar bundle 52. The fixing sleeve 51 is integrally connected by a fixing seat 511 and a surrounding ring 512. The fixing seat 511 is annular, and the surrounding ring 512 is annular. The inner diameter of the surrounding ring 512 is equal to the inner diameter of the fixing seat 511, and the outer diameter of the surrounding ring 512 is smaller than the outer diameter of the fixing seat 511. The steel bar bundle 52 passes through the surrounding ring 512, the fixing seat 511, the surrounding steel 41, the concrete layer 3 and the metal mesh 21 in sequence, and is inserted into the slope 1.

[0047] Reference Figure 1 Multiple connecting plates 6 are provided. The connecting plates 6 are strip-shaped steel plates. The connecting plates 6 are welded and fixed to the two adjacent sections of the surrounding steel 41 on the adjacent slope 1. The connecting plates 6 and the two sections of surrounding steel 41 together form a triangle.

[0048] Reference Figure 5 Multiple support components 7 are provided, and the multiple support components 7 are evenly distributed between two adjacent upper and lower enclosing steel sections 41. The support components 7 include an upper support plate 71, a lower support plate 72, and a support rod 73. The upper support plate 71 is rectangular and is fixedly connected to the upper enclosing steel 41 of the adjacent enclosing steel 41 by bolts. The lower support plate 72 is fixedly connected to the lower enclosing steel 41 of the adjacent enclosing steel 41 by bolts. The support rod 73 is strip-shaped, with one end integrally formed with the upper support plate 71 and the other end integrally formed with the lower support plate 72.

[0049] A construction method for a support device for deep foundation pit slopes includes the following steps:

[0050] Step 1: Lay the metal mesh 21 on the slope 1 and insert the insert nails 22 into the slope 1;

[0051] Step 2: Spray concrete onto the metal mesh 21 and the slope 1 until the concrete covers the entire metal mesh 21. After 24 hours, a concrete layer 3 will be formed.

[0052] Step 3: Tilt the retaining steel 41 at 0.3° and weld the fixing sleeve 51 to the retaining steel 41. Pass the reinforcing bar bundle 52 through the fixing sleeve 51, the retaining steel 41 and the concrete layer 3 in sequence, and insert it into the slope 1. Finally, fix the retaining steel 41 on the slope 1. Fix the adjacent retaining steel 41 to the slope 1 in the same way. Then weld the adjacent retaining steel 41 in place.

[0053] Step 4: Weld and fix the two adjacent sections of steel 41 on the adjacent slope 1 with connecting plates 6 to form a triangular support structure.

[0054] Step 5: Connect the two adjacent sections of retaining steel 41 with the support assembly 7. Specifically, the upper support plate 71 is fixedly connected to the bottom of the upper retaining steel 41 with bolts; the lower support plate 72 is fixedly connected to the top of the lower retaining steel 41 with bolts; finally, the spiral support steel layer 4 is stably connected to the slope 1.

[0055] The implementation principle of a support device for deep foundation pit slopes is as follows: Step 1, a metal mesh 21 is laid on the slope 1, and inserting nails 22 into the slope 1 to form primary protection for the slope 1; Step 2, concrete is sprayed onto the metal mesh 21 and the slope 1 until the concrete covers the entire metal mesh 21. After 24 hours, a concrete layer 3 is formed. The concrete layer 3 firmly connects the metal mesh 21 to the slope 1, and a small amount of concrete sprayed into the inserting nails 22 further strengthens the connection between the slope 1 and the metal mesh 21; Step 3, the retaining steel 41 is tilted at 0.3°, and the fixing sleeve 51 is welded to the retaining steel 41. The reinforcing bar bundle 52 is passed through the fixing sleeve 51, the retaining steel 41, and the concrete layer 3 in sequence, and inserted into the slope 1. Finally, the retaining steel 41 is fixed. On slope 1, adjacent retaining steel sections 41 are fixed to slope 1 in the same manner. Then, adjacent retaining steel sections 41 are welded together to form a spiral support steel layer 4. The spiral support steel layer 4 integrates the support force of the entire slope 1 into one, resulting in good support effect. In step 4, adjacent sections of retaining steel sections 41 on adjacent slope 1 are welded together with connecting plates 6 to form a triangular support structure, which makes the spiral support steel layer 4 more stable. In step 5, adjacent sections of retaining steel sections 41 are connected with support components 7. Specifically, the upper support plate 71 is bolted to the bottom of the upper retaining steel section 41, and the lower support plate 72 is bolted to the top of the lower retaining steel section 41. Finally, the spiral support steel layer 4 is stably connected to the slope 1.

[0056] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A support device for deep foundation pit slopes, characterized in that: The structure includes a spiral support steel layer (4), which comprises multiple sections of retaining steel (41). The retaining steel (41) is inclined and the multiple sections of retaining steel (41) are connected in sequence to form a spiral. The inclination angle of the retaining steel (41) is α, the height of the pit is h, and the perimeter of the pit is c. The calculation formulas for the inclination angle, height, and perimeter are as follows: tanα>h / 3c. The retaining steel (41) is connected to the slope (1) by a fixing component (5). The fixing component (5) includes a fixing sleeve (51) and a steel bar bundle (52). The steel bar bundle (52) passes through the fixing sleeve (51) and the surrounding steel (41) and is inserted into the slope (1). The fixing sleeve (51) and the surrounding steel (41) are fixedly connected. A support assembly (7) is provided between the upper and lower sections of the retaining steel (41), and the support assembly (7) is connected to the retaining steel (41) located above the support assembly (7) and the retaining steel (41) located below the support assembly (7); A connecting plate (6) is connected between two adjacent sections of the surrounding steel (41) on the adjacent slope (1) surface.

2. The support device for deep foundation pit slopes according to claim 1, characterized in that: The support assembly (7) includes an upper support plate (71), a lower support plate (72), and a support rod (73). The upper support plate (71) is fixedly connected to one end of the support rod (73), and the lower support plate (72) is fixedly connected to the other end of the support rod (73). The upper support plate (71) is fixedly connected to the retaining steel (41) located above the upper support plate (71), and the lower support plate (72) is fixedly connected to the retaining steel (41) located below the lower support plate (72).

3. The support device for deep foundation pit slopes according to claim 1, characterized in that: A metal mesh layer (2) is provided between the spiral support steel layer (4) and the slope (1). The metal mesh layer (2) includes a metal mesh (21) and an insert nail (22). The metal mesh (21) is laid on the slope (1). One end of the insert nail (22) is fixedly connected to the metal mesh (21), and the other end is inserted into the slope (1).

4. The support device for deep foundation pit slopes according to claim 3, characterized in that: A concrete layer (3) is provided between the metal mesh (21) and the spiral support steel layer (4).

5. A construction method for a deep foundation pit slope support device as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Lay the metal mesh (21) on the slope (1) and insert the nails (22) into the slope (1); Step 2: Spray concrete onto the metal mesh (21) and the slope (1) to form a concrete layer (3); Step 3: Fix the retaining steel (41) to the slope (1) using the fixing components (5), fix the retaining steel (41) at an angle, and fix multiple retaining steel (41) sections in sequence; Step 4: Fix two adjacent retaining steel (41) sections on adjacent slope (1) surfaces with connecting plates (6) to form a triangular support structure; Step 5: Connect two adjacent retaining steel (41) sections above and below with support components (7).

Images