A deep foundation spiral pile support system

Abstract

The application relates to the technical field of foundation pit supporting, in particular to a deep foundation pit screw pile supporting system, which comprises a screw pile, two parallel arranged pipe fittings are fixedly connected in the screw pile, a feeding screw rod is inserted in the pipe fitting, a taper head is fixedly connected to one end of the feeding screw rod, an extension shaft is fixedly connected to the other end of the feeding screw rod, a pile cap is sleeved on the end of the screw pile, a through hole is arranged in the end of the screw pile and penetrates the screw pile in the radial direction, the pile cap is fixed in the through hole through first bolts, and a connecting structure is arranged in the pile cap to connect a slope protection plate. The application is aimed at the seasonal frozen soil environment, a pair of rotatable feeding screw rods are arranged in the screw pile to prevent the screw pile from being damaged due to soil freezing and deformation, the service life and the reusable times of the screw pile are prolonged, and the construction cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support technology, and in particular to a deep foundation pit spiral pile support system. Background Technology

[0002] To ensure the safety of underground structure construction and the surrounding environment of the foundation pit, temporary support is required for the inner wall of the foundation pit during construction.

[0003] like Figure 1 As shown in the figure, this is a temporary support structure for a foundation pit in the prior art. The external slope protection plate is temporarily anchored to the inner wall of the foundation pit using helical piles. Due to the detachable nature of the helical piles, they can be disassembled and reused after construction to reduce construction costs.

[0004] However, in seasonally frozen soil regions, as temperatures drop, the soil expands in volume due to freezing. The expansion of the soil between the pitches of the helical blades on the outer wall of the helical pile causes the helical blades to deform and be damaged along the axial direction. The expansion of the soil volume also applies radial force to the helical pile body, causing the helical pile body to deform and be damaged, resulting in a significant reduction in the service life and reusability of the helical pile. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies where spiral piles deform and are damaged due to soil freezing, and to propose a deep foundation pit spiral pile support system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] Design a deep foundation pit helical pile support system, including a helical pile, two parallel pipes fixedly connected inside the helical pile, a feeding screw inserted inside the pipe, a conical head fixedly connected to one end of the feeding screw, and an extension shaft fixedly connected to the other end of the feeding screw, a pile cap sleeved at the end of the helical pile, a through hole radially extending through the end of the helical pile, the pile cap being fixed in the through hole by a first bolt, and a connecting structure provided inside the pile cap for connecting the slope protection plate.

[0008] Preferably, the spiral pile has a partition structure to divide the spiral pile into a receiving cavity. The partition structure includes a connecting block and a separating block. The shape of the connecting block matches the spiral pile and the connecting block is fixed to the end of the pipe. The separating block is slidably fitted inside the spiral pile. The separating block has a radially penetrating opening for accommodating the passage of the first bolt.

[0009] Preferably, the isolation block has a sliding hole inside, the end of the extension shaft is slidably fitted in the sliding hole and fixedly connected to a frustum-shaped insert, and a compression spring is provided in the sliding hole to apply elastic force to the insert.

[0010] Preferably, the connection structure includes a heat-conducting plate, a second bolt fixed to one side of the heat-conducting plate, an installation hole through which the slope protection plate is formed, the second bolt being connected to the installation hole, and a heat-conducting column fixed to the other side of the heat-conducting plate, the heat-conducting column being fixedly connected to the pile cap and extending into the helical pile.

[0011] Preferably, the spiral post is provided with a driving structure to drive the insertion block to rotate. The driving structure includes a front panel, a rear panel, and a short shaft. The front panel and the rear panel are slidably fitted inside the spiral post. One end of the short shaft is rotatably connected to the front panel, and the other end of the short shaft is rotatably connected to the rear panel. An arc-shaped guide groove is provided through the front panel, and a guide block is slidably fitted in the guide groove. A ring gear is rotatably mounted on the surface of the rear panel, and the guide block is fixedly connected to the end face of the ring gear. A memory metal wire is provided in the guide groove to drive the guide block to move.

[0012] Preferably, a driven gear is connected to the middle of the outer wall of the short shaft via a one-way bearing, and the driven gear is matched with the ring gear.

[0013] Preferably, one end of the short shaft passes through the rear panel and has a frustum-shaped slot on the end face, and the insert block cooperates with the slot.

[0014] The present invention proposes a deep foundation pit helical pile support system, which has the following advantages: the deep foundation pit helical pile support system is designed for seasonal frozen soil environments, and a pair of rotatable feeding screws are installed inside the helical pile to prevent the helical pile from deforming and being damaged due to soil freezing, thereby extending the service life of the helical pile and the number of times it can be reused. Attached Figure Description

[0015] Figure 1 This is a temporary support structure for foundation pits in the existing technology.

[0016] Figure 2 This is a schematic diagram of the structure of a deep foundation pit spiral pile support system proposed in this invention. Figure 1 .

[0017] Figure 3 This is a schematic diagram of the structure of a deep foundation pit spiral pile support system proposed in this invention. Figure 2 .

[0018] Figure 4 This is a schematic diagram of the slope protection plate of a deep foundation pit spiral pile support system proposed in this invention.

[0019] Figure 5 This is a schematic diagram of the external structure of the spiral pile of a deep foundation pit spiral pile support system proposed in this invention.

[0020] Figure 6This is a schematic diagram of the internal structure of the spiral pile in a deep foundation pit spiral pile support system proposed in this invention. Figure 1 .

[0021] Figure 7 This is a schematic diagram of the internal structure of the spiral pile in a deep foundation pit spiral pile support system proposed in this invention. Figure 2 .

[0022] Figure 8 This invention proposes a deep foundation pit spiral pile support system. Figure 5 Front view of the central heat-conducting plate.

[0023] Figure 9 This invention proposes a deep foundation pit spiral pile support system. Figure 8 Cross-sectional view along the BB direction.

[0024] Figure 10 This invention proposes a deep foundation pit spiral pile support system. Figure 9 Enlarged view of point A in the middle.

[0025] Figure 11 This invention proposes a deep foundation pit spiral pile support system. Figure 8 Cross-sectional view along the CC direction.

[0026] Figure 12 This is a schematic diagram of the driving structure of a deep foundation pit spiral pile support system proposed in this invention.

[0027] Figure 13 This is an exploded view of the driving structure of a deep foundation pit spiral pile support system proposed in this invention.

[0028] Figure 14 This is a schematic diagram of the driven gear in a deep foundation pit spiral pile support system proposed in this invention.

[0029] In the diagram: 1. Slope protection plate; 101. Mounting hole; 2. Heat-conducting plate; 201. Second bolt; 3. Heat-conducting column; 4. Pile cap; 5. Helical pile; 501. Through hole; 6. Connecting block; 7. Pipe fitting; 8. Feeding screw; 9. Conical head; 10. Isolation block; 11. First bolt; 12. Extension shaft; 13. Sliding hole; 14. Compression spring; 15. Insert block; 16. Rear panel; 17. Ring gear; 18. Front panel; 19. Driven gear; 20. Short shaft; 21. Slot; 22. Guide block; 23. Guide groove; 24. Memory metal wire; 25. Opening; 26. One-way bearing. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] Reference Figures 2-7 A deep foundation pit spiral pile support system includes a spiral pile 5, two parallel pipe fittings 7 are fixedly connected inside the spiral pile 5, a feeding screw 8 is inserted into the pipe fitting 7, a cone head 9 is fixedly connected to one end of the feeding screw 8, and an extension shaft 12 is fixedly connected to the other end of the feeding screw 8. A pile cap 4 is provided at the end of the spiral pile 5, and a through hole 501 is radially opened at the end of the spiral pile 5. The pile cap 4 is fixed in the through hole 501 by a first bolt 11. A connecting structure is provided inside the pile cap 4 to connect the slope protection plate 1.

[0032] When supporting the inner wall of the foundation pit, this device uses a power hydraulic equipment to drive the helical piles 5 into the inner wall of the foundation pit. In front of the slope protection plate 1, depending on the soil quality of the foundation pit, it is selected whether to install the feeding screw 8.

[0033] If the soil in the foundation pit does not freeze, the pile cap 4 can be directly connected to the helical pile 5 by the first bolt 11, and the slope protection plate 1 can be connected to the pile cap 4 by the connecting structure.

[0034] If the soil in the foundation pit will freeze in low temperatures, the feeding screw 8 needs to be inserted into the pipe fitting 7, and the cone 9 at the end of the feeding screw 8 should be inserted into the soil through the pipe fitting 7. Then, the extension shaft 12 is driven to rotate. The rotation of the extension shaft 12 drives the feeding screw 8 to rotate. During the rotation of the feeding screw 8, the soil near the helical blades on the helical pile 5 will be transported into the helical pile 5.

[0035] After the soil near the helical blades is transported to the helical pile 5, the soil around the helical blades becomes loose. When the soil freezes and causes volume expansion, the loose soil structure around the helical blades leaves enough space for expansion to prevent the helical blades from being deformed or damaged due to the expansion of the soil between the pitches of the helical blades along the axial direction of the helical pile 5.

[0036] In addition, as the feeding screw 8 transports soil into the interior of the helical pile 5, the interior of the helical pile 5 will also be filled with soil. When the soil outside the helical pile 5 freezes, the frozen soil outside will exert a radial force on the helical pile 5 from the outside. Meanwhile, the soil inside the helical pile 5 will also freeze and expand under the action of low temperature, exerting a radial force on the helical pile 5 from the inside, so as to balance the forces inside and outside the helical pile 5 and thus prevent the helical pile 5 from deforming.

[0037] like Figure 6 and Figure 7As shown, the spiral pile 5 is provided with a partition structure to divide the spiral pile 5 into a receiving cavity. The partition structure includes a connecting block 6 and an isolation block 10. The shape of the connecting block 6 matches the spiral pile 5 and the connecting block 6 is fixed to the end of the pipe fitting 7. The isolation block 10 is slidably fitted inside the spiral pile 5. An opening 25 is provided on the isolation block 10 through the radial direction to accommodate the passage of the first bolt 11.

[0038] After the spiral pile 5 is installed, the isolation block 10 can be slidably inserted into the spiral pile 5. After aligning the opening 25 with the through hole 501, the first bolt 11 can be inserted to fix the isolation block 10.

[0039] Inside the spiral pile 5, under the division of the isolation block 10, a receiving cavity is formed between the isolation block 10 and the spiral blade to hold the soil. The soil delivered to the spiral pile 5 by the feeding screw 8 will fill the receiving cavity.

[0040] like Figures 9-11 As shown, the isolation block 10 has a sliding hole 13 inside, the end of the extension shaft 12 is slidably fitted in the sliding hole 13 and fixed with a frustum-shaped insert 15, and a compression spring 14 is provided in the sliding hole 13 to apply elastic force to the insert 15.

[0041] The insert 15 is subjected to the elastic force of the compression spring 14. Under the action of the elastic force, the insert 15 can extend out from the end opening of the helical pile 5, so that the construction personnel can easily remove the feeding screw 8 from the pipe 7 when disassembling the helical pile 5 later.

[0042] like Figure 4 and Figures 9-11 As shown, the connection structure includes a heat-conducting plate 2, a second bolt 201 fixedly connected to one side of the heat-conducting plate 2, an installation hole 101 through which the slope protection plate 1 is opened, the second bolt 201 is connected to the installation hole 101, and a heat-conducting column 3 is fixedly connected to the other side of the heat-conducting plate 2. The heat-conducting column 3 is fixedly connected to the pile cap 4 and extends into the helical pile 5.

[0043] During the day, when there is plenty of sunlight, the surface of the slope protection board 1 is coated with black to absorb solar energy and heat itself up. After the slope protection board 1 heats up, it can transfer heat to the interior of the spiral pile 5 through the heat-conducting plate 2 and the heat-conducting column 3, so that the internal space of the spiral pile 5 between the isolation block 10 and the pile cap 4 is heated.

[0044] As the ambient temperature drops at night, the excellent heat dissipation effect of the heat-conducting plate 2 and the heat-conducting column 3 can cool down the internal space of the spiral pile 5.

[0045] like Figure 9-14As shown, the spiral pile 5 is equipped with a drive structure to drive the insertion block 15 to rotate. The drive structure includes a front panel 18, a rear panel 16, and a short shaft 20. The front panel 18 and the rear panel 16 are slidably fitted inside the spiral pile 5. One end of the short shaft 20 is rotatably connected to the front panel 18, and the other end of the short shaft 20 is rotatably connected to the rear panel 16. An arc-shaped guide groove 23 is provided through the front panel 18. A guide block 22 is slidably fitted in the guide groove 23. A ring gear 17 is rotatably mounted on the surface of the rear panel 16. The guide block 22 is fixedly connected to the end face of the ring gear 17. A memory metal wire 24 is provided in the guide groove 23 to drive the guide block 22 to move. A driven gear 19 is connected to the middle of the outer wall of the short shaft 20 through a one-way bearing 26. The driven gear 19 matches the ring gear 17. One end of the short shaft 20 passes through the rear panel 16 and has a frustum-shaped slot 21 on its end face. The insertion block 15 is fitted into the slot 21.

[0046] Under temperature changes, the spiral-shaped memory metal wire 24 drives the guide block 22 to slide back and forth within the guide groove 23. During this back-and-forth movement, the guide block 22 drives the ring gear 17 to rotate in both the forward and reverse directions.

[0047] When the ring gear 17 rotates in the forward direction, under the action of the one-way bearing 26, the driven gear 19 is considered to be fixedly connected to the short shaft 20. At this time, the ring gear 17 will drive the short shaft 20 to rotate through the driven gear 19. During the rotation of the short shaft 20, since the insert 15 is fitted in the slot 21 on the end face of the short shaft 20, the short shaft 20 will drive the insert 15 to rotate, thereby causing the feeding screw 8 to rotate to transport the external soil into the spiral pile 5.

[0048] When the ring gear 17 is rotated in the opposite direction to reset, under the action of the one-way bearing 26, the driven gear 19 is regarded as being rotatably connected to the short shaft 20 and will not drive the short shaft 20 to rotate, so as to prevent the feeding screw 8 from rotating in the opposite direction.

[0049] Installation process:

[0050] When supporting the inner wall of the foundation pit, the helical piles 5 are driven into the inner wall of the foundation pit using a power hydraulic device.

[0051] The isolation block 10 and two feeding screws 8 are installed into the spiral pile 5, with the feeding screws 8 installed into the pipe fitting 7, and the isolation block 10 is moved until the opening 25 aligns with the through hole 501.

[0052] After aligning the opening 25 with the through hole 501, the drive structure is installed into the port of the helical pile 5, the slot 21 on its short shaft 20 is aligned with the insert block 15, the pile cap 4 is then fitted onto the helical pile 5, and the first bolt 11 is installed into the through hole 501 and tightened.

[0053] The installation is completed by fixing the second bolt 201 on the heat-conducting plate 2 into the mounting hole 101 on the slope protection plate 1.

[0054] Working principle:

[0055] During the day, with ample sunlight, the surface of the slope protection panel 1 is coated with black to absorb solar energy and heat itself up. After the slope protection panel 1 heats up, the heat is transferred to the interior of the helical pile 5 through the heat-conducting plate 2 and heat-conducting column 3, thus heating the internal space of the helical pile 5 between the isolation block 10 and the pile cap 4. At night, when the ambient temperature drops, the excellent heat dissipation effect of the heat-conducting plate 2 and heat-conducting column 3 allows the internal space of the helical pile 5 to cool down.

[0056] Under temperature changes, the spiral-shaped memory metal wire 24 drives the guide block 22 to slide back and forth within the guide groove 23. During this back-and-forth movement, the guide block 22 drives the ring gear 17 to rotate in both the forward and reverse directions.

[0057] When the ring gear 17 rotates in the forward direction, under the action of the one-way bearing 26, the driven gear 19 is considered to be fixedly connected to the short shaft 20. At this time, the ring gear 17 will drive the short shaft 20 to rotate through the driven gear 19. During the rotation of the short shaft 20, since the insert 15 is fitted in the slot 21 on the end face of the short shaft 20, the short shaft 20 will drive the insert 15 to rotate. The rotation of the insert 15 will drive the extension shaft 12 to rotate. The rotation of the extension shaft 12 will drive the feeding screw 8 to rotate. During the rotation of the feeding screw 8, the soil near the spiral blades on the spiral pile 5 will be transported into the spiral pile 5.

[0058] After the soil near the helical blades is transported to the helical pile 5, the soil around the helical blades becomes loose. When the soil freezes and causes volume expansion, the loose soil structure around the helical blades leaves enough space for expansion to prevent the helical blades from being deformed or damaged due to the expansion of the soil between the pitches of the helical blades along the axial direction of the helical pile 5.

[0059] In addition, as the feeding screw 8 transports soil into the interior of the helical pile 5, the interior of the helical pile 5 will also be filled with soil. When the soil outside the helical pile 5 freezes, the frozen soil outside will exert a radial force on the helical pile 5 from the outside. Meanwhile, the soil inside the helical pile 5 will also freeze and expand under the action of low temperature, exerting a radial force on the helical pile 5 from the inside, so as to balance the forces inside and outside the helical pile 5 and thus prevent the helical pile 5 from deforming.

[0060] When the ring gear 17 is rotated in the opposite direction to reset, under the action of the one-way bearing 26, the driven gear 19 is regarded as being rotatably connected to the short shaft 20 and will not drive the short shaft 20 to rotate, so as to prevent the feeding screw 8 from rotating in the opposite direction.

[0061] Disassembly process:

[0062] After construction is completed, first open the second bolt 201 to remove the slope protection plate 1, and then open the first bolt 11 to remove the pile cap 4 from the helical pile 5.

[0063] Use pliers to reach inside the helical post 5 and remove the drive structure from inside the helical post 5.

[0064] The insert block 15 is subjected to the elastic force of the compression spring 14. Under the action of the elastic force, the insert block 15 can extend out from the end opening of the spiral pile 5. The construction personnel apply force to the insert block 15 to pull the feeding screw 8 out of the spiral pile 5.

[0065] During the process of the feeding screw 8 being pulled out, the soil in the receiving cavity will be cleaned out.

[0066] The helical pile 5 is driven to reverse using a power hydraulic device until it is pulled out of the soil, thus completing the dismantling work.

[0067] Compared with the prior art, the deep foundation pit helical pile support system provided by the present invention transports the soil near the helical blades to the helical pile 5 through the feeding screw 8, which makes the soil around the helical blades loose. When the soil freezes and causes volume expansion, the loose soil structure around the helical blades leaves enough space for the soil to expand, so as to prevent the helical blades from being deformed or damaged due to the expansion of the soil between the pitches of the helical blades along the axial direction of the helical pile 5.

[0068] When the soil outside the helical pile 5 freezes, the soil inside the helical pile 5 will also freeze and expand under the action of low temperature, applying radial force to the helical pile 5 from the inside, so as to balance the forces inside and outside the helical pile 5 and thus prevent the helical pile 5 from deforming.

[0069] 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 deep foundation pit spiral pile support system, characterized in that, The system includes a spiral pile (5), which has two parallel pipe fittings (7) fixedly connected inside. A feeding screw (8) is inserted inside the pipe fitting (7). A cone head (9) is fixedly connected to one end of the feeding screw (8), and an extension shaft (12) is fixedly connected to the other end of the feeding screw (8). A pile cap (4) is fitted at the end of the spiral pile (5). A through hole (501) is opened radially through the end of the spiral pile (5). The pile cap (4) is fixed in the through hole (501) by a first bolt (11). A connecting structure is provided inside the pile cap (4) to connect the slope protection plate (1). The spiral pile (5) is provided with a partition structure to divide the spiral pile (5) into a receiving cavity. The partition structure includes a connecting block (6) and a separating block (10). The shape of the connecting block (6) matches the spiral pile (5), and the connecting block (6) is fixed to the end of the pipe fitting (7). The separating block (10) is slidably fitted inside the spiral pile (5). The separating block (10) has a hole (25) that runs radially through it to accommodate the passage of the first bolt (11). The isolation block (10) has a sliding hole (13) inside. The end of the extension shaft (12) is slidably fitted in the sliding hole (13) and fixed with a frustum-shaped insert (15). A compression spring (14) is provided in the sliding hole (13) to apply elastic force to the insert (15). The spiral pile (5) is provided with a driving structure to drive the insertion block (15) to rotate. The driving structure includes a front panel (18), a rear panel (16) and a short shaft (20). The front panel (18) and the rear panel (16) are slidably fitted in the spiral pile (5). One end of the short shaft (20) is rotatably connected to the front panel (18), and the other end of the short shaft (20) is rotatably connected to the rear panel (16). The front panel (18) is provided with an arc-shaped guide groove (23). A guide block (22) is slidably fitted in the guide groove (23). A ring gear (17) is rotatably installed on the surface of the rear panel (16). The guide block (22) is fixedly connected to the end face of the ring gear (17). A memory metal wire (24) is provided in the guide groove (23) to drive the guide block (22) to move.

2. The deep foundation pit spiral pile support system according to claim 1, characterized in that, The connection structure includes a heat-conducting plate (2), a second bolt (201) is fixedly connected to one side of the heat-conducting plate (2), an installation hole (101) is opened through the slope protection plate (1), the second bolt (201) is connected to the installation hole (101), a heat-conducting column (3) is fixedly connected to the other side of the heat-conducting plate (2), the heat-conducting column (3) is fixedly connected to the pile cap (4) and extends into the helical pile (5).

3. The deep foundation pit spiral pile support system according to claim 1, characterized in that, The short shaft (20) has a driven gear (19) connected to the middle of its outer wall via a one-way bearing (26), and the driven gear (19) is matched with the ring gear (17).

4. The deep foundation pit spiral pile support system according to claim 3, characterized in that, One end of the short shaft (20) passes through the rear panel (16) and has a frustum-shaped slot (21) on the end face. The insert (15) cooperates with the slot (21).

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