A recyclable drainage soil nail device and construction method

Abstract

The application discloses a recyclable drainage soil nail device and a construction method. The drainage soil nail device comprises a sleeve rod assembly and a top rod. The sleeve rod assembly comprises a main sleeve pipe which is in a cylindrical shape as a whole. The main sleeve pipe is connected with an end sleeve pipe at one end, and the end sleeve pipe is closed in a conical shape. The main sleeve pipe is provided with a barb piece arranged in an axial direction. One end of the barb piece is rotatably installed on the main sleeve pipe through a hinge shaft which is perpendicular to the axis of the main sleeve pipe. The main sleeve pipe is further provided with a clearance slot which is arranged correspondingly to the barb piece. The barb piece is provided with a top contact part which protrudes towards the middle part of the main sleeve pipe in a radial direction. The minimum distance between the top contact part and the axis of the main sleeve pipe is smaller than the radius of the top rod. When the top rod is inserted into the main sleeve pipe, the barb piece can be turned out of the clearance slot in a radial direction of the main sleeve pipe. The barb piece is arranged in a plurality of intervals along the length direction of the main sleeve pipe, and is arranged in a circumferential distribution along the main sleeve pipe. The recyclable drainage soil nail device has the advantages of ingenious structure design, recycling and reusing after the completion of the project and the like.

Description

Technical Field

[0001] This invention relates to the field of foundation pit excavation and slope protection technology, and in particular to a recyclable drainage soil nailing device and its construction method. Background Technology

[0002] The protection of foundation pits in urban construction has always been a concern. Due to the limited land area of ​​urban buildings, it is obviously unreasonable to use sloping methods to prevent the foundation pit from sliding. Currently, soil nailing is widely used as a reinforcement measure in fields such as foundation pit and slope protection. As a new retaining technology for stabilizing building foundation pits and slopes, soil nailing has been widely applied due to its economical, reliable, and quick and simple construction. Soil nailing fully utilizes the strength of the foundation soil itself, achieving the purpose of support by simultaneously excavating the soil and installing soil nails. The stress characteristics of soil nails differ from those of anchor rods. Anchor rods generally have a free section and an anchored section, providing greater pull-out resistance through the anchored section in the soil at the far end. Soil nails, on the other hand, are usually shorter than anchor rods and generally experience less tensile force. The conventional approach is to grout the entire length of the hole, with a steel bar installed in the middle. The grout and the steel bar are bonded together to form a cylindrical whole to bear the tensile load. At this time, both the grout and the steel bar are under tension. When the slope is excavated downwards, the soil deforms, causing the soil nails to bear pull-out force, thereby reinforcing the slope soil.

[0003] Existing soil nailing walls for foundation pit protection typically employ drilling and grouting methods. The drilling process causes significant disturbance to the original soil. Furthermore, after construction, the reinforcing steel bars inside the soil nailing wall are bonded to the soil by concrete and cannot be recycled. This results in a large amount of steel bars remaining underground, becoming permanent obstacles and posing safety hazards for future foundation construction in surrounding areas. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is: how to provide a drainage soil nailing device and construction method with ingenious structural design that can be recycled after construction.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A recyclable drainage soil nailing device is characterized by comprising a sleeve assembly and a top rod. The sleeve assembly includes a main sleeve that is cylindrical in shape, with one end of the main sleeve connected to an end sleeve that is tapered and closed. The main sleeve has axially arranged barbs inside, one end of which is rotatably mounted on the main sleeve via a hinge perpendicular to the axis of the main sleeve. The main sleeve also has a clearance groove corresponding to the barbs. The barbs have a top contact portion protruding radially toward the center of the main sleeve. The minimum distance between the top contact portion and the axis of the main sleeve is less than the radius of the top rod, allowing the top rod to pass through the main sleeve and rotate the barbs radially outward out of the clearance groove. Multiple barbs are spaced apart along the length of the main sleeve, and the multiple barbs are distributed circumferentially along the main sleeve.

[0007] In use, drive the end sleeve into the soil with the end sleeve facing the soil layer. After the sleeve assembly is driven into the soil, insert the top rod through the rear end of the main sleeve and drive it inward. Once the top rod encounters the top contact of the barb, the barb will rotate out of the clearance groove and be driven into the soil, forming a reliable connection. At this time, because the top rod is inside the main sleeve, the barb cannot be retracted, and the main sleeve can be firmly fixed in the soil by the barb driven into the soil. During disassembly, pull the top rod out of the main sleeve, and then pull out the main sleeve and the end sleeve. At this time, the barb is not obstructed by the top rod and can be smoothly retracted during the pulling out of the main sleeve, allowing the main sleeve to be successfully retrieved.

[0008] Furthermore, the end of the main sleeve opposite to the end sleeve is connected to a threaded sleeve with external threads, and a locking nut is fitted on the threaded sleeve; the sleeve assembly also includes a collar for connecting the reinforcing mesh, the inner diameter of the collar matching the outer diameter of the threaded sleeve.

[0009] When using it, after the top rod is driven into the main sleeve, put the collar on the threaded sleeve, then screw the lock nut on the threaded sleeve and tighten it against the collar, and connect the steel mesh to the collar to complete the fixing of the steel mesh.

[0010] Furthermore, the main sleeve has a coaxially arranged centering ring, the inner diameter of which matches the outer diameter of the push rod.

[0011] In this way, the centering ring that matches the push rod can ensure that the push rod and the main sleeve remain coaxial when the push rod is inserted into the main sleeve. This facilitates the smooth insertion of the push rod and ensures that the push rod can reliably push out the barbed part.

[0012] Furthermore, the main sleeve includes at least two coaxially connected sleeves, each sleeve being provided with the barb and the centering ring; one end of the sleeve has a connecting section with a smaller diameter, the connecting section being provided with an external thread, and the other end of the sleeve has an internal thread that matches the external thread.

[0013] In this way, multiple sleeves can be connected in sequence to form a main sleeve, which can meet the needs of different depths.

[0014] Furthermore, the centering ring is located at the end of the sleeve and extends outward to form the connecting section.

[0015] In this way, a centering ring with a relatively small outer diameter can be used to connect two sleeves without thinning the sleeves, making the processing simpler.

[0016] Furthermore, the barb is a fan-shaped barb plate, with one end of the barb plate facing the center of the fan shape hinged to the main sleeve and the other end facing the end sleeve.

[0017] In this way, since the barb is fan-shaped and the end facing the center of the fan faces outward, when the barb is fully retracted into the main sleeve, the side of the barb facing the middle forms an outward inclined guide surface, so that the barb can be better pushed out when the push rod is inserted.

[0018] Furthermore, each of the sleeves has two sets of barbs spaced apart along the axial direction, each set of barbs including two barbs symmetrically arranged radially along the main sleeve; the two sets of barbs are offset by 90° in the circumferential direction of the main sleeve.

[0019] Furthermore, the end of the relief groove facing the end sleeve is covered with a puncturable baffle.

[0020] In this way, the baffle plate can prevent the main bushing from rotating out of the clearance groove during the driving process, thus affecting the smooth driving of the main bushing.

[0021] Furthermore, an elastic buffer device is provided axially inside the end sleeve; the main sleeve has water-permeable holes and a filter membrane covering the water-permeable holes inside.

[0022] Since the push rod and the main sleeve may stick together after use, the push rod needs to be hammered inward again to separate it from the main sleeve so that it can be pulled out. Additionally, a drain pipe can be formed using the permeable holes on the main sleeve, eliminating the need for additional drain holes.

[0023] A method for constructing soil nails, characterized in that, before construction, a recyclable drainage soil nail device as described above is first obtained; during construction, according to the measured points, the sleeve assembly is driven in, keeping the sleeve assembly in a horizontal state or with the outer end tilted downwards; then, the top rod is driven into the main sleeve of the sleeve assembly, and after the soil nail device is fixed, a steel mesh is laid and connected to the soil nail device; after the outer end of the sleeve assembly is wrapped, concrete grout is sprayed.

[0024] Compared with the prior art, the drainage soil nailing device and construction method of the present invention have the following advantages:

[0025] 1. Eliminates the need for excavation and grouting. Based on existing foundation pit soil nailing wall construction technology, this invention utilizes the barbed structure formed by the soil nails themselves in the soil to generate sufficient pull-out resistance, thereby eliminating the two cumbersome steps of excavation and grouting and greatly improving construction speed.

[0026] 2. Minimal soil disturbance. Because this invention directly drives the sleeve assembly into the soil, compared to the traditional process of excavating holes and then grouting, it significantly reduces soil disturbance.

[0027] 3. Recyclable and reusable. Currently, most soil nailing walls in foundation pits leave a large amount of reinforcing steel bars underground after construction, wasting materials and creating safety hazards for future foundation construction in surrounding areas. This invention provides a recyclable soil nailing device that can be removed after construction, enabling its reuse and effectively reducing costs.

[0028] 4. Drainage capability. The main sleeve of the soil nailing device designed in this invention is equipped with drainage holes and a filter membrane, which can effectively drain water from the wall, eliminating the need for a separate drainage pipe installation in the wall, increasing construction speed, and reducing the construction period.

[0029] 5. Adjustable length. Addressing the limitation of most existing soil nails having a uniform length and thus lacking flexibility, the soil nailing device designed in this invention features insert rods that are assembled on-site from unit rods, allowing for flexible and adaptable lengths, while also facilitating maintenance and replacement. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the drainage soil nailing device.

[0031] Figure 2 This is a structural diagram of each part of the sleeve assembly.

[0032] Figure 3 This is a schematic diagram of the structure of the barbed part in its retracted state.

[0033] Figure 4 This is a schematic diagram of the structure of the barbed component in the open state.

[0034] Figure 5 This is a schematic diagram of the push rod and buffer device.

[0035] Figure 6 This is a schematic diagram of the soil nailing device being driven into the soil layer.

[0036] Figure 7 This is a schematic diagram of the demolition process. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the embodiments.

[0038] In practical implementation: such as Figures 1-5 As shown, a recyclable drainage soil nailing device includes a sleeve assembly 1 and a top rod 2. The sleeve assembly 1 includes a main sleeve 11 that is integrally cylindrical, with permeable holes and a filter membrane covering the permeable holes inside. One end of the main sleeve 11 is connected to an end sleeve 12 with a tapered and closed end. The main sleeve 11 has axially arranged barbs 13 inside, one end of which is rotatably mounted on the main sleeve 11 via a hinge perpendicular to the axis of the main sleeve 11. The main sleeve 11 also has… The sleeve assembly has a clearance groove corresponding to the barb 13; the barb 13 has a top contact portion protruding radially toward the center of the main sleeve 11, the minimum distance between the top contact portion and the axis of the main sleeve 11 is less than the radius of the push rod 2, so that the push rod 2 can be inserted into the main sleeve 11 and rotate the barb 13 radially outward from the clearance groove; multiple barbs 13 are spaced apart along the length of the main sleeve 11, and the multiple barbs 13 are distributed circumferentially along the main sleeve 11. The end of the main sleeve 11 opposite to the end sleeve 12 is connected to a threaded sleeve 14 with external threads, and a locking nut 15 is fitted on the threaded sleeve 14; the sleeve rod assembly also includes a collar 16 for connecting the reinforcing mesh, the inner diameter of the collar 16 matching the outer diameter of the threaded sleeve 14. An elastic buffer device 4 is provided axially inside the end sleeve 12. In this embodiment, the buffer device consists of a baffle and multiple springs arranged axially along the end sleeve 12. Figure 5 As shown.

[0039] During construction, the sleeve assembly is driven in according to the measured points, with the threaded sleeve of the sleeve assembly exposed. The sleeve assembly is kept horizontal or tilted downwards at the outer end to facilitate drainage. The top rod 2 is driven into the main sleeve, and the barb is pushed out and inserted into the soil to fix the sleeve assembly. Due to the buffer device installed in the end sleeve, the top rod will retract under the action of the buffer device after being fully driven in, maintaining the pushing space between the front end of the top rod and the front end of the end sleeve. After fixing the sleeve assembly, the collar is placed on the threaded sleeve, and the lock nut is tightened, allowing the lock nut to press against the collar. A reinforcing mesh is laid and fixed to the collar. The connection between the lock nut and the sleeve is wrapped to prevent concrete from solidifying the lock nut and collar. After the reinforcing mesh is laid, shotcrete is sprayed to complete the soil nailing. After the foundation pit work is completed, the top rod is hammered again, using the pushing space between the top rod and the front end of the end sleeve to loosen the top rod and the barb device, and then the top rod is pulled out. Then unscrew the lock nut and pull out the sleeve assembly.

[0040] To prevent the barbs from rotating out during the insertion of the main sleeve and affecting the main sleeve, this embodiment provides a puncturable baffle at one end of the relief groove facing the end sleeve 12.

[0041] In addition, the main sleeve 11 includes at least two coaxially connected sleeves, each sleeve being provided with the barb 13 and the centering ring 3; one end of each sleeve has a connecting section with a smaller diameter and an external thread, and the other end of each sleeve has an internal thread that matches the external thread. Multiple sleeves can be spliced ​​together to meet different construction depth requirements. To prevent material corrosion from affecting its service life, nickel plating is used during the prefabrication of each part in the factory, greatly improving the material's corrosion resistance.

[0042] To ensure the push rod remains aligned during insertion into the main sleeve, the main sleeve 11 has a coaxially arranged alignment ring 3, the inner diameter of which matches the outer diameter of the push rod 2. In a specific implementation, the alignment ring 3 can also be positioned at the end of the sleeve and extend outwards to form the connecting section. This allows for the connection of two sleeves using an alignment ring with a relatively small outer diameter, eliminating the need to thin the sleeves and simplifying the manufacturing process.

[0043] As shown in the figure, the barb 13 is a fan-shaped barb plate. One end of the barb plate facing the center of the fan is hinged to the main sleeve 11, and the other end faces the end sleeve 12. Each sleeve has two sets of barbs 13 spaced apart along the axial direction. Each set of barbs 13 includes two barbs 13 symmetrically arranged radially along the main sleeve 11. The two sets of barbs 13 are offset by 90° in the circumferential direction of the main sleeve 11.

[0044] In this way, since the barb is fan-shaped and the end facing the center of the fan faces outward, when the barb is fully retracted into the main sleeve, the side of the barb facing the middle forms an outward inclined guide surface, so that the barb can be better pushed out when the push rod is inserted.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A recyclable drainage soil nailing device, characterized in that, The assembly includes a sleeve assembly (1) and a push rod (2). The sleeve assembly (1) includes a main sleeve (11) that is cylindrical in shape. One end of the main sleeve (11) is connected to an end sleeve (12) that is tapered and closed at the end. The main sleeve (11) has a barb (13) arranged axially inside. One end of the barb (13) is rotatably mounted on the main sleeve (11) via a hinge pin perpendicular to the axis of the main sleeve (11). The main sleeve (11) also has a relief groove corresponding to the barb (13). The barb (13) has a top contact portion that protrudes radially toward the center of the main sleeve (11). The minimum distance between the top contact portion and the axis of the main sleeve (11) is less than the radius of the push rod (2), so that the... The push rod (2) is inserted into the main sleeve (11) and can rotate the barb (13) outward along the radial direction of the main sleeve (11) out of the relief groove; the barb (13) is arranged in multiple intervals along the length direction of the main sleeve (11), and the multiple barb (13) are distributed along the circumference of the main sleeve (11); the main sleeve (11) has water-permeable holes, and has a filter membrane covering the water-permeable holes inside; the end sleeve (12) is provided with an elastic buffer device (4) along the axial direction. After the push rod (2) is fully driven in, the buffer device (4) can cause the push rod (2) to retract in the end sleeve (12), thereby forming a push-in space between the front end of the push rod (2) and the front end of the end sleeve (12).

2. The recyclable drainage soil nailing device as described in claim 1, characterized in that, The main sleeve (11) is connected to a threaded sleeve (14) with external threads at one end away from the end sleeve (12), and a locking nut (15) is fitted on the threaded sleeve (14); the sleeve assembly also includes a collar (16) for connecting the reinforcing mesh, the inner diameter of the collar (16) matching the outer diameter of the threaded sleeve (14).

3. The recyclable drainage soil nailing device as described in claim 1 or 2, characterized in that, The main sleeve (11) has a coaxially arranged centering ring (3), the inner diameter of which matches the outer diameter of the push rod (2).

4. The recyclable drainage soil nailing device as described in claim 3, characterized in that, The main sleeve (11) includes at least two coaxially connected sleeves, each sleeve being provided with the barb (13) and the centering ring (3); one end of the sleeve has a connecting section with a smaller diameter, the connecting section being provided with an external thread, and the other end of the sleeve has an internal thread that matches the external thread.

5. The recyclable drainage soil nailing device as described in claim 4, characterized in that, The centering ring (3) is located at the end of the sleeve and extends outward to form the connecting section.

6. The recyclable drainage soil nailing device as described in claim 4, characterized in that, The barb part (13) is a barb plate that is fan-shaped in whole. One end of the barb plate facing the center of the fan is hinged to the main sleeve (11), and the other end faces the end sleeve (12).

7. The recyclable drainage soil nailing device as described in claim 6, characterized in that, Each of the sleeves has two sets of barbs (13) spaced apart along the axial direction. Each set of barbs (13) includes two barbs (13) arranged symmetrically along the radial direction of the main sleeve (11). The two sets of barbs (13) are offset by 90° in the circumferential direction of the main sleeve (11).

8. The recyclable drainage soil nailing device as described in claim 6, characterized in that, The end of the relief groove facing the end sleeve (12) is covered with a puncturable baffle.

9. A method for constructing soil nails, characterized in that, Before construction, obtain the recyclable drainage soil nailing device as described in any one of claims 1 to 8. During construction, according to the measured points, drive the sleeve assembly in, keeping the sleeve assembly in a horizontal state or with the outer end tilted downwards; then drive the top rod into the main sleeve of the sleeve assembly to complete the fixation of the soil nailing device, lay the steel mesh, and connect the steel mesh to the soil nailing device; after wrapping the outer end of the sleeve assembly, spray concrete grout.

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