Single-stage and multi-stage tension expansion soil nails

Abstract

The present application relates to a single-stage and multi-stage tension expansion type soil nail, comprising a soil nail rod body, an expansion and reinforcement assembly arranged on the soil nail rod body; the expansion and reinforcement assembly comprises a limit pressure plate, a first expansion piece and an elastic member; the limit pressure plate is fixedly arranged with the soil nail rod body, one side of the first expansion piece is hingedly connected with the limit pressure plate, and the projection of the wide surface of the first expansion piece along the axial direction of the soil nail rod body is located on the surface of the limit pressure plate; the elastic member is used to force the free end of the first expansion piece to flip along the direction away from the axis of the soil nail rod body and along the insertion direction of the soil nail rod body, and the limit pressure plate blocks the flipping path of the first expansion piece; when the first expansion piece abuts against the limit pressure plate, the radial distance between the free end of the first expansion piece and the axis of the soil nail rod body is greater than the radial distance between the edge of the limit pressure plate and the axis of the soil nail rod body. The present application can effectively improve the pull-out resistance of the soil nail by setting the expansion and reinforcement assembly.

Description

Technical Field

[0001] The present application relates to a single-stage and multi-stage tension expansion type soil nail. Background Art

[0002] The traditional soil nail wall support system is a slope support structure composed of in-situ soil, soil nails, surface layer and drainage system. The soil nail rods are usually formed by solidification of high-strength materials (hot-rolled ribbed steel bars) and cement mortar or cement slurry, and are anchored in the soil. The surface layer is a wall or plate composed of a high-strength composite material (usually composed of steel mesh and shotcrete) with properties that are very different from the in-situ soil, and is connected to the soil nails to withstand the pressure of the soil layer behind it, limit the stress release of the soil, and restrain the deformation of the soil, thereby locking the soil together.

[0003] With regard to the above-mentioned related technologies, the inventor believes that, since the shear strength of the soil is low and the tensile strength is almost negligible, the natural soil can only stand upright at a relatively small height. When the standing height of the soil exceeds its critical height, the soil is at risk of moving downward along the potential rupture slip surface. Summary of the invention

[0004] In order to reduce the risk of soil moving downward along a potential rupture slip surface, the present application provides a single-stage and multi-stage tension-expansion soil nail.

[0005] The present application provides a single-stage and multi-stage tension expansion soil nail, which adopts the following technical solution:

[0006] A single-stage and multi-stage tension expansion type soil nail, comprising a soil nail rod body and an expansion and reinforcement component arranged on the soil nail rod body; the expansion and reinforcement component comprises a limit pressure plate, a first expansion piece and an elastic member; the limit pressure plate is fixedly arranged on the soil nail rod body, one side of the first expansion piece is hingedly connected to the limit pressure plate, and the projection of the wide surface of the first expansion piece along the axial direction of the soil nail rod body is located on the surface of the limit pressure plate; the elastic member is used to force the free end of the first expansion piece to flip along the direction away from the axis of the soil nail rod body and along the insertion direction of the soil nail rod body, and the limit pressure plate blocks the flipping path of the first expansion piece; when the first expansion piece abuts against the limit pressure plate, the radial distance between the free end of the first expansion piece and the axis of the soil nail rod body is greater than the radial distance between the edge of the limit pressure plate and the axis of the soil nail rod body.

[0007] When the vertical height of the soil exceeds its critical height, the soil will move downward along the potential rupture slip surface. At this time, the soil nails are subject to two forces: one is the tensile force and the other is the shear force of the soil. The tensile force of the soil nail is the friction force generated when the soil nail and the surrounding soil have a tendency to move relative to each other. Its magnitude depends on the friction coefficient between the soil nail and the surrounding soil and the length of the anchoring section. Traditional soil nails are passive force-bearing type. Only when the soil loses its self-stabilizing ability and has a tendency to move relative to each other, the soil nails can play a tensile and shearing role. The soil nail wall support system itself cannot improve the shearing capacity of the soil. In addition, a large number of examples of soil nail wall failure show that when the soil is destroyed, it is often not the soil nail rod that is sheared off, but it is pulled out of the soil behind the slip surface as a whole. This shows that the shear strength of the soil nail cannot be fully exerted, and the tensile effect is not enough to ensure the stability of the slip surface. The insufficient tensile capacity of the soil nail is caused by the insufficient anchoring force between the soil nail and the surrounding soil.

[0008] By adopting the above technical scheme, the pull-out resistance of the soil nail can be effectively improved to reduce the risk of the soil moving downward along the potential rupture slip surface; the specific method is as follows: in the process of inserting the soil nail rod into the hole, the inner wall soil of the hole forces the first expansion piece to flip inward (the elastic member is compressed and stressed), and when the soil nail rod is inserted to a predetermined depth, a certain tensile stress is applied to the soil nail rod. At this time, the first expansion piece will flip outward and penetrate into the soil under the action of the elastic member and the surrounding soil, and when the first expansion piece is close to the surface of the limiting pressure plate, that is, the first expansion piece flips to the maximum angle and the penetration depth of the first expansion piece is the largest, then cement slurry is injected into the hole, and after the cement slurry solidifies, a supporting reaction force is applied to the first expansion piece, and the supporting reaction force works together with the limiting pressure plate to ensure that the first expansion piece does not move. In this way, the expansion reinforcement component effectively increases the pull-out bearing capacity of the soil nail rod, and the expansion reinforcement component can be set in multiple stages, thereby further increasing the pull-out resistance of the soil nail rod. bearing capacity; and, when tensile stress is applied to the soil nail rod, the exposed part of the flipped first expansion piece causes certain damage to the surrounding soil during the movement of the soil nail rod, that is, a depression area is formed in the surrounding soil, and the subsequently injected cement slurry will fill the depression area to form a reinforced concrete structure, and the reinforced concrete structure can further improve the tensile resistance of the soil nail rod to reduce the risk of the soil moving downward along the potential rupture slip surface; when the pull-out bearing capacity of the soil nail is required to be high, simply increasing the diameter and length of the soil nail can meet the requirements, but the cost increase is large, and the above scheme can be used in this case to effectively reduce the construction cost; the traditional soil nail wall is generally required to be no more than 12m deep. After applying this scheme, it is possible to increase the application depth of the soil nail wall on the basis of effectively increasing the pull-out bearing capacity of the soil nail. Because the cost of the soil nail wall is much lower than other support forms such as anchor piles, the promotion and use of this scheme can create better economic benefits to a certain extent.

[0009] Optionally, the number of the first expansion pieces is multiple, and the first expansion pieces are evenly arranged around the circumference of the soil nail rod body.

[0010] By adopting the above technical solution, the force exerted on the first expansion piece from the surrounding soil will be evenly applied to the soil nail rod body, thereby improving the coaxiality between the soil nail rod body and the formed hole.

[0011] Optionally, the free end of the first expansion piece is bent outwardly in a direction away from the axis of the soil nail rod body to form a sharp portion, and the thickness of the sharp portion gradually increases in a direction toward the hinged end of the first expansion piece.

[0012] By adopting the above technical solution, firstly, the setting of the sharp portion can improve the ease of penetration of the first expansion piece, thereby facilitating the flipping and opening of the first expansion piece; secondly, when tensile stress is applied to the soil nail rod body, the bearing area of ​​the bent sharp portion is larger, so the force exerted on it from the surrounding soil is larger, making it easier to flip and open the first expansion piece.

[0013] Optionally, the expansion enhancement assembly also includes a sleeve fixed on the soil nail rod body, a hook ring is provided on the wide surface of the first expansion piece facing away from the limiting pressure plate, the elastic member is a first compression spring, one end of the first compression spring is connected to the sleeve, and the other end of the first compression spring is connected to the hook ring.

[0014] By adopting the above technical solution, the first expansion piece can be driven to flip outwards by the elastic force of the first compression spring.

[0015] Optionally, it also includes a traction rope, and the sleeve is connected to a slider along its own circumferential sliding direction, and the slider is provided with a first support rod for the traction rope to pass around, and the traction rope drives the slider to slide when it is tightened along the axial direction of the soil nail rod body; the slider is fixed with a bracket, and the bracket is fixed with a first limit block, and the sliding path of the first limit block interferes with the flipping path of the first expansion piece; when the first limit block abuts against the wide surface of the first expansion piece away from the soil nail rod body, the projection of the first expansion piece along the axial direction of the soil nail rod body is completely located on the surface of the limit pressure plate.

[0016] By adopting the above technical scheme, before the soil nail rod body is inserted into the hole, first ensure that the first limit block abuts against the wide surface of the first expansion piece away from the soil nail rod body to prevent the first expansion piece from flipping over, thereby reducing the situation where the first expansion piece penetrates into the surrounding soil due to excessive flipping, thereby reducing the frictional resistance of the soil nail rod body during the insertion of the hole; when the soil nail rod body is inserted to a predetermined depth, the traction rope is pulled along the axial direction of the soil nail rod body to drive the slider to slide a certain distance along the circumferential direction of the soil nail rod body, so that the first limit block is disengaged from the abutment relationship, the first expansion piece is unobstructed and can be flipped freely, thereby facilitating the first expansion piece to penetrate into the soil.

[0017] Optionally, the expansion enhancement assembly also includes a second expansion piece arranged at a position corresponding to the first expansion piece, one side of the second expansion piece is hingedly connected to the surface of the limiting pressure plate facing away from the first expansion piece, and a second compression spring is provided between the second expansion piece and the sleeve, and the second compression spring is used to force the free end of the second expansion piece to flip in a direction away from the axis of the soil nail rod body and toward the limiting pressure plate, and the limiting pressure plate blocks the flipping path of the second expansion piece; the bracket is fixed with a second limiting block, and the sliding path of the second limiting block interferes with the flipping path of the second expansion piece; when the second limiting block abuts against the wide surface of the second expansion piece facing away from the soil nail rod body, the projection of the second expansion piece along the axial direction of the soil nail rod body is completely located on the surface of the limiting pressure plate.

[0018] By adopting the above technical scheme, before the soil nail rod body is inserted into the hole, first ensure that the second limit block abuts against the wide surface of the second expansion piece away from the soil nail rod body to prevent the second expansion piece from turning over, thereby reducing the situation where the second expansion piece is inserted into the surrounding soil due to excessive turning over, and further reducing the frictional resistance during the insertion of the soil nail rod body into the hole; when the soil nail rod body is inserted to a predetermined depth, the traction rope is pulled axially along the soil nail rod body to drive the slider to slide a certain distance along the circumferential direction of the soil nail rod body, so that the second limit block and the first limit block are respectively separated from the abutment relationship, and the first expansion piece and the second expansion piece are unobstructed and can be turned over freely, thereby facilitating the first expansion piece and the second expansion piece to penetrate into the soil; and the combination of the first expansion piece and the second expansion piece in the opened state can improve the strength of the structure penetrated into the soil, thereby improving the pull-out resistance of the soil nail.

[0019] Optionally, the bracket is fixed with an arc rod located on the outer peripheral side of the limit pressure plate, the center of curvature of the arc rod is located at the axis of the soil nail rod body, and the wide surfaces of the first expansion piece and the second expansion piece are fixed with limiting ring sleeves through which the arc rod can pass; when the first expansion piece and the second expansion piece are in contact with the limit pressure plate, the axis center of the limiting ring sleeve thereon coincides with the moving path of the arc rod.

[0020] By adopting the above technical solution, when the first expansion piece and the second expansion piece are both in a fully opened state, the support rod is driven to slide by a traction rope, so that the arc rod is simultaneously inserted into the limiting ring sleeves on the first expansion piece and the second expansion piece, that is, the first expansion piece and the second expansion piece in the opened state are simultaneously limitedly connected, so as to improve the structural strength of the expansion reinforcement assembly and reduce the occurrence of the first expansion piece or the second expansion piece being broken due to excessive pulling force.

[0021] Optionally, a reinforcement ring is fixed to the circumferential surface of the position-limiting pressure plate, and the axis of the reinforcement ring coincides with the moving path of the arc rod.

[0022] By adopting the above technical solution, the arc rod is inserted into the limiting ring sleeves on the reinforcement ring, the first expansion piece and the second expansion piece at the same time, that is, the limiting pressure plate, the first expansion piece and the second expansion piece in the open state are simultaneously limited and connected, so that the three become one, so as to improve the structural strength of the expansion reinforcement assembly, thereby further improving the pull-out resistance of the soil nails.

[0023] Optionally, a deviation-correcting block is fixed to the bracket, and the shortest distance between the deviation-correcting block and the limit pressure plate is equal to the thickness of the first expansion piece.

[0024] By adopting the above-mentioned technical solution, when the first expansion piece is close to the surface of the limiting pressure plate, the bracket can be controlled to slide to drive the correction block to move, so that the correction block is against the wide surface of the first expansion piece, thereby improving the limiting effect on the first expansion piece, thereby reducing the occurrence of the first expansion piece or the second expansion piece breaking due to excessive pulling force.

[0025] Optionally, a resistance-enhancing strip is protruding from a surface of the sharp portion facing away from the limiting pressure plate.

[0026] By adopting the above technical solution and providing the resistance increasing strip, the roughness of the surface of the sharp portion can be increased. Therefore, when the soil nail rod is pulled back, the friction force of the surrounding soil on the first expansion piece is greater, so that it can be more easily penetrated into the soil.

[0027] In summary, the present application includes at least one of the following beneficial technical effects:

[0028] By setting up a single-stage or multi-stage expansion and reinforcement component, the pull-out bearing capacity of the soil nail rod can be effectively increased to reduce the occurrence of soil slippage; and under the same pull-out bearing capacity requirements, compared with traditional soil nails, the combination of expansion and reinforcement components and soil nail rods can effectively reduce construction costs; traditional soil nail walls are generally required to be no more than 12m deep. After applying this solution, it is possible to increase the application depth of the soil nail wall on the basis of effectively increasing the pull-out bearing capacity of the soil nails. Since the cost of the soil nail wall is much lower than other support forms such as anchor piles, the promotion and use of this solution can create better economic benefits to a certain extent;

[0029] By setting a traction rope, the position movement of the bracket can be controlled, thereby controlling the first limit block and the second limit block to control the braking of the first expansion piece and the second expansion piece, thereby facilitating the insertion of the soil pile rod body and reducing the difficulty of the operation;

[0030] By providing a combination of the first expansion piece and the second expansion piece in the open state, the strength of the soil nail inserted into the structure can be increased, thereby improving the pull-out resistance of the soil nail; and, the arc rod can be used to simultaneously limit the pressure block, the first expansion piece in the open state, and the second expansion piece to improve the structural strength of the expansion reinforcement assembly, thereby reducing the occurrence of the first expansion piece or the second expansion piece breaking due to excessive pull-out force. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the first expansion piece of Example 1 in a retracted state.

[0032] Figure 2 It is a schematic diagram of the first expansion piece of Example 1 in an open state.

[0033] Figure 3 It is a top view of the overall structure of Example 2.

[0034] Figure 4 It is a schematic diagram of the first expansion piece of Example 3 in a retracted state.

[0035] Figure 5 yes Figure 4 Schematic diagram from another perspective.

[0036] Figure 6 It is a partial cross-sectional view of Example 3 for reflecting the relationship between the traction rope and the slider.

[0037] Figure 7 It is a schematic diagram of the first expansion piece and the second expansion piece of Example 3 both being in an open state.

[0038] Explanation of the reference numerals in the accompanying drawings: 1. limit pressure plate; 2. first expansion piece; 3. first compression spring; 4. second expansion piece; 10. soil nail rod body; 11. casing; 12. avoidance groove; 13. slide groove; 14. slider; 141. first support rod; 142. second support rod; 15. bracket; 151. first limit block; 152. second limit block; 153. correction block; 154. arc rod; 155. connecting ring; 16. reinforcement ring; 20. expansion reinforcement component; 21. sharp part; 22. resistance increasing strip; 23. limit ring sleeve; 30. traction rope; 41. second compression spring. DETAILED DESCRIPTION

[0039] The following is combined with Figure 1-7 This application is described in further detail.

[0040] When the vertical height of the soil exceeds its critical height, the soil will move downward along the potential rupture slip surface. At this time, the soil nails are subject to two forces: one is the tensile force, and the other is the shear force of the soil. The tensile force of the soil nail is the friction force generated when the soil nail and the surrounding soil have a relative movement tendency. Its magnitude depends on the friction coefficient between the soil nail and the surrounding soil and the length of the anchoring section. In addition, a large number of examples of soil nail wall failure show that when the soil is destroyed, it is often not the soil nail rod that is sheared off, but the soil nail rod is pulled out of the soil behind the slip surface as a whole. This shows that the tensile force of the soil nail is not enough to ensure the stability of the slip surface; in summary, the tensile bearing capacity of the soil nail greatly affects whether the soil moves downward along the potential rupture slip surface.

[0041] Therefore, Example 1 of the present application discloses a single-stage and multi-stage tension expansion soil nail. Figure 1 The single-stage and multi-stage tension expansion type soil nails include a soil nail rod body 10 and an expansion reinforcement component 20 arranged on the soil nail rod body 10.

[0042] After the soil nail rod body 10 is inserted into the hole, the expansion reinforcement component 20 can be unfolded and inserted into the surrounding soil to improve the tensile bearing capacity of the soil nail rod body 10, thereby effectively reducing the risk of the soil moving down along the potential rupture slip surface; and, according to the tensile resistance requirements, the expansion reinforcement component 20 can be set to multiple levels to more effectively improve the tensile resistance.

[0043] like Figure 1 As shown, the expansion enhancement assembly 20 includes a sleeve 11, a limit pressure plate 1, a first expansion piece 2 and an elastic member arranged corresponding to the first expansion piece 2, wherein the sleeve 11 is connected to the soil nail rod body 10 by threaded connection and / or welding, the limit pressure plate 1 is adapted to the cross-sectional shape of the hole, preferably circular, and the limit pressure plate 1 is coaxially fixedly connected to the sleeve 11.

[0044] like Figure 1 , Figure 2 As shown, the first expansion piece 2 is in the shape of a petal, and the wide surface of the first expansion piece 2 is projected along the axial direction of the soil nail rod body 10 and is located on the upper surface of the limiting pressure plate 1; there are multiple first expansion pieces 2, preferably three in this embodiment 1, and each first expansion piece 2 is evenly arranged around the circumference of the soil nail rod body 10; one side of the first expansion piece 2 is hingedly connected to the upper surface of the limiting pressure plate 1, and the free end of the first expansion piece 2 is bent outward and toward the limiting pressure plate 1 to form a sharp portion 21, the thickness of the sharp portion 21 gradually increases along the direction toward the hinged end of the first expansion piece 2, and the width of the sharp portion 21 gradually increases along the direction toward the hinged end of the first expansion piece 2.

[0045] like Figure 1As shown, the elastic member can be a compression spring or a tension spring. In this embodiment, the elastic member is a first compression spring 3, one end of the first compression spring 3 is connected to the outer wall of the sleeve 11, and the other end of the first compression spring 3 is connected to the hook ring on the wide surface of the first expansion piece 2; the elastic force of the first compression spring 3 can force the free end of the first expansion piece 2 to turn away from the axis of the soil nail rod body 10 and along the insertion direction of the soil nail rod body 10, and the elastic force makes the first expansion piece 2 close to the upper surface of the limit pressure plate 1, and, as shown in FIG. Figure 2 As shown, when the first expansion piece 2 abuts against the upper surface of the limiting pressure plate 1, the radial distance between the free end of the first expansion piece 2 and the axis of the soil nail rod body 10 is greater than the radial distance between the edge of the limiting pressure plate 1 and the axis of the soil nail rod body 10, that is, the free end of the first expansion piece 2 is exposed radially outside the limiting pressure plate 1.

[0046] During construction, the soil nail rod 10 is inserted into the hole, and the inner wall soil of the hole forces the first expansion piece 2 to turn inward (see Figure 1 ), at this time, the first compression spring 3 is compressed and stressed, and when the soil nail rod 10 is inserted to a predetermined depth, a certain tensile stress is applied to the soil nail rod 10, and at this time, the first expansion piece 2 will be turned outward by the force of the first compression spring 3 and the surrounding soil and penetrate into the soil. When the first expansion piece 2 is close to the surface of the limit pressure plate 1, the first expansion piece 2 is turned to the maximum angle (see Figure 2 ), and the penetration depth of the first expansion piece 2 is the largest, and then cement slurry is injected into the hole. After the cement slurry solidifies, a supporting reaction force is applied to the first expansion piece 2. The supporting reaction force works together with the limiting pressure plate 1 to ensure that the first expansion piece 2 does not move. In this way, the expansion reinforcement component 20 effectively increases the pull-out bearing capacity of the soil nail rod body 10.

[0047] Furthermore, when tensile stress is applied to the soil nail rod body 10, the exposed portion of the flipped first expansion piece 2 causes certain damage to the surrounding soil during the movement of the soil nail rod body 10, that is, a depression is formed in the surrounding soil, and the subsequently injected cement slurry will fill the depression to form a reinforced concrete structure. The reinforced concrete structure can further improve the tensile strength of the soil nail rod body 10 to reduce the risk of the soil moving downward along the potential rupture slip surface.

[0048] Embodiment 2, as Figure 3 As shown, the surface of the sharp portion 21 facing away from the limiting pressure plate 1 is protruded with a resistance increasing strip 22, and the resistance increasing strip 22 can increase the roughness of the surface of the sharp portion 21. Therefore, when the soil nail rod 10 is pulled back, the friction force of the surrounding soil on the first expansion piece 2 is greater, so that the friction force can more easily drive the first expansion piece 2 to penetrate into the soil.

[0049] Example 3, based on Example 1, the following settings are added: Figure 4 , Figure 5As shown, the expansion enhancement component 20 also includes a second expansion piece 4 arranged at a position corresponding to the first expansion piece 2, the shape of the second expansion piece 4 is consistent with the shape of the first expansion piece 2, and one side of the second expansion piece 4 is hingedly connected to the lower surface of the limiting pressure plate 1; a second compression spring 41 is provided between the second expansion piece 4 and the sleeve 11, and the second compression spring 41 forces the free end of the second expansion piece 4 to flip along the direction away from the axis of the soil nail rod body 10 and toward the limiting pressure plate 1, and the elastic force makes the second expansion piece 4 close to the lower surface of the limiting pressure plate 1, and when the second expansion piece 4 abuts against the lower surface of the limiting pressure plate 1, the free end of the second expansion piece 4 is exposed radially outward of the limiting pressure plate 1.

[0050] like Figure 5 As shown, the soil nail rod body 10 is also provided with a traction rope 30, the lower end of the traction rope 30 is fixedly connected to the lower end of the soil nail rod body 10, and an avoidance groove 12 for the traction rope 30 to pass through is axially penetrated at a portion of the limiting pressure plate 1 close to the sleeve 11, and the upper end of the traction rope 30 is located outside the hole of the hole to facilitate pulling.

[0051] like Figure 6 As shown, a slide groove 13 is provided at a portion of the casing 11 located in the avoidance groove 12, and the slide groove 13 is arranged along the circumference of the casing 11. A slider 14 is slidably connected in the slide groove 13, and a first support rod 141 is fixed to the side wall of the slider 14. Two second support rods 142 are fixed to the outer wall of the casing 11, and the two second support rods 142 are symmetrically arranged up and down with the slide groove 13 as the center. The traction rope 30 is sequentially passed around a second support rod 142, a first support rod 141 and another second support rod 142. Therefore, when the traction rope 30 is tightened along the axial direction of the soil nail rod body 10, the force exerted by the traction rope 30 on the first support rod 141 will drive the slider 14 to slide a certain distance along the circumference of the casing 11.

[0052] like Figure 5 , Figure 6 As shown, the slider 14 is fixed with three frame-shaped brackets 15 through a connecting ring 155, the bracket 15 is arranged corresponding to the first expansion piece 2, and the limiting pressure plate 1 is located in the hollow position of the bracket 15; the bracket 15 is located on the upper surface of the limiting pressure plate 1 and is fixed with a first limiting block 151, and the first limiting block 151 is extended toward the direction of the adjacent first expansion piece 2; the bracket 15 is located on the lower surface of the limiting pressure plate 1 and is fixed with a second limiting block 152, and the second limiting block 152 is extended toward the direction of the adjacent second expansion piece 4.

[0053] like Figure 6 , Figure 7 As shown, the bracket 15 is also fixed with a correction block 153, which is extended away from the first limit block 151, and the shortest distance between the correction block 153 and the upper surface of the limit pressure plate 1 is equal to the thickness of the first expansion piece 2.

[0054] Before inserting the soil nail rod body 10 into the hole, first ensure that the first limit block 151 abuts against the wide surface of the first expansion piece 2 facing away from the soil nail rod body 10, and the second limit block 152 abuts against the wide surface of the second expansion piece 4 facing away from the soil nail rod body 10, so as to prevent the first expansion piece 2 and the second expansion piece 4 from turning over (at this time, the first expansion piece 2 and the second expansion piece 4 are both in a retracted state), thereby reducing the occurrence of the first expansion piece 2 and the second expansion piece 4 piercing into the surrounding soil due to excessive turning over, thereby reducing the frictional resistance of the soil nail rod body 10 during the insertion of the soil nail rod body 10 into the hole; when the soil nail rod body 10 is inserted to a predetermined depth, the traction rope 30 is pulled axially along the soil nail rod body 10 to drive the slider 14 to drive the soil nail rod body 10 to slide circumferentially for a first distance until the deviation correction block 153 abuts against the first expansion piece in the retracted state. 2, preventing the bracket 15 from continuing to slide, that is, the first stage of sliding of the slider 14 is completed. At this time, the first limit block 151 and the second limit block 152 are both out of contact, the first expansion piece 2 and the second expansion piece 4 are unobstructed and can be turned over freely, and then tensile stress is applied to the soil nail pile body. Under the action of the first compression spring 3 and the surrounding soil, the first expansion piece 2 penetrates into the soil, and because the first expansion piece 2 has destroyed the soil during the penetration of the soil, the second expansion piece 4 is turned outward under the action of the second compression spring 41 and can be penetrated into the soil destroyed by the first expansion piece 2, until the first expansion piece 2 and the second expansion piece 4 are both close to the limit pressure plate 1, that is, the combination of the first expansion piece 2 and the second expansion piece 4 in the open state can improve the strength of the structure penetrated into the soil, thereby improving the pull-out resistance of the soil nail.

[0055] After the first expansion piece 2 and the second expansion piece 4 are both close to the limit pressure plate 1, the traction rope 30 is pulled axially along the soil nail rod body 10 again to drive the slider 14 to slide circumferentially along the soil nail rod body 10 for a second distance, so as to drive the correction block 153 to move, so that the correction block 153 is against the wide surface of the first expansion piece 2, thereby improving the fixing effect on the first expansion piece 2, thereby reducing the occurrence of the first expansion piece 2 breaking due to excessive pulling force.

[0056] And, if Figure 5 , Figure 7 As shown, a curved rod 154 is fixed to the portion of the bracket 15 located at the peripheral position of the limiting pressure plate 1, and the center of curvature of the curved rod 154 is located at the axis of the soil nail rod body 10. A reinforcement ring 16 arranged for the position of the first expansion piece 2 is fixed to the peripheral surface of the limiting pressure plate 1, and the axis of the reinforcement ring 16 coincides with the moving path of the curved rod 154; the relatively wide surfaces of the first expansion piece 2 and the second expansion piece 4 are fixed with a limiting ring sleeve 23 for the curved rod 154 to pass through, and when the first expansion piece 2 and the second expansion piece 4 are abutted against the limiting pressure plate 1, the limiting ring sleeve 23 is symmetrically arranged with the reinforcement ring 16 as the center.

[0057] When the slider 14 slides circumferentially along the soil nail rod body 10 for a second distance, the arc rod 154 is simultaneously inserted into the limiting ring sleeve 23 on the reinforcement ring 16, the first expansion piece 2 and the second expansion piece 4, that is, the limiting pressure plate 1, the first expansion piece 2 and the second expansion piece 4 in the open state are simultaneously limited and reinforced to be connected, so that the three become one, so as to improve the structural strength of the expansion reinforcement assembly 20, thereby further improving the pull-out resistance of the soil nail.

[0058] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. Single-stage and multi-stage tension expansion soil nails, characterized by: It comprises a soil nail rod body (10), an expansion and reinforcement component (20) arranged on the soil nail rod body (10), and a traction rope (30); the expansion and reinforcement component (20) comprises a limit pressure plate (1), a first expansion piece (2), an elastic member, a sleeve (11) sleeved and fixed on the soil nail rod body (10), and a second expansion piece (4) arranged at a position corresponding to the first expansion piece (2); The limit pressure plate (1) is fixedly arranged on the soil nail rod body (10); one side of the first expansion piece (2) is hingedly connected to the limit pressure plate (1); the wide surface of the first expansion piece (2) is projected along the axial direction of the soil nail rod body (10) on the surface of the limit pressure plate (1); the elastic member is used to force the free end of the first expansion piece (2) to turn away from the axis of the soil nail rod body (10) and along the insertion direction of the soil nail rod body (10), and the limit pressure plate (1) blocks the turning path of the first expansion piece (2); When the first expansion piece (2) abuts against the limit pressure plate (1), the radial distance between the free end of the first expansion piece (2) and the axis of the soil nail rod (10) is greater than the radial distance between the edge of the limit pressure plate (1) and the axis of the soil nail rod (10); the free end of the first expansion piece (2) is bent outwardly in a direction away from the axis of the soil nail rod (10) to form a sharp portion (21), and the thickness of the sharp portion (21) gradually increases in a direction toward the hinge end of the first expansion piece (2); the sleeve (11) is connected to a slider (14) in a circumferential sliding manner, and the slider (14) A first support rod (141) is provided for the traction rope (30) to pass around, and when the traction rope (30) is tightened along the axial direction of the soil nail rod body (10), the slider (14) is driven to slide; the slider (14) is fixed with a bracket (15), and the bracket (15) is fixed with a first limit block (151), and the sliding path of the first limit block (151) interferes with the turning path of the first expansion piece (2); when the first limit block (151) abuts against the wide surface of the first expansion piece (2) away from the soil nail rod body (10), the first expansion piece (2) is turned along the The axial projection of the soil nail rod body (10) is completely located on the surface of the limit pressure plate (1); one side of the second expansion piece (4) is hingedly connected to the surface of the limit pressure plate (1) facing away from the first expansion piece (2); a second compression spring (41) is provided between the second expansion piece (4) and the sleeve (11); the second compression spring (41) is used to force the free end of the second expansion piece (4) to flip in a direction away from the axis of the soil nail rod body (10) and toward the limit pressure plate (1); the limit pressure plate (1) blocks the flipping path of the second expansion piece (4); the bracket (15) A second limit block (152) is fixed, and the sliding path of the second limit block (152) interferes with the turning path of the second expansion piece (4); when the second limit block (152) abuts against the wide surface of the second expansion piece (4) away from the soil nail rod body (10), the projection of the second expansion piece (4) along the axial direction of the soil nail rod body (10) is completely located on the surface of the limit pressure plate (1); the bracket (15) is fixed with a correction block (153), and the shortest distance between the correction block (153) and the limit pressure plate (1) is equal to the thickness of the first expansion piece (2).

2. The single-stage and multi-stage tension expansion soil nail according to claim 1 is characterized in that: The first expansion pieces (2) are provided in plurality, and the first expansion pieces (2) are evenly arranged around the circumference of the soil nail rod body (10).

3. The single-stage and multi-stage tension expansion soil nail according to claim 1 is characterized in that: A hook ring is provided on the wide surface of the first expansion piece (2) facing away from the limiting pressure plate (1), and the elastic member is a first compression spring (3), one end of the first compression spring (3) is connected to the sleeve (11), and the other end of the first compression spring (3) is connected to the hook ring.

4. The single-stage and multi-stage tension-expandable soil nail according to claim 1, characterized in that: The bracket (15) is fixed with an arc rod (154) located on the outer peripheral side of the limit pressure plate (1), and the curvature center of the arc rod (154) is located at the axis of the soil nail rod body (10). The wide surfaces of the first expansion piece (2) and the second expansion piece (4) are fixed with a limit ring sleeve (23) for the arc rod (154) to pass through; when the first expansion piece (2) and the second expansion piece (4) are in contact with the limit pressure plate (1), the axis of the limit ring sleeve (23) thereon coincides with the moving path of the arc rod (154).

5. The single-stage and multi-stage tension-expandable soil nail according to claim 4, characterized in that: A reinforcement ring (16) is fixed to the circumferential surface of the position-limiting pressure plate (1), and the axis of the reinforcement ring (16) coincides with the moving path of the arc-shaped rod (154).

6. The single-stage and multi-stage tension-expandable soil nail according to claim 1, characterized in that: A resistance-enhancing strip (22) is protrudingly configured on a surface of the sharp portion (21) that faces away from the position-limiting pressure-bearing plate (1).

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