Multi-point frictional anti-slide anchor cable and installation method thereof
By using a multi-point friction anti-slip anchor cable design, the anchor cable body forms a stable structure with the rock and soil mass, directly bearing the sliding force of the landslide, solving the problems of high cost and high risk of traditional support methods, and achieving low-cost and high-efficiency slope support effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTHWEAT UNIV OF SCI & TECH
- Filing Date
- 2023-08-17
- Publication Date
- 2026-06-23
AI Technical Summary
Traditional slope protection methods require a large number of rigid retaining structures, resulting in high construction costs, large engineering workload, and significant disturbance to the slope. The risk of anchor cable failure in contact with the structure is high, making it difficult to effectively prevent deformation and erosion of the soil and rock.
Multi-point friction anti-slip anchor cables are adopted. The anchor cable body is installed at an angle in the slope. The anchoring section is fixed to the stable bedrock at the bottom of the sliding bed. Multiple friction blocks are arranged at equal intervals on the free section. Friction contact is formed through sealing capsules and grout-stopping components. The anchor head and the anti-slip block are fixed on the slope surface, achieving an anti-slip effect without the need for rigid support structures.
To reduce construction costs and workload, improve safety, the anchor cable directly bears the sliding force of the sliding body through the interaction of the friction block and the sliding body, resulting in good anti-sliding effect. The deep friction block still plays a role, reducing disturbance to the rock and soil mass and increasing the support range.
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Figure CN116905482B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of slope protection technology, specifically to a multi-point friction anti-slip anchor cable and its installation method. Background Technology
[0002] A slope consists of a sliding bed and a sliding mass; the contact surface between the sliding mass and the sliding bed is the slope slip surface. For example... Figure 1 As shown, in traditional slope protection engineering, anchor cables are often combined with anti-slide piles, pile-slab walls, lattice beams, pile banks, retaining walls, and other support structures to form a reasonably stressed anti-slide structure. In this case, the anchor cable can be divided into an anchoring section, a free section, and an anchor head according to its function. The anchoring section is fixed in the sliding bed, and the tension of the anchor cable acts on the pile body, wall, beam, and other structures. The role of the anchor cable here is equivalent to optimizing the internal force distribution of the pile, wall, and other support structures. The sliding force of the sliding body is not directly borne by the anchor cable, but is first transmitted to the support structure and then transmitted to the anchor cable strand itself through the anchor head. Therefore, existing slope protection engineering requires not only the design and construction of the anchoring structure, but also the design and construction of the support structure.
[0003] Large-scale slopes with overburden on bedrock surfaces—slopes with a significant spatial span—can be simplified into an infinite slope model in terms of their mechanical properties. For large-scale slopes with overburden, traditional support methods require a certain number and size of support structures to achieve effective support. Furthermore, the design of anchor cables and retaining structures necessitates significant consideration, leading to high construction costs. Traditional support methods also involve pile hole excavation, retaining wall ballast loading, and backfilling, further disturbing the already unstable slope. This results in a large workload and high risk. Moreover, deformation and soil loss are common phenomena at the slope's fracture surface due to natural or human disturbance. When the contact force between the anchor cables and the structure fails due to soil deformation, the anchoring force of the anchor cables fails, potentially damaging the structure and ultimately causing slope support failure. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-point friction anti-sliding anchor cable and its installation method. It can achieve excellent anti-sliding performance of slopes without the need for rigid support structures, change the spatial morphology of the slope sliding surface, give full play to the self-supporting capacity of the rock and soil, and form a more stable structure through the interaction between the anchor cable and the rock and soil. The overall structure is stable, and the construction safety can be improved while reducing the amount of engineering and construction costs.
[0005] The objective of this invention is achieved through the following technical solution:
[0006] A multi-point friction anti-slip anchor cable includes an anchor cable body, which includes an anchoring section and a free section connected to each other. The anchor cable body is installed obliquely in the slope. The anchoring section is anchored in the stable bedrock at the bottom of the sliding bed of the slope. The free section is provided with a plurality of friction blocks arranged at equal intervals, and the friction blocks are in frictional contact with the sliding body of the slope.
[0007] Furthermore, the free section is provided with multiple grout-stopping components arranged at equal intervals. Each grout-stopping component includes two grout-stopping plugs arranged opposite each other. Each grout-stopping plug includes a limiting plate and a sealing capsule. The limiting plate is fixed to the steel strand in the anchor cable body. The two sealing capsules in the grout-stopping component are located between the two limiting plates and are respectively bonded to the two limiting plates. The sealing capsules are filled with a liquid with a high compression modulus. The steel strand between the two sealing capsules is supported by a bearing bracket. The two sealing capsules form a friction block that is fixedly connected to the anchor cable body by grouting.
[0008] Furthermore, the anchor cable body also includes an anchor head, which is located on the slope surface. The slope surface is provided with an anti-blocking block corresponding to the anchor head. The anchor head includes a bearing platform, a fixing clip, a fixing cap, and a hollow fastening bolt. The steel strand in the anchor cable body passes through the anti-blocking block and is fixedly connected to it. The bearing platform is located on the side of the anti-blocking block away from the friction section and abuts against the anti-blocking block. The steel strand in the anchor cable body passes through the bearing platform and is clamped on the bearing platform by the fixing clip. A fixing cap is provided on the bearing platform, and a hollow fastening bolt is provided on the fixing cap to press the fixing clip onto the bearing platform. The steel strand in the anchor cable body passes through the hollow fastening bolt.
[0009] Based on the above structure, the present invention also provides a method for installing a multi-point friction anti-slip anchor cable, which includes the following steps:
[0010] The anchor cable body, excluding the anchor head, undergoes preliminary assembly, and grouting pipes are slidably inserted into the anchor cable body. The elevation angle of the anchor cable body during installation is set, and the effective support range of a single anchor cable body is calculated using the rigid body limit equilibrium method. Based on the effective support range of a single anchor cable body, the horizontal installation spacing between two adjacent rows of anchor cables is determined. The anchor points on the slope surface corresponding to the anchor cable body are determined based on the horizontal installation spacing between the two adjacent rows of anchor cables. Then, according to the set elevation angle, the anchor points are drilled from bottom to top using a casing drill. Extend the inclined anchor cable hole to the bottom of the slide bed to stabilize the bedrock; remove the drill rod and drill bit of the casing drill and leave the casing drill casing as the hole wall support for the inclined anchor cable hole, and clean the hole wall of the inclined anchor cable hole; put the preliminarily assembled anchor cable body into the inclined anchor cable hole along the casing, and then anchor the anchor section into the slide bed by grouting through the grouting pipe; after anchoring the anchor section, grout is injected through the grouting pipe from the inside to the outside to form friction blocks at multiple grouting components; after all friction blocks are grouted, pull out the grouting pipe and casing, and then install the anchor head to complete the overall installation of the anchor cable body.
[0011] Furthermore, the effective support range of a single anchor cable body is used as the horizontal installation spacing between two adjacent rows of anchor cable bodies.
[0012] Furthermore, let the angle of inclination of the anchor cable body during installation be... ,but ,in , In the formula The equivalent friction angle of the sliding surface. In the formula, c and The Mohr strength parameters of the slope slip surface are given. The weight of the sliding body. The vertical thickness of the sliding body. It is the angle between the slope slip surface and the horizontal plane.
[0013] Furthermore, according to the rigid body limit equilibrium method, for two adjacent anchor cable bodies, the corresponding anchor points on the slope surface are marked as B and D, respectively. The intersection point of the lower anchor cable body with the slope slip surface is marked as A. Let the horizontal projection length of the distance between A and B be denoted as... Let the horizontal projection length of the distance between A and D be . The effective support range of a single anchor cable body is .
[0014] Furthermore, In the formula The vertical thickness of the sliding body 10 is given. The angle between the slope slip surface and the horizontal plane. The tilt angle during anchor cable installation.
[0015] Furthermore, let B′ be the horizontal projection of anchor point B onto the slope slip surface, A′ be the vertical projection of anchor point A onto the slope surface, D′ be the horizontal projection of anchor point D onto the slope slip surface, and D″ be the vertical projection of anchor point D onto the slope slip surface. Then... In the formula, For safety reasons, Let be the volume of the sliding body within the triangle formed by vertices D, D′, and D″ under the action width of a single anchor cable. Let be the volume of the sliding body within the quadrilateral area with vertices A, A′, D, and D″ under the action width of a single anchor cable. Let be the volume of the sliding body within the quadrilateral region with vertices A, A′, B, and B′ under the action width of a single anchor cable. The weight of the sliding body. The body force generated by horizontal seismic acceleration. This refers to the seepage force generated by groundwater seeping downwards along the slope. and These are the cohesive forces within the slope sliding surface and the sliding body, respectively. and These are the friction angles of the slope sliding surface and the interior of the sliding body, respectively. This refers to the effective width of a single anchor cable.
[0016] Furthermore, when forming friction blocks through grouting, the casing of the casing drill is pulled outward from the inside to expose multiple grout-stopping components in sequence in the inclined anchor cable holes located at the sliding body. After a certain grout-stopping component is exposed, the grouting pipe is pulled outward so that the grouting port of the grouting pipe is located at the grout-stopping component. Then, grout is injected through the grouting pipe to seal the inclined anchor cable hole with the sealing capsule of the grout-stopping component. Grouting continues until the grout completely fills and expands the inclined anchor cable hole at the grout-stopping component. After the grout solidifies, a friction block is formed.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] 1. Compared with traditional slope engineering using anchor cable support, the multi-point friction anti-slide anchor cable of the present invention directly bears the sliding force generated by the sliding body through the friction block of the anchor cable body itself inside the sliding body. It does not require rigid support structures such as anti-slide piles, lattice beams, and retaining walls, nor does it require prestressing at the anchor head. The structure and design principle are simple, the construction cost is low, and it can be widely promoted and used.
[0019] 2. This invention helps improve the safety and quality of anti-slide engineering. Since it eliminates the need for anchor heads and other rigid support structures to be combined with the outside of the sliding body, it avoids the risk of failure of the contact force between the rigid support structure and the sliding body due to soil deformation (e.g., in anchor cable + frame beam anti-slide structures, where the frame beam is located on the slope surface, long-term rainfall can lead to soil erosion causing the frame beam to become suspended between the frame beam and the sliding body, significantly reducing the support effect). Furthermore, because the multi-point friction anti-slide anchor cable of this invention interacts with the sliding body through friction blocks, the tensile stress of the anchor cable is passively generated. Therefore, even if the sliding body undergoes large sliding deformation relative to the anchor cable, the anti-slide effect will continue as long as the friction blocks remain in contact with the sliding body.
[0020] 3. The slope treatment effect of the present invention is better: For large-scale slopes with large foundations, traditional support methods require a certain number and size of support structures to achieve good results, which often leads to extremely high engineering costs. However, reducing engineering costs will inevitably reduce the structural safety factor and affect the protection effect. The slope reinforced by the multi-point friction anti-slide anchor cable of the present invention has a large range and depth of action due to the inclined installation of the anchor cables. It can not only generate considerable anti-slide force deep inside the sliding body, but also fully utilize the geometric characteristics of the structure to give full play to the material strength characteristics of the rock and soil in the sliding body relative to the sliding surface. In other words, the slope reinforced by the multi-point friction anti-slide anchor cable is essentially the anti-slide force generated by the interaction between the rock and soil and the anchor cables, which fully utilizes the bearing capacity of the rock and soil itself. It is not only economical, but also effective.
[0021] 4. The key to traditional anchor cable support lies in the connection quality of the anchor head, which ensures that the prestress of the anchor cable can be fully utilized. In contrast, the anchor head of the multi-point friction anti-slip anchor cable of this invention does not play the same role. It mainly plays an anti-slip role on the slope surface and provides constraint for the outer section of the steel cable bundle structure of the anchor cable. Therefore, theoretically, the tensile force borne by the anchor cable between the anchor head and the friction block will be at its minimum. Even if the slope deforms or soil erosion occurs, and the anchor head and the anti-slip block lose direct anti-slip force with the sliding body, there is no need to worry about the anti-slip effect of the anchor cable. The friction block deep inside still plays a role, and the anti-slip block connected to the anchor head is suspended and presses down on the slope surface, playing a certain ballast role.
[0022] 5. In existing slope or landslide engineering, anchor cables often provide tension to the relevant anti-sliding structure through their large tensile force, and the anti-sliding structure then resists the sliding force of the landslide. Alternatively, anchor rods directly hold the deformation of the relevant rock and soil mass to prevent damage. However, this invention not only directly resists the sliding force of the landslide through the anchor cable itself, but also changes the potential sliding failure surface and increases the support range. Therefore, this invention differs from the traditional role of anchor cables in slopes and landslides in principle. Attached Figure Description
[0023] Figure 1 A schematic diagram of existing traditional anchor cable installation;
[0024] Figure 2 This is a schematic diagram of the support provided by the multi-point friction anti-slip anchor cable in this invention;
[0025] Figure 3 This is a schematic diagram of the overall structure of the multi-point friction anti-slip anchor cable in this invention;
[0026] Figure 4 This is a schematic diagram of the anchoring section in this invention;
[0027] Figure 5This is a schematic diagram of the friction block segment in this invention;
[0028] Figure 6 This is a schematic diagram of the structure of the slurry plug of the present invention;
[0029] Figure 7 This is a schematic diagram of the free section and the anchoring section in this invention;
[0030] Figure 8 This is a schematic diagram illustrating the working principle of the slurry plug termination of the present invention;
[0031] Figure 9 This is a schematic diagram of the installation process of the multi-point friction anti-slip anchor cable in this invention;
[0032] Figure 10 This is a schematic diagram of an infinite slope model after the installation of the multi-point friction anti-slip anchor cable in this invention.
[0033] In the diagram: 1. Grouting pipe; 2. Steel strand; 3. Anchoring section; 31. Wire ring; 32. Hoop ring; 33. Guide cap; 4. Free section; 41. Protective sleeve; 42. Centering bracket; 51. Grout stop plug; 511. Limiting plate; 512. Sealing capsule; 52. Bearing bracket; 6. Anchor head; 61. Anti-slip block; 62. Bearing platform; 63. Fixing clamp; 64. Fixing cap; 65. Hollow fastening bolt; 7. Friction block; 8. Pipe drill; 81. Sleeve; 9. Inclined anchor cable hole; 10. Sliding body; 11. Slide bed. Detailed Implementation
[0034] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.
[0035] like Figure 3-7 As shown, a multi-point friction anti-slip anchor cable is used in slope protection engineering. It includes an anchor cable body comprising interconnected anchoring sections 3 and free sections 4. The anchor cable body has the same structure as existing anchor cables, consisting of multiple steel strands 2. The steel strands 2 can be made of tensile materials such as steel strands, steel cables, or steel wires. Since anchor cables are typically fixed to the slope via grouting, a grouting pipe 1 can be slidably inserted into the anchor cable body. After insertion into the grouting pipe 1, the multiple steel strands 2 surround the grouting pipe 1.
[0036] like Figure 4As shown, anchoring section 3 is an anchoring structure found in conventional permanent anchor cables. It is anchored within the slide bed 11 of the slope via grouting, thus providing overall fixation for the anchor cable. Besides the steel strands 2, anchoring section 3 also includes a wire-supporting ring 31, a clamping ring 32, and a guide cap 33. Multiple wire-supporting rings 31 are arranged at equal intervals along the steel strands 2 within the anchor cable body. The steel strands 2 of anchoring section 3 are supported on the wire-supporting rings 31. The multiple strands 2 between adjacent wire-supporting rings 31 are tightened by the clamping rings 32. The guide cap 33 is fitted onto the end of anchoring section 3 furthest from the friction block 7. The grouting pipe 1 can slide through the wire-supporting rings 31 and the clamping rings 32. To ensure sufficient anchoring force for the entire anchor cable, the surface of the steel strands 2 in anchoring section 3 needs to be cleaned and rust-removed to facilitate adhesion to the anchoring agent and slide bed 11 after grouting.
[0037] In order to support the slope, multiple friction blocks 7 are arranged at equal intervals on the free section 4. The friction blocks 7 are in frictional contact with the sliding body 10 of the slope, thereby achieving the anti-sliding effect on the sliding body 10. Preferably, the distance between two adjacent friction blocks 7 is 3 to 6 m.
[0038] Specifically, such as Figure 5 , 6 As shown, the grout-stopping assembly includes two grout-stopping plugs 51 arranged opposite to each other. Each grout-stopping plug 51 includes a limiting plate 511 and a sealing capsule 512. The limiting plate 511 is fixedly connected to the multi-strand steel strands 2 in the anchor cable body. The two sealing capsules 512 in the grout-stopping assembly are located between the two limiting plates 511 and are respectively bonded to the two limiting plates 511. The sealing capsules 512 are filled with a liquid with a high compression modulus. A bearing bracket 52 is provided between the two sealing capsules 512. The multi-strand steel strands 2 between the two sealing capsules 512 are fixedly connected to the bearing bracket 52, thereby supporting the multi-strand steel strands 2 through the bearing bracket 52. A friction block 7 is formed between the two sealing capsules 512 through grouting and is fixedly connected to the steel strands 2. The grouting pipe 1 can slide through the limiting plate 511, the sealing capsules 512 and the bearing bracket 52.
[0039] Through the frictional contact between the aforementioned friction blocks and the sliding body, the interaction between the anchor cable and the soil and rock mass forms a more stable structure, which can change the spatial morphology of the slope sliding surface and give full play to the self-supporting capacity of the soil and rock mass.
[0040] like Figure 7As shown, the free section 4, excluding the grout-stopping assembly, is equipped with a protective sleeve 41 and a centering bracket 42. The protective sleeve 41 is fitted around the multi-strand steel strands 2 inside the anchor cable body. The multi-strand steel strands 2 inside the protective sleeve 41 are restrained by the centering bracket 42. The grouting pipe 1 can slide through the centering bracket 42. Preferably, the protective sleeve 41 can be made directly from a corrugated pipe, and the steel strands are further derusted. Multiple centering brackets 42 are provided, and the multiple centering brackets 42 are evenly distributed along the steel strands 2 at a distance of 1.5 to 2 m to prevent the multi-strand steel strands 2 from tangling with each other.
[0041] To further enhance the anti-sliding effect on the slope surface, such as Figure 7 As shown, the anchor cable body also includes an anchor head 6, which is located on the slope surface. The slope surface is provided with an anti-blocking block 61 corresponding to the anchor head 6. The anti-blocking block 61 is preferably a steel-concrete structure and is prefabricated on the slope surface at the anchor point corresponding to the anchor cable body. Specifically, the anchor head 6 includes a bearing platform 62, a fixing clip 63, a fixing cap 64, and a hollow fastening bolt 65. The steel strand 2 in the anchor cable body passes through the anti-slip block 61 and is fixedly connected to the anti-slip block 61. The bearing platform 62 is located on the side of the anti-slip block 61 away from the friction section and abuts against the anti-slip block 61. The steel strand 2 in the anchor cable body passes through the bearing platform 62 and is clamped on the bearing platform 62 by the fixing clip 63. The fixing cap 64 is fixed on the bearing platform 62, and the hollow fastening bolt 65 is threaded onto the fixing cap 64. The steel strand 2 passes through the hollow fastening bolt 65, and then the fixing clip 63 can be pressed onto the bearing platform 62 by tightening the hollow fastening bolt 65, thereby fixing and end-constraining the steel strand 2. The grouting pipe 1 can slide through the bearing platform 62 and the fixing cap 64.
[0042] Based on the aforementioned anchor cable structural characteristics, theoretically, the tensile force borne by the anchor cable from the anchor head to the outermost friction block of this invention will be at its minimum. The direct interaction between each friction block and the sliding body causes the tensile force borne by the anchor cable to gradually increase with depth. Therefore, even if slope deformation or soil erosion occurs, and the direct anti-sliding force between the anchor head, the anti-sliding block, and the sliding body is lost, there is no need to worry about the anti-sliding effect of the anchor cable, because the deeper friction blocks still function, and the anti-sliding block connected to the anchor head is suspended and presses down on the slope surface, providing a certain ballast effect.
[0043] In existing slope protection engineering, under certain circumstances, anchor cables are arranged in rows at intervals, and the corresponding anchor points on the slope surface are arranged in a quincunx pattern. Furthermore, based on the safety factor requirements of existing slope protection engineering, the spacing between rows of anchor cables needs to be designed. Based on this, if... Figure 9 As shown, the installation of the multi-point friction anti-slip anchor cable of the present invention includes the following installation steps:
[0044] The anchor cable body, except for the anchor head 6, is initially assembled, and the grouting pipe 1 is slidably inserted into the anchor cable body to prepare for installation.
[0045] Let the angle of inclination of the anchor cable body during installation be... Based on existing engineering technology conditions, the tilt angle during anchor cable installation should not be too large or too small, otherwise it will lead to poor project economics. Therefore, the tilt angle needs to be set before drilling and installing the anchor cable. Generally speaking, ,in , In the formula This is the equivalent friction angle of the sliding surface; while In the formula, c and These are the cohesion and friction angle of the slip surface, respectively (both cohesion and friction angle under saturation conditions are taken as effective strength values). The specific weight of the sliding body 10 is taken as the natural specific weight under natural conditions and the saturated specific weight under saturated conditions. The vertical thickness of the sliding body 10 is given. It is the angle between the slope slip surface and the horizontal plane.
[0046] After setting the installation tilt angle, the effective support range of a single anchor cable body can be calculated using the rigid body limit equilibrium method, so as to determine the horizontal installation spacing between two adjacent rows of anchor cables based on the effective support range of a single anchor cable body.
[0047] like Figure 10 As shown, for two adjacent anchor cable bodies, the corresponding anchor points on the slope surface are marked as B and D, respectively. The intersection of the lower anchor cable body and the slope slip surface is marked as A. Let the horizontal projection length of the distance between A and B be . Let the horizontal projection length of the distance between A and D be . The effective support range of a single anchor cable body is .
[0048] in,
[0049] In the formula, The vertical thickness of the sliding body 10 is given. The angle between the slope slip surface and the horizontal plane. The tilt angle during anchor cable installation.
[0050] Let B′ be the horizontal projection of anchor point B onto the slope slip surface, A′ be the vertical projection of anchor point A onto the slope surface, D′ be the horizontal projection of anchor point D onto the slope slip surface, and D″ be the vertical projection of anchor point D onto the slope slip surface.
[0051]
[0052] In the formula, The safety factor, which is related to the design operating conditions, is greater than 1. , and They are respectively Figure 10 The volume of the sliding body 10 within the three different polygonal ranges under the action width of a single anchor cable is equal to the area of the corresponding polygon multiplied by the action width of the single anchor cable. Let be the volume of the sliding body 10 within the triangle range with vertices D, D′, and D″ under the action width of a single anchor cable. Let be the volume of the sliding body 10 within the quadrilateral area with vertices A, A′, D, and D″ under the action width of a single anchor cable. Let be the volume of the sliding body 10 within the quadrilateral range with vertices A, A′, B, and B′ under the action width of a single anchor cable; The specific weight of the sliding body 10 (the specific weight under natural conditions is taken, and the specific weight under saturated conditions is taken). The body force generated by horizontal seismic acceleration. This refers to the seepage force generated by groundwater seeping downwards along the slope. The cohesion of the slope slip surface (the effective strength value is taken under saturation). The cohesive force inside the sliding body 10 (the effective strength value is taken under saturation). The friction angle of the slope sliding surface (taken as the effective strength value under saturation state). The friction angle inside the sliding body 10 (the effective strength value is taken under saturation conditions). The effective width of a single anchor cable (generally 0.5 times the vertical thickness of the sliding body 10, and not exceeding 1.5 times the vertical thickness of the sliding body 10).
[0053] Preferably, in this embodiment, the effective support range of a single anchor cable body is used as the horizontal installation spacing between two adjacent rows of anchor cable bodies. This ensures that the anchor cables are installed at the maximum horizontal installation spacing while maintaining the effective support range, thereby minimizing the use of anchor cables and saving construction costs.
[0054] After determining the installation spacing between the upper and lower rows, holes can be drilled from the anchor points on the sliding body 10 according to the set inclination angle. Since the sliding body 10 is mainly loose soil and prone to collapse, it is preferable to use a casing drill 8 to drill inclination anchor holes 9 extending from bottom to top to the bottom of the sliding bed 11 to stabilize the bedrock. After drilling, the drill rod and drill bit of the casing drill 8 are removed, leaving the casing 81 of the casing drill 8 as a hole wall support. The hole wall of the inclination anchor hole 9 is then cleaned, and the casing 81 of the casing drill 8 is used to prevent the inclination anchor hole 9 from collapsing.
[0055] After the construction of the inclined anchor cable hole 9 is completed, the preliminarily assembled anchor cable body is placed into the inclined anchor cable hole 9 along the casing 81 of the casing drill 8. Then, grouting is performed through the grouting pipe 1 to anchor the anchoring section 3 into the slide bed 11. When grouting the anchoring section 3, the casing 81 of the casing drill 8 is pulled outward to expose the anchoring section 3 in the inclined anchor cable hole 9 located at the slide bed 11. Then, the grouting pipe 1 is slowly and evenly pulled outward while grouting is performed until the grout completely fills the inclined anchor cable hole 9 located in the stable bedrock at the bottom of the slide bed 11. After the grout solidifies, the anchoring of the anchoring section 3 is completed.
[0056] After anchoring section 3 is anchored, grout is injected through grouting pipe 1 to form friction blocks 7 at multiple grout-stopping components sequentially from the inside out. Specifically, the casing 81 of the casing drill 8 is pulled outward from the inside to expose multiple grout-stopping components sequentially in the inclined anchor cable hole 9 located at the sliding body 10. After a certain grout-stopping component is exposed, the grouting pipe 1 is pulled outward so that the grouting port of the grouting pipe 1 is located at that grout-stopping component, and then grouting begins. Figure 8 As shown, during grouting, as the grout fills the inclined anchor cable hole 9, it squeezes the sealing capsules 512 at both ends of the friction section. The liquid inside the sealing capsules 512 is difficult to compress, and thus, due to axial pressure, it generates radial pressure and expands and deforms. This causes the liquid inside the sealing capsules 512 to squeeze the hole wall of the inclined anchor cable hole 9 and the internal pipelines of the anchor cable body, thereby sealing the inclined anchor cable hole 9 of the friction section. The limiting plate 511 prevents the sealing capsules 512 from moving along the steel strand during grouting. After the inclined anchor cable hole 9 is sealed, the grout cannot leak out of the friction section. As grouting continues, the grout will completely fill and expand the inclined anchor cable hole 9 at the grout-stopping assembly. After the grout solidifies, it forms the friction block 7 that frictionally contacts the sliding body 10.
[0057] After all friction block segments 5 are grouted, pull out the grouting pipe 1 and the casing 81 of the casing drill 8, and then install the anchor head 6 to complete the overall installation of the anchor cable body.
[0058] Based on the structure and installation method of the multi-point friction anti-slip anchor cable described above, when the installed multi-point friction anti-slip anchor cable deforms and slides, the friction block 7 passively generates an anti-slip force on the sliding body 10 due to frictional contact with the sliding body 10, thereby achieving an anti-slip effect on the sliding body 10 deep in the slope. The anchoring force received by the bearing platform 62 in the anchor head 6 is transmitted to the anchor cable body, thereby achieving a certain anti-slip effect on the sliding body 10 on the surface of the slope. Therefore, when the sliding body 10 deforms and slides, the sliding force of the multi-point friction anti-slip anchor cable of the present invention is directly borne by the anchor cable body itself, without the need for the anchor head 6 to be connected to an additional rigid support structure to bear the sliding force of the sliding body 10. Furthermore, through the inclined installation and the spacing of the friction block 7, the anti-slip force is effectively resisted. The multi-point friction anti-slip anchor cable of this invention provides multi-point anti-slip protection for the sliding body 10 while ensuring sufficient anti-slip range and depth. Even if the sliding body 10 undergoes significant sliding deformation relative to the anchor cable, the anchor cable will always play an anti-slip role as long as the friction block 7 remains in contact with the sliding body 10. Therefore, the multi-point friction anti-slip anchor cable of this invention has excellent anti-slip performance for slopes without the need for rigid support structures. It not only directly resists the sliding force of the sliding body through the anchor cable body, but also changes the potential sliding failure surface and increases the support range. This is different from the existing anchor cable structure combined with the anti-slip structure to generate tension on the sliding body. Moreover, the overall structure is simple, reliable, and has strong fault tolerance, making it suitable for various slope protection projects, especially for the prevention and control of large-scale slopes.
[0059] In addition, since the multi-point friction anti-slip anchor cable of the present invention does not require a rigid support structure during use, it eliminates the need for additional pile hole excavation, retaining wall ballast and backfilling for the rigid support structure. This not only reduces structural design and installation, but also reduces construction volume and cost. It also reduces human disturbance to the slope, thereby improving construction safety. Furthermore, it does not require prestressing of the anchor head 6 during installation; it is only necessary to ensure that the steel strand 2 is basically straight during installation.
[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for installing a multi-point friction anti-slip anchor cable, characterized in that: The multi-point friction anti-slip anchor cable includes an anchor cable body, which includes an anchoring section (3) and a free section (4) connected to each other. The anchor cable body is installed at an inverted angle in the slope. The anchoring section (3) is anchored in the stable bedrock at the bottom of the sliding bed (11) of the slope. The free section (4) is provided with multiple friction blocks (7) arranged at equal intervals. The friction blocks (7) are in frictional contact with the sliding body (10) of the slope. The free section (4) is provided with multiple grout-stopping components arranged at equal intervals. The anchor cable body also includes an anchor head (6), which is located on the slope surface of the slope. The installation steps for multi-point friction anti-slip anchor cables are as follows: The anchor cable body, except for the anchor head (6), is initially assembled, and the grouting pipe (1) is slidably inserted into the anchor cable body. Set the tilt angle of the anchor cable body during installation, then calculate the effective support range of a single anchor cable body according to the rigid body limit equilibrium method, and use the effective support range of a single anchor cable body as the horizontal installation distance between two adjacent rows of anchor cables. The anchor points on the slope surface of the anchor cable body are determined according to the horizontal installation spacing between the two adjacent rows of anchor cable bodies. Then, according to the set inclination angle, the inclination anchor cable hole (9) is drilled from bottom to top at the anchor point by the pipe drill (8) and extends to the bottom of the slide bed (11) to stabilize the bedrock. Remove the drill rod and drill bit of the casing drill (8) and leave the casing (81) of the casing drill (8) as a support for the hole wall of the inclined anchor cable hole (9), and clean the hole wall of the inclined anchor cable hole (9). The pre-assembled anchor cable body is placed into the inclined anchor cable hole (9) along the sleeve (81), and then the anchoring section (3) is anchored into the slide bed (11) by grouting through the grouting pipe (1). After anchoring the anchoring section (3), grout is injected through the grouting pipe (1) to form friction blocks (7) at multiple grout-stopping components from the inside out. After all friction blocks (7) are grouted, pull out the grouting pipe (1) and sleeve (81), and then install the anchor head (6) to complete the overall installation of the anchor cable body.
2. The installation method of the multi-point friction anti-slip anchor cable according to claim 1, characterized in that: The grout-stopping assembly includes two grout-stopping plugs (51) arranged opposite to each other. Each grout-stopping plug (51) includes a limiting plate (511) and a sealing capsule (512). The limiting plate (511) is fixed on the steel strand (2) in the anchor cable body. The two sealing capsules (512) in the grout-stopping assembly are located between the two limiting plates (511) and are respectively bonded to the two limiting plates (511). The sealing capsules (512) are filled with a liquid with a high compression modulus. The steel strand (2) between the two sealing capsules (512) is supported by a bearing bracket (52). The two sealing capsules (512) are grouted to form a friction block (7) that is fixedly connected to the anchor cable body.
3. The installation method of the multi-point friction anti-slip anchor cable according to claim 2, characterized in that: The slope surface is provided with anti-blocking blocks (61) corresponding to the anchor head (6). The anchor head (6) includes a bearing platform (62), a fixing clip (63), a fixing cap (64), and a hollow fastening bolt (65). The steel strand (2) in the anchor cable body passes through the anti-blocking block (61) and is fixedly connected to the anti-blocking block (61). The bearing platform (62) is located on the side of the anti-blocking block (61) away from the friction section and abuts against the anti-blocking block (61). The steel strand (2) in the anchor cable body passes through the bearing platform (62) and is clamped on the bearing platform (62) by the fixing clip (63). The bearing platform (62) is provided with a fixing cap (64). The fixing cap (64) is provided with a hollow fastening bolt (65) that presses the fixing clip (63) on the bearing platform (62). The steel strand (2) in the anchor cable body passes through the hollow fastening bolt (65).
4. The installation method of the multi-point friction anti-slip anchor cable according to claim 1, characterized in that: Let the angle of inclination of the anchor cable body during installation be... ,but ,in , In the formula The equivalent friction angle of the slope sliding surface. In the formula, c and The Mohr strength parameters of the slope slip surface are given. The weight of the sliding body (10) Let the vertical thickness of the sliding body (10) be , It is the angle between the slope slip surface and the horizontal plane.
5. The installation method of the multi-point friction anti-slip anchor cable according to claim 4, characterized in that: According to the rigid body limit equilibrium method, for two adjacent anchor cable bodies, the corresponding anchor points on the slope surface are marked as B and D, respectively. The intersection point of the lower anchor cable body with the slope slip surface is marked as A. Let the horizontal projection length of the distance between A and B be denoted as... Let the horizontal projection length of the distance between A and D be . The effective support range of a single anchor cable body is .
6. The installation method of the multi-point friction anti-slip anchor cable according to claim 5, characterized in that: In the formula denoted as the vertical thickness of the sliding body (10).
7. The installation method of the multi-point friction anti-slip anchor cable according to claim 6, characterized in that: Let B′ be the horizontal projection of anchor point B onto the slope slip surface, A′ be the vertical projection of anchor point A onto the slope surface, D′ be the horizontal projection of anchor point D onto the slope slip surface, and D″ be the vertical projection of anchor point D onto the slope slip surface. In the formula, For safety reasons, Let the volume of the sliding body (10) within the triangle range with vertices D, D′, and D″ under the action width of a single anchor cable be denoted as . Let the volume of the sliding body (10) within the quadrilateral range with vertices A, A′, D, and D″ be the volume under the action width of a single anchor cable. Let the volume of the sliding body (10) within the quadrilateral range with vertices A, A′, B, and B′ be the volume under the action width of a single anchor cable. The weight of the sliding body (10) The body force generated by horizontal seismic acceleration. This refers to the seepage force generated by groundwater seeping downwards along the slope. and These are the cohesive forces within the slope sliding surface and the sliding body (10), respectively. and These are the friction angles inside the slope sliding surface and the sliding body (10), respectively. This refers to the effective width of a single anchor cable.
8. The installation method of the multi-point friction anti-slip anchor cable according to claim 3, characterized in that: When forming a friction block (7) by grouting, the casing (81) of the casing drill (8) is pulled outward from the inside to expose multiple grout-stopping components in the inclined anchor cable hole (9) located at the sliding body (10) in sequence. After a certain grout-stopping component is exposed, the grouting pipe (1) is pulled outward so that the grouting port of the grouting pipe (1) is located at the grout-stopping component. Then, grouting is carried out through the grouting pipe (1) to seal the inclined anchor cable hole (9) with the sealing capsule (512) of the grout-stopping component. Then, grouting continues until the grout completely fills and expands the inclined anchor cable hole (9) at the grout-stopping component. After the grout solidifies, a friction block (7) is formed.