A displacement-adaptive shear-resistant anchor

Abstract

The utility model relates to a kind of displacement adaptive shear-resistant anchor rod, including first prestressed threaded rod body, elastic rod body, second prestressed threaded rod body, first adaptive sleeve and second adaptive sleeve, the first connection of first adaptive sleeve and the first connection of second adaptive sleeve are connected with the both ends of elastic rod body respectively, first prestressed threaded rod body is connected in the second connection of first adaptive sleeve, second prestressed threaded rod body is connected in the second connection of second adaptive sleeve;The first prestressed threaded rod body constitutes grouting anchoring section, the elastic rod body constitutes adaptive section, the second prestressed threaded rod body constitutes free section.The utility model is combined different anchor rod body by adaptive sleeve, and it is convenient to install, effectively applicable to soil continuous deformation condition and step deformation condition, can provide higher working resistance under the side slope large shear displacement, effectively solve the problem that existing supporting method cannot keep long-term stability of side slope.

Description

Technical Field

[0001] This utility model relates to the field of geotechnical engineering support, specifically to a displacement-adaptive anti-shear anchor, which is particularly suitable for slope engineering affected by long-term step deformation. Background Technology

[0002] Slope instability is a common engineering challenge in highway construction in hilly areas. Anchor bolts, a frequently used method for slope reinforcement, have evolved from non-prestressed to prestressed, and from structural to material-based anchors, strengthening the integrity of the soil and rock and fully utilizing their inherent strength. When there are important structures near the top of the slope, significant deformation of the support system is generally not permitted. In such cases, anchor bolts are often used to apply prestress within the soil or rock mass, increasing the friction and adhesion between the anchor bolt and the soil or rock, thereby enhancing the slope's resistance to sliding.

[0003] Currently, although prestressed anchor technology has been widely used in reinforcement projects, most existing engineering specifications and standards focus on tensile performance considerations and lack sufficient consideration of the shear joint effect of deep soil and soil-rock interface. This results in insufficient shear resistance of existing anchor reinforcement systems in the face of large deformations caused by complex ground stress and extreme weather conditions such as heavy rainfall. Summary of the Invention

[0004] The technical problem this invention aims to solve is to provide a displacement-adaptive anti-shear anchor that offers continuous working resistance and ensures reliable anchoring during the later stages of large shear deformation on slopes. It possesses the ability to co-deform with the rock mass and is effectively applicable to both continuous and step-deformation conditions, providing higher working resistance under large shear displacement on slopes. Its adaptive section allows for certain shear and tensile deformation under complex geostress and large slope deformation, while the prestressed threaded rod in the grouted anchoring section provides sufficient anchoring force to prevent premature failure of the anchor support system.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A displacement-adaptive shear anchor bolt includes a first prestressed threaded rod body, an elastic rod body, a second prestressed threaded rod body, a first adaptive sleeve, and a second adaptive sleeve. A first connecting portion of the first adaptive sleeve and a first connecting portion of the second adaptive sleeve are respectively connected to both ends of the elastic rod body. The first prestressed threaded rod body is connected to the second connecting portion of the first adaptive sleeve, and the second prestressed threaded rod body is connected to the second connecting portion of the second adaptive sleeve. The first prestressed threaded rod body constitutes a grouting anchoring section, the elastic rod body constitutes an adaptive section, and the second prestressed threaded rod body constitutes a free section. The first and second adaptive sleeves have identical structures, each including two connecting sleeves and a spherical joint. One end of each connecting sleeve is hinged to the spherical joint, and the other ends of each connecting sleeve are the first connecting portion and the second connecting portion, respectively. The hinge axes of the two connecting sleeves are orthogonal to the spherical joint.

[0006] Compared to traditional anchor bolts, the anchor bolt provided by this invention exhibits higher ductility and shear resistance when facing shear forces, effectively absorbing external stress and continuing to provide high working resistance even under severe deformation, significantly improving the stability of slope reinforcement. This invention analyzes existing anchor bolt support requirements and, based on the structural form of traditional anchor bolts, designs a composite anchor bolt body with an adaptive section through hinged connections between the bolt bodies. This not only possesses the ability to deform with the rock mass but also provides continuous working resistance in the later stages of large shear deformation on the slope, ensuring reliable anchoring performance.

[0007] An anchor plate and a preload nut are provided at the outer end of the second prestressed threaded rod.

[0008] The connecting sleeve is threadedly connected to the first prestressed threaded rod, the elastic rod, and the second prestressed threaded rod.

[0009] The elastic rod is an anchor rod made of plain round steel. The strength of the rod is not lower than the strength of the prestressed anchor rod specified in the slope engineering code, and the elongation after fracture is greater than 50%.

[0010] The connecting sleeve is provided with an ear plate, which is matched with a ball joint through a round hole on the ear plate.

[0011] The ball joint is provided with four positioning pins, which are located in the round holes on the ear plate.

[0012] The displacement-adaptive anti-shear anchor proposed in this utility model has the following functions: by combining different anchor bodies, it can meet the requirements of different anchoring depths while achieving economic benefits; the grouting anchoring section is a prestressed threaded rod, which, after being combined with stable rock or soil layers, can ensure sufficient anchoring force and limit large slope deformation; the various sections on the anchor body are connected by an adaptive sleeve through a hinge, which can convert the shear stress generated by the slope along the sliding direction into the axial force of the elastic rod, giving full play to the tensile strength and deformation capacity of the elastic rod, and can also distribute stress more evenly by yielding deformation, reducing the loss of prestress due to shear disturbance. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a displacement-adaptive shear anchor. Figure 2 A schematic diagram of an adaptive sleeve; Figure 3 This is a schematic diagram of a ball joint in an adaptive sleeve; Explanation of reference numerals in the attached figures: 1- Grouting anchorage section; 2- Adaptive section; 3- Free section; 4- External anchorage section; 5- First prestressed threaded rod; 6- Elastic rod; 7- Second prestressed threaded rod; 8- First adaptive sleeve; 9- Second adaptive sleeve; 10- Anchor plate; 11- Pre-tightening nut. Detailed Implementation

[0014] To make the technical features and advantages of this utility model clearer, a further detailed description will be provided in conjunction with the accompanying drawings.

[0015] A displacement-adaptive shear-resistant anchor, such as Figure 1 As shown, it consists of a first prestressed threaded rod 5, an elastic rod 6, a second prestressed threaded rod 7, a first adaptive sleeve 8, a second adaptive sleeve 9, an anchor plate 10, and a preload nut 11.

[0016] The displacement-adaptive anti-shear anchor provided by this utility model is generally divided into a grouting anchorage section 1, an adaptive section 2, a free section 3, and an external anchorage section 4 along its length. The first prestressed threaded rod 5 constitutes the grouting anchorage section 1. After the first prestressed threaded rod 5 is combined with stable rock or soil layers, it can ensure sufficient anchoring force and limit large slope deformation. The elastic rod 6 constitutes the adaptive section 2. The adaptive section 2 is hinged to the grouting anchorage section 1 through a first adaptive sleeve 8, and to the free section 3 through a second adaptive sleeve 9. This can convert the shear stress generated along the sliding direction of the slope into the axial force of the elastic rod, fully utilizing the tensile strength and deformation capacity of the elastic rod. Furthermore, by allowing deformation, the stress can be distributed more evenly, reducing the loss of prestress due to shear disturbance. An anchor plate 10 and a pre-tightening nut 11 are provided on the second prestressed threaded rod 7. The part of the second prestressed threaded rod 7 located inside the anchor plate 10 constitutes a free section, and the part of the second prestressed threaded rod 7 located outside the anchor plate 10 constitutes an outer anchoring section 4. The second prestressed threaded rod 7 is used to apply the prestress required by the slope engineering specifications.

[0017] Elastic rod 6 is a rod that can maintain continuous working resistance even after significant deformation. Elastic rod 6 is an anchor rod made of plain round steel, with a rod strength not lower than the prestressed anchor rod strength specified in the slope engineering code, and a post-fracture elongation greater than 50%.

[0018] The installation process for a displacement-adaptive shear anchor is as follows: 1. Determine the drilling depth and possible slope sliding surface location based on the site survey, and ensure that the grouting anchor section is installed on stable rock or soil layers, and the adaptive section is installed on unstable layers; 2. Design the length of each section of the anchor bolt according to the requirements of the slope engineering specifications; 3. The adaptive sleeve is sequentially fitted into the pre-processed first prestressed threaded rod 5, elastic rod 6, and second prestressed threaded rod 7 to form an adaptive anchor rod body; 4. After the PVC pipes are installed in the free section and the adaptive section, the adaptive anchor body is pushed into the borehole to the bottom and grouting is performed; 5. After the grout has solidified and reached the allowable tensile strength, install the anchor plates and pre-tightening nuts in sequence, and apply the prestress to the design value using on-site tensioning equipment; 6. After the anchor bolts and grid beams are constructed, an integral load-bearing structure is formed. After all tests (including slope deformation tests) are qualified, the concrete pad is roughened, the extra-long part of the outer anchor bolt body is cut off, and finally the anchor head is sealed with C30 concrete to protect it.

Claims

1. A displacement-adaptive shear-resistant anchor bolt, characterized in that: The system includes a first prestressed threaded rod (5), an elastic rod (6), a second prestressed threaded rod (7), a first adaptive sleeve (8), and a second adaptive sleeve (9). The first connecting part of the first adaptive sleeve (8) and the first connecting part of the second adaptive sleeve (9) are respectively connected to the two ends of the elastic rod (6). The first prestressed threaded rod (5) is connected to the second connecting part of the first adaptive sleeve (8), and the second prestressed threaded rod (7) is connected to the second connecting part of the second adaptive sleeve (9). The first prestressed threaded rod constitutes a grouting anchoring section, the elastic rod constitutes an adaptive section, and the second prestressed threaded rod constitutes a free section. The first adaptive sleeve (8) and the second adaptive sleeve (9) have the same structure, each including two connecting sleeves and a spherical joint. One end of the two connecting sleeves is hinged to the spherical joint, and the other end of the two connecting sleeves is the first connecting part and the second connecting part, respectively. The hinge axis of the two connecting sleeves is orthogonal to the spherical joint.

2. The displacement-adaptive shear anchor bolt according to claim 1, characterized in that: An anchor plate (10) and a preload nut (11) are provided at the outer end of the second prestressed threaded rod (7).

3. The displacement-adaptive shear anchor bolt according to claim 1, characterized in that: The connecting sleeve is threadedly connected to the first prestressed threaded rod, the elastic rod, and the second prestressed threaded rod.

4. The displacement-adaptive shear anchor bolt according to claim 1, characterized in that, The elastic rod (6) is an anchor rod made of plain round steel. The strength of the rod is not lower than the strength of the prestressed anchor rod specified in the slope engineering code, and the elongation after fracture is greater than 50%.

5. The displacement-adaptive shear anchor bolt according to claim 1, characterized in that, The connecting sleeve is provided with an ear plate, which is matched with a ball joint (82) through a round hole on the ear plate.

6. The displacement-adaptive shear anchor bolt according to claim 5, characterized in that, The ball joint (82) is provided with four positioning pins, which are located in the round holes on the ear plate respectively.

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