Pre-stressed anchor cable positioning structure and positioning method

Abstract

The invention discloses a pre-stressed anchor cable positioning structure and method, and the positioning structure comprises a mounting seat which is provided with a first end face and a second end face, and a clamping assembly which is arranged on the first end face and is provided with a clamping opening capable of providing clamping force; the positioning block is arranged in the clamping opening and used for enabling the positioning block to be arranged in the internal space in a suspended mode through the clamping assembly; wherein the tensioning section penetrates through the second end face, then extends into the inner space and is used for being connected with the positioning block, the tensioning section is configured with a tensioning force F < pre >, the clamping assembly is configured to apply a radial clamping force N to the positioning block, and the contact face of the positioning block and the clamping assembly has a static friction coefficient mu, and the requirement that the maximum static friction force mu * N applied to the positioning block by the clamping assembly is larger than the tensioning force F < pre > of the tensioning section is met. The technical problems that in the prior art, a pre-stressed anchor cable monitoring mode is insufficient in reliability and high in cost are solved.

Description

Technical Field

[0001] This invention relates to the field of anchor cable construction technology, specifically to a prestressed anchor cable positioning structure and positioning method. Background Technology

[0002] Prestressed anchor cable technology is widely used in geotechnical engineering, including slope protection, deep foundation pit support, dam stabilization, and geological disaster prevention. It applies active compressive stress to the supported structure by tensioning and anchoring steel strands in stable rock and soil, thereby significantly improving the stress state and stability of the structure. However, existing prestressed anchor cable technology faces several inherent defects during long-term service: 1. Poor long-term prestress retention: The prestress in the anchor cable will continuously decrease due to factors such as lock retraction, steel strand slack, creep of the anchoring section grout, and rheology of the surrounding rock and soil. This loss is hidden and difficult to detect visually, but it directly leads to a decrease in support effectiveness and may even cause engineering instability. 2. Difficulty in Effectively Monitoring and Early Warning of the Health Status of Support Structures: Currently, monitoring the health status of anchor cables mainly relies on two methods: one is periodic manual inspection, which cannot quantify prestress values ​​and is difficult to detect internal damage; the other is the installation of electronic sensors (such as vibrating wire sensors and fiber optic grating sensors), which, while enabling quantitative monitoring, suffers from high costs, requires continuous power supply, has significant long-term stability issues due to environmental influences, and is prone to failure in harsh engineering environments. Therefore, the industry urgently needs a long-term monitoring method that is moderately cost-effective, requires no external power supply, is stable and reliable, and can provide intuitive early warnings. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a prestressed anchor cable positioning structure and method, which solves the technical problems of insufficient reliability and high cost of existing prestressed anchor cable monitoring methods.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a prestressed anchor cable positioning structure, wherein the anchor cable includes an anchoring section, a free section, and a tensioning section, and the positioning structure includes:

[0005] The mounting base has a first end face and a second end face, and an internal space of the mounting base is formed between the first end face and the second end face.

[0006] A clamping assembly is disposed on the first end face and has a clamping opening that can provide clamping force;

[0007] A positioning block is disposed in the clamping opening, so that the positioning block is suspended in the internal space by the clamping assembly;

[0008] The tensioning section extends through the second end face and into the internal space to connect with the positioning block. The tensioning section is equipped with a tension force F.预 The clamping assembly is configured to apply a radial clamping force N to the positioning block, and the contact surface between the positioning block and the clamping assembly has a static friction coefficient μ, and the maximum static friction force μ·N applied by the clamping assembly to the positioning block is greater than the tension force F of the tensioning section. 预 .

[0009] Furthermore, the clamping assembly includes a positioning seat and a plurality of clamping blocks movably disposed on the positioning seat, each of the clamping blocks being movably connected to the positioning seat via a threaded rod.

[0010] Furthermore, the contact surface between the clamping block and the positioning block is provided with a copper-based powder metallurgy liner.

[0011] Furthermore, the inner wall of the second end face is a tapered surface that gradually tapers in the direction away from the first end face.

[0012] Furthermore, the tensioning section is provided with a positioning disk and a rotating disk at intervals away from the second end face, as well as multiple auxiliary lines disposed between the two, and the multiple auxiliary lines are inclinedly wrapped around the tensioning section.

[0013] Furthermore, the rotating disk can be movably positioned relative to the positioning disk to gradually tension the auxiliary line and move the positioning disk away from the rotating disk.

[0014] The present invention also provides a positioning method, including the prestressed anchor cable positioning structure described above. The positioning method includes the following steps: S1: the anchor cable is installed in the anchor hole, and the tensioned section at the end of the anchor cable is connected to the positioning block in the mounting seat and then fixed to the waist beam.

[0015] S2: Operate the clamping assembly to cause its multiple clamping blocks to apply clamping force to the positioning block;

[0016] S3: Apply prestress to the tensioning section of the anchor cable up to the design value F. 预 And complete the anchoring;

[0017] S4: Tensioning section maintains prestress F 预 In this state, adjust each clamping block synchronously to increase its clamping force on the positioning block until the following conditions are met:

[0018]

[0019] Where μ is the static friction coefficient between the contact surfaces of the positioning block and the clamping block, N i The clamping force applied to the i-th clamping block, where n is the total number of clamping blocks, ensures that the maximum static friction force generated is greater than the current tension force F. 预 ;

[0020] S5; Positioning discs and rotating discs are set at intervals in the tensioning section away from the fixed seat, and multiple auxiliary lines are inclinedly wrapped around the tensioning section;

[0021] S6: After construction is completed, observe whether the positioning block has shifted within the clamping opening.

[0022] Furthermore, in step S4, the clamping blocks are rotated synchronously by the motor to ensure that the clamping force N applied by each clamping block is constant. i Maintain consistency.

[0023] Furthermore, in step S6, the change in the length of the auxiliary line can be observed in the early stage of the disappearance of the prestress in the tensioning section. If the auxiliary line is gradually tightened by the rotating disk, the prestress in the tensioning section will gradually fail.

[0024] Compared with existing technologies, the present invention has the following advantages: The present invention connects to the prestressed anchor cable through a positioning structure, thereby reducing the invisible anchor cable tension (F). 预 The system transforms the prestressed anchor cable into a readily observable mechanical motion, allowing for early prediction of its safety status. It also provides an interference-resistant, long-lasting monitoring solution to replace electronic sensors. The entire device is constructed from metal mechanical components, requires no power supply, and is resistant to moisture, corrosion, lightning strikes, and electromagnetic interference, making it suitable for long-term monitoring in harsh conditions such as outdoor and underground environments. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the installation of the positioning structure in one embodiment of the present invention;

[0026] Figure 2 This is a partial structural diagram of the positioning structure in one embodiment of the present invention.

[0027] The reference numerals in the accompanying drawings include:

[0028] 1. Anchor cable; 2. Tensioning section; 3. Ground; 4. Waist beam; 5. Mounting seat; 51. First end face; 52. Second end face; 6. Positioning seat; 61. Clamping block; 62. Threaded rod; 63. Clamping port; 7. Positioning block; 8. Positioning disc; 9. Rotating disc; 10. Auxiliary line; 11. Mounting groove. Detailed Implementation

[0029] The present invention will be further described in detail below through specific embodiments:

[0030] In embodiments of the present invention, such as Figures 1-2 As shown, a prestressed anchor cable positioning structure is provided, wherein the anchor cable 1 includes an anchoring section, a free section, and a tensioning section 2, and the positioning structure includes:

[0031] The mounting base 5 has a first end face 51 and a second end face 52, and an internal space is formed between the first end face 51 and the second end face 52.

[0032] A clamping assembly is disposed on the first end face 51 and has a clamping port 63 that can provide clamping force;

[0033] A positioning block 7 is disposed in the clamping opening 63, and is used to suspend the positioning block 7 in the internal space via the clamping assembly;

[0034] The tensioning section 2 extends through the second end face 52 and into the internal space to connect with the positioning block 7. The tensioning section 2 is equipped with a tension force F. 预 The clamping assembly is configured to apply a radial clamping force N to the positioning block 7, and the contact surface between the positioning block 7 and the clamping assembly has a static friction coefficient μ, and the maximum static friction force μ·N applied by the clamping assembly to the positioning block 7 is greater than the tension force F of the tensioning section 2. 预 .

[0035] In this embodiment, the traditional prestressed anchor cable 1 is in a black box state after tensioning and locking, and the attenuation of its internal prestress cannot be directly perceived. In order to upgrade the prestressed anchor cable 1 from a single passive locking component to a structure with both active sensing and status indication functions, a mechanical, interference-resistant long-term monitoring solution is provided to replace expensive, fragile, and power-required electronic sensors. A preset and quantifiable early warning threshold is established to provide a clear and irreversible visual-physical alarm signal before substantial dangerous attenuation of the prestress occurs. Specifically, the mounting base 5 is arranged in opposite directions with a first end The anchor cable 1 has a first end face 51 and a second end face 52, forming an internal space. The first end face 51 is used to connect the support structure (such as the waist beam 4) and to install the clamping assembly. The second end face 52 is the entrance to the tensioning section 2 of the anchor cable 1. The internal space is equipped with the clamping assembly, which provides a clamping force N to suspend and clamp the positioning block 7 in the clamping opening 63. The tensioning section 2 is welded or anchored to the positioning block 7 through the second end face 52. By stretching the tensioning section 2, the anchor cable 1 is given prestress. Subsequently, the positioning block 7 has no rigid connection or friction with the mounting base 5 in the axial direction, and its axial balance depends entirely on F. 预 The clamping force N applied to the positioning block 7 by the clamping assembly is satisfied by the static friction coefficient μ of the contact surface between the positioning block 7 and the clamping assembly, and the maximum static friction force μ·N applied by the clamping assembly to the positioning block 7 is greater than the tension force F of the tensioning section 2. 预 When μ·N>F 预 The positioning block 7 is statically clamped within the clamping opening 63. When the prestress loss causes F 预 Descending to F 预When ≤μ·N, the positioning block 7 slides from the first end face 51 to the second end face 52, moving the F to be monitored. 预 The prestress state of anchor cable 1 is monitored by comparing it with the preset maximum static friction force μ·N and by intuitive mechanical movement.

[0036] The clamping assembly includes a positioning seat 6 and a plurality of clamping blocks 61 movably disposed on the positioning seat 6, each of the clamping blocks 61 being movably connected to the positioning seat 6 via a threaded rod 62.

[0037] In this embodiment, the positioning seat 6 is fixed to the first end face 51 of the mounting seat 5 by bolts. Four clamping blocks 61 and four threaded rods 62 are installed on the circumferential surface of the positioning seat 6. During installation, the operator rotates the threaded rods 62 to convert the rotational torque into a huge axial thrust. The thrust is converted into a radial clamping force N through the clamping blocks 61. The set clamping force N can clamp the positioning block 7 stably for a long time.

[0038] The contact surface between the clamping block 61 and the positioning block 7 is provided with a copper-based powder metallurgy liner.

[0039] In this embodiment, the copper-based powder metallurgy liner is a composite material with uniform composition and performance formed by mixing, pressing, and sintering powders such as copper (matrix), graphite (solid lubricant), iron, and tin using powder metallurgy technology. Its friction coefficient can be stably maintained in the range of 0.10 to 0.18 under dry or micro-lubricated conditions, and is far less affected by humidity and temperature changes than the friction between ordinary steel materials. It provides a predictable and reliable benchmark value for the friction coefficient μ, making it easy to calculate the maximum static friction force μ·N.

[0040] The inner wall of the second end face 52 is a tapered surface that gradually tapers away from the first end face 51.

[0041] In this embodiment, when F 预 When the value is ≤μ·N, the positioning block 7 begins to slide. Through the conical structure, the small axial displacement may be transformed into a significant radial position change. Observing the depth of the positioning block 7 entering the conical area can indirectly reflect the severity of the prestress loss and limit the positioning block 7.

[0042] The tensioning section 2 is provided with a positioning disk 8 and a rotating disk 9 at intervals away from the second end face 52, and multiple auxiliary lines 10 are provided between the two. The multiple auxiliary lines 10 are inclined and surround the tensioning section 2.

[0043] In this embodiment, positioning discs 8 and rotating discs 9 are spaced apart in the tensioning section 2. Multiple auxiliary lines 10 are arranged between the positioning discs 8 and rotating discs 9, encircling the tensioning section 2 to buffer against prestress failure and prevent breakage. Furthermore, the rotating disc 9 can be movably positioned relative to the positioning disc 8, allowing the auxiliary lines 10 to be linked to gradually tension the section and move the positioning disc 8 away from the rotating disc 9. The positioning disc 8 is fixed to the waist beam 4 or the ground 3, and an installation groove 11 is dug at the entrance of the anchor hole for installing the rotating disc 9.

[0044] Initially, the anchor cable 1 is tensioned and locked, and is in a taut state. The auxiliary line 10 is loosely wrapped around the tensioning section 2. The rotating disk 9 is in the initial position and remains stationary. The auxiliary line 10 is in a taut state and does not generate driving torque on the rotating disk 9. When the prestress of the anchor cable 1 decreases, its inherent elastic strain will be released, causing the tensioning section 2 to generate a small retraction force in the anchoring direction, which is converted into the rotational motion of the rotating disk 9. This causes the taut auxiliary line 10 to gradually straighten. This structure can be observed in the early stage of prestress disappearance, and the state of the anchor cable 1 can be predicted in advance.

[0045] This embodiment also provides a positioning method, which includes the prestressed anchor cable 1 positioning structure described above, comprising the following steps:

[0046] S1: Install the anchor cable 1 into the anchor hole, and connect the tension section 2 at the end of the anchor cable 1 to the positioning block 7 in the mounting base 5 and then fix it to the waist beam 4.

[0047] S2: Operate the clamping assembly so that its multiple clamping blocks 61 apply clamping force to the positioning block 7;

[0048] S3: Apply prestress to the tensioning section 2 of anchor cable 1 to the design value F. 预 And complete the anchoring;

[0049] S4: Tensioning section 2 maintains prestress F 预 In this state, adjust each clamping block 61 synchronously to increase its clamping force on the positioning block 7 until the following conditions are met:

[0050]

[0051] Where μ is the static friction coefficient between the contact surfaces of the positioning block 7 and the clamping block 61, N i The clamping force applied to the i-th clamping block 61, where n is the total number of clamping blocks 61, ensures that the maximum static friction force generated is greater than the current tension force F. 预 ;

[0052] S5; Positioning discs 8 and rotating discs 9 are set at intervals in the tensioning section 2, which is far from the fixed seat, and multiple auxiliary lines 10 are inclinedly wrapped around the tensioning section 2;

[0053] S6: After construction is completed, observe whether the positioning block 7 has shifted within the clamping opening 63.

[0054] In step S4, the clamping force Ni applied by each clamping block 61 is kept consistent by synchronously adjusting the rotation of each clamping block 61 through the motor.

[0055] In step S6, the length change of the auxiliary line 10 can be observed in the early stage of the disappearance of the prestress in the tensioning section 2. If the auxiliary line 10 is gradually tightened by the rotating disk 9, the prestress in the tensioning section 2 will gradually fail.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A prestressed anchor cable positioning structure, wherein the anchor cable comprises an anchoring section, a free section, and a tensioning section, characterized in that, The positioning structure includes: The mounting base has a first end face and a second end face, and an internal space of the mounting base is formed between the first end face and the second end face. A clamping assembly is disposed on the first end face and has a clamping opening that can provide clamping force; A positioning block is disposed in the clamping opening, so that the positioning block is suspended in the internal space by the clamping assembly; The tensioning section extends through the second end face and into the internal space to connect with the positioning block. The tensioning section is equipped with a tension force F. 预 The clamping assembly is configured to apply a radial clamping force N to the positioning block, and the contact surface between the positioning block and the clamping assembly has a static friction coefficient μ, and the maximum static friction force μ·N applied by the clamping assembly to the positioning block is greater than the tension force F of the tensioning section. 预 .

2. The prestressed anchor cable positioning structure as described in claim 1, characterized in that, The clamping assembly includes a positioning seat and a plurality of clamping blocks movably disposed on the positioning seat, each of the clamping blocks being movably connected to the positioning seat via a threaded rod.

3. The prestressed anchor cable positioning structure as described in claim 2, characterized in that, The contact surface between the clamping block and the positioning block is provided with a copper-based powder metallurgy liner.

4. The prestressed anchor cable positioning structure as described in claim 1, characterized in that, The inner wall of the second end face is a tapered surface that gradually tapers away from the first end face.

5. A prestressed anchor cable positioning structure as described in claim 1, characterized in that, The tensioning section is provided with a positioning disk and a rotating disk at intervals away from the second end face, as well as multiple auxiliary lines disposed between the two, and the multiple auxiliary lines are inclined and surround the tensioning section.

6. A prestressed anchor cable positioning structure as described in claim 5, characterized in that, The rotating disk can be movably set relative to the positioning disk to gradually tension the auxiliary line and move the positioning disk away from the rotating disk.

7. A positioning method, comprising the prestressed anchor cable positioning structure as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: Install the anchor cable into the anchor hole, and connect the tension section at the end of the anchor cable to the positioning block in the mounting seat and then fix it to the waist beam; S2: Operate the clamping assembly to cause its multiple clamping blocks to apply clamping force to the positioning block; S3: Apply prestress to the tensioning section of the anchor cable up to the design value F. 预 And complete the anchoring; S4: Tensioning section maintains prestress F 预 In this state, adjust each clamping block synchronously to increase its clamping force on the positioning block until the following conditions are met: Where μ is the static friction coefficient between the contact surfaces of the positioning block and the clamping block, N i The clamping force applied to the i-th clamping block, where n is the total number of clamping blocks, ensures that the maximum static friction force generated is greater than the current tension force F. 预 ; S5; Positioning discs and rotating discs are set at intervals in the tensioning section away from the fixed seat, and multiple auxiliary lines are inclinedly wrapped around the tensioning section; S6: After construction is completed, observe whether the positioning block has shifted within the clamping opening.

8. The positioning method according to claim 7, characterized in that, In step S4, the motor synchronously adjusts the rotation of each clamping block to ensure that the clamping force N applied by each clamping block is constant. i Maintain consistency.

9. The positioning method according to claim 7, characterized in that, In step S6, the length change of the auxiliary line can be observed in the early stage of the disappearance of the prestress in the tensioning section. If the auxiliary line is gradually tightened by the rotating disk, the prestress in the tensioning section will gradually fail.

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