High-strength stable-resistance energy-absorbing anchor cable and supporting method thereof

Abstract

The present application relates to a kind of high-strength stable resistance energy-absorbing anchor cable and its supporting method, belong to mine and tunnel engineering supporting technical field.The anchor cable includes anchor cable body, steel sleeve, anchor device slidingly arranged in the inner cavity of steel sleeve, steel ball between the inner wall of steel sleeve and the outer wall of anchor device, and anchor device ring at the end of steel sleeve.When the anchor cable is pulled to reach the set stress, anchor device extrudes steel ball to move along the axial direction of steel sleeve, until embedded in anchor device ring, to realize constant resistance pressure relief function.Steel ball is divided into two rows, the diameter of front row is larger, the diameter of rear row is smaller, and the outer wall of anchor device is provided with annular groove to stabilize steel ball.The hardness of steel ball is higher than steel sleeve and anchor device, to ensure its stable work under high stress.The anchor cable generates constant resistance by the initial pre-tightening force of anchor device compressing steel ball, and absorbs energy by sliding steel ball driven by anchor device when surrounding rock deforms, finally locked as rigid supporting state.The present application solves the problem that traditional anchor cable is easy to brittle fracture and lacks constant supporting resistance under high stress condition.

Description

Technical Field

[0001] This invention relates to the field of support technology for mining and tunnel engineering, and in particular to a high-strength, stable, energy-absorbing anchor cable and its support method. Background Technology

[0002] As shallow resources gradually deplete, the development of deep mineral resources has become an important direction of the national energy strategy. However, the high ground stress environment faced by deep mining causes severe deformation of the surrounding rock in the tunnels, and existing support technologies are difficult to adapt to such complex conditions. The elongation rate of traditional anchor cables is usually only 3.5%-7%, and they are prone to brittle fracture under continuous high stress. Even if the total elongation rate of new high-elongation anchor cables is increased to 8.1%, it still cannot meet the large deformation requirements of deep tunnels, which often exceed 10%. Conventional anchor cables experience a sharp drop in bearing capacity after reaching peak strength under load, and lack the ability to maintain constant support resistance under geological tectonic activity or mining-induced stress disturbances, resulting in low efficiency of coordinated deformation between the surrounding rock and the support system. Existing pressure relief devices mostly rely on a single energy-absorbing element (such as a plastic deformation structure or friction pair), which has low energy dissipation efficiency and is prone to failure due to coal and rock debris contamination or cumulative damage. For example, the friction resistance of a conical friction constant resistance device is significantly unstable due to environmental influences, and while shear pin energy-absorbing devices can accurately control the pressure relief threshold, they cannot be reused. Furthermore, traditional constant-resistance structures generally lack an intelligent conversion mechanism from "flexible yielding" to "rigid bearing," making it difficult to form a high-strength anchoring system after the yielding stage. How to achieve coordinated control between high preload application and large deformation adaptation has become a pressing technical challenge in the field of deep tunnel support. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-strength, stable, energy-absorbing anchor cable and its support method. By installing a steel sleeve at the end of the anchor cable and setting a movable anchor and steel ball therein, an effective constant resistance and pressure relief function is achieved under high stress and large deformation conditions, thereby improving the safety and stability of roadway support.

[0004] To achieve the above objectives, in a first aspect, the present invention provides a high-strength, stable, energy-absorbing anchor cable, comprising:

[0005] Anchor cable body;

[0006] A steel sleeve is fitted onto the outer side of the end of the anchor cable body, and the steel sleeve has an inner cavity;

[0007] An anchor is slidably disposed within the inner cavity of a steel sleeve, and the anchor is connected to the end of the anchor cable body;

[0008] The steel balls are located in the annular space between the inner wall of the steel sleeve and the outer wall of the anchor.

[0009] Anchorage ring, located at the end of the steel sleeve, and the other end is fixed on the surrounding rock;

[0010] When the anchor body is tensioned to a set stress, the anchor extrudes the steel ball to move axially along the steel sleeve until the anchor is embedded in the anchor ring.

[0011] Beneficial effect: By sliding the anchor in the steel sleeve and extruding the steel ball, the constant resistance and pressure relief function of the anchor cable under high stress is realized, effectively absorbing the deformation energy of the surrounding rock, and converting into rigid support after the anchor is embedded in the anchor ring, improving the adaptability and safety of the support structure. This structural design enables the anchor cable to realize constant resistance and pressure relief function under high stress and large deformation environment, effectively absorbing and releasing the surrounding rock pressure, protecting the main body from damage, while after the anchor is embedded in the anchor ring, it can also be converted into a conventional anchor cable to continue to play a supporting role, improving the adaptability and reliability of the anchor cable.

[0012] Further, the steel ball is provided with two rows, divided into front row steel ball and rear row steel ball, wherein the diameter of the front row steel ball is larger than that of the rear row steel ball, and the two rows of steel balls are arranged in sequence along the moving direction of the anchor.

[0013] Beneficial effect: By setting two rows of steel balls with different diameters, the front row of large diameter steel balls provides initial resistance, and the rear row of small diameter steel balls maintains subsequent stability, achieving more precise resistance control and improving constant resistance effect.

[0014] Further, the outer wall of the anchor is provided with an annular groove, and the front row of steel balls is partially embedded in the annular groove, and the rear row of steel balls is in contact with the outer wall of the anchor.

[0015] Beneficial effect: The annular groove fixes the front row of steel balls to prevent them from falling off during movement, and the rear row of steel balls in contact with the outer wall of the anchor increases the friction force, further improving the stability of the resistance.

[0016] Further, the anchor ring is provided with a through hole in the center, and one end of the anchor body passes through the through hole on the anchor ring, and a gap is left between the through hole and the anchor body, and the outer contour of the anchor is matched with the gap.

[0017] Beneficial effect: The design of the through hole and the gap ensures that the anchor can be smoothly embedded in the anchor ring to realize the locking function and complete the smooth transition from constant resistance and pressure relief to rigid support.

[0018] Further, the hardness of the steel ball is higher than that of the inner wall of the steel sleeve and the outer wall of the anchor.

[0019] Beneficial effect: The steel ball with higher hardness than the inner wall of the steel sleeve and the outer wall of the anchor can cut or deform the inner wall of the sleeve during movement, ensuring the constancy of resistance and improving the energy absorption efficiency.

[0020] Further, the end of the steel sleeve is expanded to form a flared section corresponding to the installation position of the anchor ring.

[0021] Beneficial effect: improves the stability between the steel sleeve and the anchor ring.

[0022] Further, the depth of the annular groove is 1 / 3 to 1 / 2 of the diameter of the front row of steel balls.

[0023] Beneficial effect: the appropriate groove depth not only ensures the stability of the steel balls, but also allows necessary movement, ensuring the flexibility and stability of the anchor cable under high stress conditions.

[0024] Further, the second aspect of the present application also provides a supporting method based on the high-strength stable resistance energy-absorbing anchor cable of any one of the first aspect, comprising the following steps:

[0025] S1. Drilling a hole in the surrounding rock and inserting the anchor cable body, with the steel sleeve located at the hole;

[0026] S2, apply initial pretightening force to compress the steel balls to generate constant resistance;

[0027] S3, when the surrounding rock deforms and causes the anchor cable to be pulled, the anchor drives the steel balls to slide along the steel sleeve to absorb energy;

[0028] S4, the anchor is locked when it moves to the anchor ring position, and becomes a rigid support state.

[0029] Beneficial effect: the supporting method provided by the present application realizes the dynamic conversion of constant resistance energy absorption and rigid support of the anchor cable in a high stress and large deformation environment, ensuring the stability and safety of the anchor cable, not only simplifying the construction steps, but also effectively absorbing energy in practical application, protecting the surrounding rock from damage, and improving the reliability and durability of the support.

[0030] Further, the initial pretightening force in step S2 is 20%-30% of the breaking strength of the anchor cable, and the pretightening force error controlled by the torque wrench is ≤5%.

[0031] Beneficial effect: by accurately controlling the initial pretightening force, the anchor cable is ensured to be in the best working state after installation, improving the reliability and consistency of the supporting effect.

[0032] Further, in step S3, the constant resistance F generated by the sliding of the steel balls satisfies:

[0033] F = n·μ·P

[0034] Wherein, n is the number of rows of steel balls, μ is the friction coefficient between the steel balls and the sleeve, and P is the normal pressure of a single row of steel balls.

[0035] Further, after the anchor fitting is embedded in the anchor fitting ring in step S4, the elongation of the anchor cable is increased to 8%-12%, and the residual supporting force is greater than or equal to 90% of the initial constant resistance.

[0036] In summary, compared with the prior art, the high-strength stable-resistance energy-absorbing anchor cable of the present application can realize high-strength, stable and constant-resistance energy-absorbing functions in a high-stress and large-deformation environment. Through the synergistic effect of the anchor cable body, the steel sleeve, the anchor fitting, the steel ball and the anchor fitting ring, the anchor cable can not only absorb the deformation energy of the surrounding rock, but also convert into rigid support when necessary, significantly improving the safety and adaptability of deep roadway support. In addition, by adjusting the material and structural parameters, customized requirements of different constant resistances can be realized, further serving the high-stress and large-deformation roadway support work in deep resource mining. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a high-strength stable-resistance energy-absorbing anchor cable of the present application;

[0038] Figure 2 is an anchor fitting ring in a high-strength stable-resistance energy-absorbing anchor cable of the present application;

[0039] Figure 3 is an anchor fitting and a steel sleeve in a high-strength stable-resistance energy-absorbing anchor cable of the present application;

[0040] Figure 4 is an anchor fitting and a steel ball in a high-strength stable-resistance energy-absorbing anchor cable of the present application;

[0041] Label explanation: 1-anchor cable, 2-anchor fitting ring, 3-steel sleeve, 4-steel ball, 5-anchor fitting, 6-rock stratum. DETAILED DESCRIPTION

[0042] The present application will be further described below in conjunction with the drawings. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0043] In the description of the present application, it should be understood that the terms "center", "axial", "transverse", "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only for description purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0044] In the description of the invention, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] As shown in Figures 1-4 The embodiment of the present application provides a high-strength stable-resistance energy-absorbing anchor cable, which comprises:

[0046] The anchor cable body 1;

[0047] The steel sleeve 4 is sleeved outside the end of the anchor cable body 1, and the steel sleeve 4 has an inner cavity;

[0048] The anchor 3 is slidingly arranged in the inner cavity of the steel sleeve 4, and the anchor 3 is connected with the end of the anchor cable body 1;

[0049] The steel ball 2 is arranged in the annular space between the inner wall of the steel sleeve 4 and the outer wall of the anchor 3; the presence of the steel ball 2 can effectively disperse the pressure and reduce the wear.

[0050] The anchor ring 5 is located at the end of the steel sleeve 4, and the other end is fixed to the surrounding rock 6;

[0051] When the anchor cable 1 reaches the critical stress under tensile stress, the anchor 3 and the steel ball 2 move forward, so as to realize the constant resistance and pressure relief function of the anchor cable under high stress and large deformation; when the anchor 3 moves to the end of the bottom rock layer 6, the anchor 3 is embedded into the anchor ring 5, becoming a conventional anchor cable; the tensile deformation characteristics of the anchor cable thereafter are mainly controlled by the structure and mechanical characteristics of the anchor cable itself, and the function of the constant resistance and pressure relief anchor cable under high stress is realized through the movement of the steel ball 2 at the end of the anchor cable and the anchor 3. The present application can realize the constant resistance and pressure relief anchor cable in a high-stress and large-deformation roadway.

[0052] Specifically, the steel ball 2 is provided with two rows, which are divided into front row steel balls and rear row steel balls, wherein the diameter of the front row steel balls is greater than the diameter of the rear row steel balls, and the two rows of steel balls are arranged in sequence along the moving direction of the anchor 3.

[0053] Further, the outer wall of the anchor 3 is provided with an annular groove, the front row steel balls are partially embedded in the annular groove, and the rear row steel balls are in contact with the outer wall of the anchor 3. The annular groove limits the steel balls in the anchor 3, ensuring that the steel balls 2 will not easily fall off the position during the stress process.

[0054] Further, the anchor ring 5 is provided with a through hole in the center, and one end of the anchor cable body 1 passes through the through hole on the anchor ring 5, leaving a gap between the through hole and the anchor cable body 1, and the outer contour of the anchor 3 is matched with the gap.

[0055] Specifically, the hardness of the steel ball 2 is higher than the hardness of the inner wall of the steel sleeve 4 and the outer wall of the anchor 3.

[0056] Specifically, the end of the steel sleeve 4 is expanded in diameter to form a flared section, which corresponds to the installation position of the anchor ring 5.

[0057] Further, the depth of the annular groove is 1 / 3 to 1 / 2 of the diameter of the front row of steel balls.

[0058] As an embodiment, a supporting method of a high-strength stable-resistance energy-absorbing anchor cable includes the following steps:

[0059] S1, drilling a hole in the surrounding rock and inserting an anchor cable body 1, so that the steel sleeve 4 is located at the hole;

[0060] S2, applying an initial pre-tightening force to compress the steel ball 2 to generate a constant resistance;

[0061] S3, when the surrounding rock deforms and causes the anchor cable to be pulled, the anchor 3 drives the steel ball 2 to slide along the steel sleeve 4 to absorb energy;

[0062] S4, the anchor 3 is locked when it moves to the position of the anchor ring 5, and becomes a rigid support state.

[0063] Further, in step S2, the initial pre-tightening force is 20%-30% of the breaking strength of the anchor cable, and the pre-tightening force error controlled by the torque wrench is ≤5%.

[0064] Further, in step S3, the constant resistance F generated by the sliding of the steel ball satisfies:

[0065] F=n·μ·P

[0066] Wherein, n is the number of steel ball rows, μ is the friction coefficient between the steel ball and the sleeve, and P is the normal pressure of a single row of steel balls.

[0067] Further, in step S4, after the anchor is embedded in the anchor ring, the elongation of the anchor cable is increased to 8%-12%, and the residual support force is ≥90% of the initial constant resistance.

[0068] It is to be noted that, in the present text, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0069] The above description is only the preferred embodiment of the present application, it should be pointed out that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A high-strength stable resistance energy-absorbing anchor cable, characterized in that, The application relates to a steel sleeve (4) sleeved outside the end of an anchor cable body (1), wherein the steel sleeve (4) has an inner cavity; an anchor device (3) is slidingly arranged in the inner cavity of the steel sleeve (4) and connected with the end of the anchor cable body (1); a steel ball (2) is arranged in the annular space between the inner wall of the steel sleeve (4) and the outer wall of the anchor device (3); an anchor device ring (5) is arranged at the end of the steel sleeve (4) and fixed to surrounding rock (6) at the other end; when the anchor cable body (1) is pulled to a set stress, the anchor device (3) extrudes the steel ball (2) to move along the axis of the steel sleeve (4) until the anchor device (3) is embedded in the anchor device ring (5); the steel ball (2) is arranged in two rows, namely front-row steel balls and rear-row steel balls, wherein the diameter of the front-row steel balls is larger than that of the rear-row steel balls, and the two rows of steel balls are arranged in sequence along the moving direction of the anchor device (3); the outer wall of the anchor device (3) is provided with an annular groove, and the front-row steel balls are partially embedded in the annular groove, and the rear-row steel balls are in contact with the outer wall of the anchor device (3). A through hole is arranged at the center of the anchor device ring (5), and one end of the anchor cable body (1) passes through the through hole on the anchor device ring (5), and a gap is left between the through hole and the anchor cable body (1), and the outer contour of the anchor device (3) is matched with the gap.

2. The high-strength stable-resisting energy-absorbing anchor cable according to claim 1, characterized in that, The hardness of the steel ball (2) is higher than that of the inner wall of the steel sleeve (4) and the outer wall of the anchor device (3).

3. The high-strength stable-resisting energy-absorbing anchor cable according to claim 1, characterized in that, The end of the steel sleeve (4) is expanded to form an expanded section, and the expanded section corresponds to the mounting position of the anchor device ring (5).

4. The high-strength stable-resisting energy-absorbing anchor cable according to claim 1, characterized in that, The depth of the annular groove is 1 / 3 to 1 / 2 of the diameter of the front-row steel balls.

5. The high-strength stable-resisting energy-absorbing anchor cable according to claim 1, characterized in that, The application further discloses a method for installing the anchor device, which comprises the following steps:

6. A supporting method based on the high-strength stable-resistance energy-absorbing anchor cable according to any one of claims 1-5, characterized in that, S1, drilling surrounding rock and inserting the anchor cable body (1) so that the steel sleeve (4) is located at the hole mouth; S2, applying an initial pre-tightening force to compress the steel ball (2) to generate a constant resistance; S3, when the surrounding rock is deformed to cause the anchor cable to be pulled, the anchor device (3) drives the steel ball (2) to slide along the steel sleeve (4) to absorb energy; and S4, when the anchor device (3) moves to the position of the anchor device ring (5), the anchor device (3) is locked and changes to a rigid supporting state. In step S2, the initial pre-tightening force is 20%-30% of the breaking strength of the anchor cable, and the pre-tightening force error controlled by a torque wrench is less than or equal to 5%.

7. The supporting method of the high-strength stable-resistance energy-absorbing anchor cable according to claim 6, characterized in that, In step S3, the constant resistance F generated by the sliding of the steel ball satisfies the formula: F=n*mu*P, wherein n is the number of rows of the steel balls, mu is the friction coefficient of the steel ball and the sleeve, and P is the normal pressure of a single row of steel balls.

8. The supporting method of the high-strength stable-resistance energy-absorbing anchor cable according to claim 6, characterized in that, ​

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