Anchoring structure self-adaptive to large deformation

Abstract

The self-adaptive large-deformation anchoring structure has the following force characteristics in the supporting effect on surrounding rock: when the anchor rod is mounted, the rod body of the anchor rod and the surrounding rock are in a full-length anchoring state; in the mutual mechanical coupling deformation process between the anchor rod and the surrounding rock, the anchoring effect between the rod body of the anchor rod and the surrounding rock changes along with the strain rate of the anchor rod, which is shown as follows: when the rod body of the anchor rod locally has accelerated tensile deformation under the action of the surrounding rock, namely, the axial strain rate of a certain position of the rod body is increased, the anchor rod is anchored; the anchoring effect between the rod body in the local range and the surrounding rock is weakened until the anchoring effect is lost, so that the local rod body in the local range is represented as a free section without the anchoring effect; and when the tensile deformation of the local anchor rod at the position is slowed down, namely the axial strain rate at the position of the rod body is reduced, the anchoring effect between the local rod body and the surrounding rock is gradually recovered, so that the rod body at the position is recovered to the anchoring section with the anchoring effect. And mutual conversion between the free section and the anchoring section is achieved.

Description

Technical Field

[0001] This application relates to the field of anchorage support, specifically to an adaptive large deformation anchorage structure. Background Technology

[0002] Anchoring supports play a crucial role in controlling the stability and deformation of surrounding rock. Full-length bonded anchoring structures offer good stability and deformation control, but they struggle to withstand large local deformations, leading to anchoring failure. End-anchored structures, with their longer free sections, allow for greater deformation, enabling them to withstand large rock deformations while maintaining support. Furthermore, the ample space in the free section facilitates the creation of large-deformation anchors (cables) through material and structural design, making them widely used in engineering. However, end-anchored anchors offer less stability and deformation control compared to full-length bonded anchors.

[0003] To address the aforementioned advantages and disadvantages, some scholars have proposed a structure that transforms fully bonded anchor bolts into end-anchored anchor bolts. This involves the anchor bolt body in a specific functional area detaching from the borehole wall under the deformation of the surrounding rock, transforming that area into a free section. However, the transition from a bonded to a free state is unidirectional and irreversible; the free section cannot re-bond to the rock wall. Furthermore, the spatial location of this transition (i.e., the relative positions of the anchored and free sections to the surrounding rock after the transition) is artificially determined and immutable, potentially failing to meet the requirements of surrounding rock deformation. Summary of the Invention

[0004] In view of this, this application provides an adaptive large deformation anchoring structure, in which the free section and the anchoring section can be transformed into each other, so as to better control the stability and deformation of the surrounding rock.

[0005] To achieve the above objectives, this application provides the following technical solution: An adaptive large deformation anchoring structure, comprising: Anchor bolts are used to provide anchoring support for the surrounding rock. When the anchor is installed in the surrounding rock, it is fully anchored to the surrounding rock. In the first stage when the surrounding rock undergoes axial deformation, the anchoring effect between at least one part of the anchor and the surrounding rock decreases until it is lost, and the at least one part changes from an anchored section to a free section. In the second stage when the surrounding rock undergoes axial deformation, the anchoring effect between the at least one part and the surrounding rock increases until it is restored, and the at least one part changes from a free section to an anchored section. This achieves the mutual transformation between the free section and the anchored section. In chronological order, the first stage precedes the second stage, and the axial strain rate of the anchor in the first stage is greater than that of the anchor in the second stage.

[0006] Optionally, in the above-mentioned adaptive large deformation anchoring structure, the anchor rod includes an inner core and an outer layer. The inner core can be stretched along the axial direction, and the outer layer is sleeved on the outside of the inner core and connected to the anchoring agent. The outer layer is provided with an axially expandable and contractible axial deformation member and a radially deformable radial deformation member. In the first stage, the axial deformation member undergoes axial tensile deformation, which in turn causes the radial deformation member to undergo axial tensile deformation and radial contraction deformation, thereby separating the outer layer of the rod from the anchoring agent and reducing the force between the inner core of the rod and the outer layer of the rod. In the second stage, the axial tensile force on the axial deformation member is reduced compared to the axial tensile force on the axial deformation member in the first stage, resulting in a reduction in the axial tensile deformation of the radial deformation member compared to the axial tensile deformation of the radial deformation member in the first stage. Furthermore, the radial deformation member undergoes radial expansion, causing the outer layer of the rod to re-compress the anchoring agent and the inner core of the rod, thereby providing shear anchoring between the outer layer of the rod and the anchoring agent and transferring the anchoring force to the inner core of the rod.

[0007] Optionally, in the above-mentioned adaptive large deformation anchoring structure, the change in axial tensile force within the outer layer material of the rod is as follows:

[0008] in, ; —The axial strain rate of the outer layer of the rod; —Axial strain of the outer layer of the rod; —The axial elastic stiffness coefficient of the outer layer of the rod; —The axial viscosity coefficient of the outer layer of the rod; —The effective cross-sectional area of ​​the outer layer of the rod.

[0009] Optionally, in the above-mentioned adaptive large deformation anchoring structure, the radial deformation member is connected to the axial deformation member along the axial direction and is arranged alternately at equal intervals.

[0010] Optionally, in the above-mentioned adaptive large deformation anchoring structure, the distance between adjacent radial deformation members is equal along the axial direction; and the radial deformation members are evenly distributed along the circumferential direction.

[0011] Optionally, in the above-mentioned adaptive large deformation anchoring structure, the radial deformation component includes a shuttle-shaped steel clip, and the axial deformation component includes carbon fiber resin. The carbon fiber resin and the shuttle-shaped steel clip are axially connected in series and are distributed alternately at equal intervals.

[0012] Optionally, in the above-mentioned adaptive large deformation anchoring structure, the core of the rod includes multiple steel fibers and steel hoops, and the steel hoops are used to bind the multiple steel fibers.

[0013] At the moment of installation, the anchor bolt is fully anchored to the surrounding rock (including mechanical anchoring, adhesive anchoring, etc.). During the mutual mechanical coupling deformation between the anchor bolt and the surrounding rock, the anchoring effect changes with the strain rate of the anchor bolt itself. Specifically: First, when at least a part of the anchor bolt undergoes accelerated tensile deformation under the action of the surrounding rock, i.e., when the axial strain rate at a certain point in the bolt increases, the anchoring effect between the bolt and the surrounding rock in that local area weakens until it is lost (i.e., the adhesive or mechanical friction between the bolt and the inner wall of the anchor hole in that local area decreases until it is lost). This makes that local section of the bolt appear as a free section without anchoring effect. Second, when the tensile deformation of the anchor bolt slows down at that point, i.e., when the axial strain rate at that point decreases, the anchoring effect between the local section of the bolt and the surrounding rock gradually recovers. This makes that section of the bolt return to an anchored section with anchoring effect. The above mechanical evolution mechanism can change multiple times between the first and second states. When a section of the anchor rod is in a free segment without anchoring due to accelerated fracturing and deformation of the surrounding rock, this segment of the anchor rod possesses a large deformation mechanism. It can elongate under the tensile force of the surrounding rock and maintain a high support reaction force. In this way, the free segment and the anchored segment of the anchoring structure can be transformed into each other, and combined with the large deformation mechanism, it is possible to better control the deformation and stability of the surrounding rock. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the local large deformation of a full-length anchor bolt anchoring structure in the prior art; Figure 2 A comparison diagram showing the anchoring principle of the existing anchoring structure and the anchoring principle of the anchoring structure of this application; Figure 3 A schematic diagram of an anchoring structure provided in this application; Figure 4A structural schematic diagram of an anchoring structure provided in this application; Figure 5 for Figure 4 Another structural diagram from another perspective; Figure 6 This is a structural schematic diagram and a principle comparison diagram of the anchoring mechanism of this application; Figure 7 A schematic diagram illustrating the mutual transformation between the free section and the anchorage section of the anchorage structure provided in this application.

[0016] exist Figures 1-7 middle: 1. Anchor bolt; 11. Inner core of the bolt; 12. Outer layer of the bolt; 2. Anchoring agent; 3. Axial deformation component; 4. Radial deformation component; 5. Surrounding rock; 111. Steel fiber; 112. Steel hoop; 31. Carbon fiber resin; 41. Shuttle-shaped steel clip. Detailed Implementation

[0017] This application discloses an adaptive large deformation anchoring structure, in which the free section and the anchoring section can be mutually converted, so as to better control the stability and deformation of the surrounding rock.

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] like Figure 1 As shown, a common full-length anchor bolt 1 is bonded to the borehole wall via an anchoring agent 2. When the radial strain of a certain area (fractured zone & loosened zone) of the surrounding rock 5... Significantly increased (strain rate) (Increased height) Because the surrounding rock 5 and anchor rod 1 are fully anchored, anchor rod 1 deforms along with the surrounding rock 5, causing the axial stress of anchor rod 1 in this area to increase rapidly. For a typical fully anchored carbon steel anchor rod 1, excessive axial stress in this area may lead to fracture, resulting in structural support failure. In this case, it can be assumed that the interaction between anchor rod 1 and the rock wall of the anchor hole is formed by the connection of spring and friction block, and the deformation ultimately leads to the fracture of anchor rod 1 or the detachment of anchor rod 1 from the anchoring agent 2.

[0020] Based on this, it is assumed that the bond between anchor rod 1 and the surrounding rock 5 in the region where the strain rate increases can be broken, making this section of anchor rod 1 a free segment without external force and possessing a large deformation mechanism to prevent structural failure. This allows anchor rod 1 to function normally as a free segment with large deformation. However, under normal stable engineering conditions, the deformation of the surrounding rock 5 will not increase indefinitely but will gradually converge, meaning the strain rate of the surrounding rock 5 will approach zero. At this point, if the bond between anchor rod 1 and the surrounding rock 5 is restored, it can provide better support for the surrounding rock 5, significantly controlling rock fragmentation and reducing rock deformation.

[0021] Based on this principle, during the deformation of the surrounding rock 5, if a mechanism is designed to allow the interaction force between the anchor bolt 1 and the rock wall to switch on and off according to the strain rate of the anchor bolt 1, such as... Figure 2 As shown, the left side is a schematic diagram of the anchoring principle of an existing anchoring structure, and the right side is a schematic diagram of the anchoring principle of the anchoring structure of this application. A clutch switch is added to the contact model between the anchor rod 1 and the borehole inner wall, so that the normal contact force between the anchor rod 1 and the rock wall is... It is the axial tensile strain rate of anchor bolt 1 under the action of the rock wall. Function. When the strain rate is large, the clutch disengages, and anchor bolt 1 detaches from the rock wall. =0, this section of anchor 1 becomes a free section, and as the surrounding rock stretches and deforms, the anchors 1 at both ends of this free section provide support reaction force to the surrounding rock. When the secondary stress field of the surrounding rock and the support reaction force gradually reach equilibrium, the deformation of the surrounding rock gradually stops, and at this time the axial tensile strain rate of anchor 1... As the pressure gradually decreases and approaches zero, the clutch gradually closes, and anchor bolt 1 regains contact with the rock wall. >0, at which point the free segment reverts to the anchored segment.

[0022] Based on the above design principles, there are many types of structures, materials, and methods for realizing this type of anchor bolt 1. In principle, designs that conform to the above principles fall within the protection scope of this invention. To illustrate the feasibility of this invention, a specific structural example is given here. The structural design mechanism is as follows: Figure 3 As shown, the anchor rod 1 has a two-layer structure, with the inner layer being a rod body with a certain degree of elasticity and large deformation (rod core 11) and the outer layer being a structural material with Maxwell mechanical properties (rod outer layer 12). This material is located between the rod core 11 and the anchoring agent 2 of the anchor rod 1, and forms a radial expansion and compression effect on the rod core 11 and the anchoring agent 2, and forms shear resistance through the pawl.

[0023] like Figure 3 As shown, when the radial strain rate of the surrounding rock 5 where the anchor bolt 1 is located is low or close to 0, the viscous elements in the outer layer material... With no tension, the rhomboid deformation mechanism is in the spring. Under the action of axial contraction force, radial expansion deformation occurs, causing the outer pawl of the outer layer 12 of the rod to squeeze the anchoring agent 2, and the inner pawl to squeeze the inner core 11 of the rod, thereby achieving full-length anchoring. When a certain area of ​​the surrounding rock 5 fractures, generating a large radial strain rate, the viscous element generates tensile stress, the spring is forced to stretch and elongate, driving the rhomboid deformation mechanism to generate radial contraction deformation, causing the outer pawl of the outer layer 12 of the rod to detach from the anchoring agent 2, and the inner pawl to detach from the inner core 11 of the rod. At this time, the anchor rod 1 in the area of ​​rapid strain debonds from the surrounding rock 5, forming a free deformation section in this area. Since the inner core 11 of the rod has a large deformation mechanism, it allows for large deformation, thereby coping with the large deformation of the surrounding rock 5 in the area.

[0024] The above can also be understood as follows: At the moment of installation, anchor 1 is fully anchored to the surrounding rock 5 (including mechanical anchoring, adhesive anchoring, etc.). During the mutual mechanical coupling deformation between anchor 1 and the surrounding rock 5, the anchoring effect between anchor 1 and the surrounding rock 5 changes with the strain rate of anchor 1 itself. Specifically: First, when at least one part of anchor 1 undergoes accelerated tensile deformation under the action of the surrounding rock 5, i.e., when the axial strain rate at a certain point of anchor 1 increases, the anchoring effect between anchor 1 and the surrounding rock 5 in that local area weakens until it is lost (i.e., the adhesive or mechanical friction between the anchor body and the inner wall of the anchor hole in the surrounding rock 5 decreases until it is lost). This makes the local anchor 1 at that point a free section without anchoring effect. Second, when the tensile deformation of the local anchor 1 slows down, i.e., when the axial strain rate at that point of anchor 1 decreases, the anchoring effect between the local anchor 1 and the surrounding rock 5 gradually recovers. This makes the local anchor 1 return to an anchored section with anchoring effect. The aforementioned mechanical evolution mechanism can transform multiple times between the first and second states. When a section of the anchor rod 1 is in a free segment without anchoring due to accelerated fracturing and deformation of the surrounding rock 5, this segment of the anchor rod 1 possesses a large deformation mechanism, capable of elongating under the tensile force of the surrounding rock 5 while maintaining a high support reaction force. In this way, the free segment and the anchored segment of the anchoring structure can transform into each other, combined with the large deformation mechanism, to better control the deformation and stability of the surrounding rock.

[0025] Specifically, such as Figures 2-7As shown, this application provides an adaptive large deformation anchoring structure, including an anchor rod 1 for anchoring and supporting the surrounding rock 5. When the anchor rod 1 is installed in the surrounding rock 5, it is fully anchored along its length. In the first stage of deformation of the surrounding rock 5, the anchoring effect between at least a portion of the anchor rod 1 and the surrounding rock 5 decreases until it is lost, and at least a portion changes from an anchored section to a free section. In the second stage of deformation of the surrounding rock 5, the anchoring effect between at least a portion of the anchor rod 1 and the surrounding rock 5 increases until it is restored, and at least a portion changes from a free section to an anchored section, thereby achieving the mutual conversion between the free section and the anchored section. Furthermore, in chronological order, the first stage precedes the second stage, and the axial strain rate of the anchor rod 1 in the first stage is greater than the axial strain rate of the anchor rod 1 in the second stage.

[0026] Furthermore, the anchor bolt 1 includes: an inner core 11, which is axially stretchable; an outer layer 12, which is sleeved on the outside of the inner core 11 and connected to the anchoring agent 2; the outer layer 12 is provided with an axially expandable and contractile axial deformation member 3 and a radially deformable radial deformation member 4; wherein, in the first stage, the axial deformation member 3 undergoes axial tensile deformation, which in turn causes the radial deformation member 4 to undergo axial tensile deformation and radial contraction deformation, so as to separate the outer layer 12 from the anchoring agent 2 and reduce the tension between the inner core 11 and the anchor bolt. The forces between the outer layers 12; in the second stage, the axial tensile force on the axial deformation member 3 is reduced compared to the axial tensile force on the axial deformation member 3 in the first stage, so that the axial tensile deformation of the radial deformation member 4 is reduced compared to the axial tensile deformation of the radial deformation member 4 in the first stage, and the radial deformation member 4 undergoes radial expansion, so that the outer layer 12 of the rod re-compresses the anchoring agent 2 and the inner core 11 of the rod, thereby giving the outer layer 12 of the rod and the anchoring agent 2 a shear anchoring effect, and transferring the anchoring force to the inner core 11 of the rod.

[0027] In other words, in the first stage, under the action of fracture deformation of the surrounding rock 5, the axial tensile strain rate of the outer layer 12 of the anchor rod 1 increases relative to when the surrounding rock 5 is not deformed, the axial tensile force of the axial deformation component 3 increases, and drives the radial deformation component 4 to undergo axial tensile deformation and radial contraction deformation, so that the outer layer 12 of the rod separates from the anchoring agent 2, and reduces the force between the inner core 11 of the rod and the outer layer 12 of the rod. In the second stage, the axial tensile strain rate of the outer layer 12 of the anchor rod 1 decreases compared to the tensile strain rate of the outer layer 12 in the first stage. The axial tensile force on the axial deformation member 3 decreases compared to the axial tensile force on the axial deformation member 3 in the first stage. This results in a decrease in the axial tensile deformation of the radial deformation member 4 compared to the axial tensile deformation of the radial deformation member 4 in the first stage. The radial deformation member 4 undergoes radial expansion, causing the outer layer 12 of the anchor rod to re-compress the anchoring agent 2 and the inner core 11 of the rod. This results in a shear anchoring effect between the outer layer 12 of the anchor rod and the anchoring agent 2, and the anchoring force is transferred to the inner core 11 of the rod.

[0028] In addition, the anchoring structure also includes a tray and nut set at the end of the anchor rod 1, but the structure is no different from that of a traditional anchor rod 1.

[0029] Anchor 1 includes an inner core 11 and an outer layer 12. The inner core 11 can be stretched along the axial direction. The outer layer 12 is sleeved on the outside of the inner core 11 and connected to the anchoring agent 2. The outer layer 12 is provided with an axially expandable and contractible axial deformation member 3 and a radially deformable radial deformation member 4.

[0030] During the acceleration of axial tensile deformation of anchor rod 1, axial deformation component 3 undergoes accelerated tensile deformation along the axial direction, which in turn causes radial deformation component 4 to undergo axial tensile deformation and radial contraction deformation, thereby causing the outer layer 12 of the rod to separate from the anchoring agent 2 and reducing the force between the inner core 11 of the rod and the outer layer 12 of the rod. During the reduction of axial tensile deformation of anchor rod 1, the axial tensile deformation of radial deformation component 4 decreases and radial expansion deformation occurs, so that the outer layer 12 of the rod re-compresses the anchoring agent 2 and the inner core 11 of the rod, thereby enabling shear anchoring between the outer layer 12 of the rod and the anchoring agent 2 and transferring the anchoring force to the inner core 11 of the rod.

[0031] More specifically, in the initial installation state, the anchoring structure and the surrounding rock 5 are anchored by full-length bonding (locking or full-length friction). When the strain rate of the surrounding rock 5 in a certain area increases, the axial tensile deformation of the anchor rod 1 in that area accelerates, the core 11 of the rod is stretched, and at the same time, the axial deformation member 3 set in the outer layer 12 of the rod is stretched. More specifically, the axial deformation member 3 undergoes axial deformation, which in turn causes the radial deformation member 4 to undergo axial tension and radial contraction deformation, so that the outer layer 12 of the rod separates from the anchoring agent 2. That is, the locking between the anchoring structure and the surrounding rock 5 is released (or the mutual friction disappears), so that the anchoring structure set in this area changes from an anchored section to a free section, and stretches and deforms together with the surrounding rock 5. During this process, the anchoring structure maintains the axial tension of this section. As the strain rate of the surrounding rock 5 in this area decreases or becomes zero, the core 11 of the rod in the anchoring structure gradually stops stretching. Specifically, the axial tensile deformation of the radial deformation member 4 set in the outer layer 12 of the rod decreases and radial expansion occurs, so that the outer layer 12 of the rod re-adheres the anchoring agent 2, restoring the shear anchoring effect between the outer layer 12 of the rod and the anchoring agent 2. That is, the anchoring structure and the surrounding rock 5 are in contact again to form a support effect, restoring full-length anchoring, and enhancing the force between the core 11 of the rod and the outer layer 12 of the rod.

[0032] At the same time, because the axial deformation component 3 is similar to a viscoelastic material, its deformation has a time lag. Therefore, when the axial deformation of the anchor rod 1 decreases, the deformation of the axial deformation component 3 increases. When the force on the anchor rod 1 reaches a state of mechanical equilibrium, the axial deformation of the axial deformation component 3 stops.

[0033] In this way, the free section and the anchored section of the anchoring structure can be transformed into each other, so as to better control the stability and deformation of the surrounding rock.

[0034] In this scenario, it is assumed that the surrounding rock fractures at a certain point at time t=0, causing the axial strain rate of the anchorage structure at that location to... Because the outer layer 12 of the anchoring structure was in a state of stress relaxation before rapid fracture, The axial tensile force within the outer layer 12 of the rod is:

[0035] in, —Axial elastic stiffness coefficient of the outer layer 12 of the rod; —Axial viscosity coefficient of the outer layer 12 of the rod; —Effective cross-sectional area of ​​the outer layer 12 of the rod.

[0036] Specifically, the axial elastic stiffness coefficient and the axial viscosity coefficient of the outer layer 12 of the rod are determined based on the material, testing and design of the outer layer 12 of the rod.

[0037] Thus, by rationally designing the mechanical parameters of the outer layer 12 of the rod, it can exhibit differentiated mechanical responses under different axial strain rates. When the surrounding rock 5 undergoes rapid large deformation, the material stiffness increases, leading to a rapid increase in axial tensile force, which in turn triggers the action of the axial deformation element 3, causing the radial deformation element 4 to compress, causing the outer layer 12 of the rod to detach from the anchoring agent 2 and cutting off the shear force transmission path. Under slow deformation or static load, the tensile force increases gradually, without triggering the unloading mechanism, maintaining a normal anchoring state. This achieves intelligent control of the "presence" and "absence" of shear anchoring force, improving the adaptability and safety of the anchoring system under complex working conditions.

[0038] Based on the above formula, by adjusting the axial elastic stiffness coefficient, axial viscosity coefficient and effective cross-sectional area of ​​the outer layer 12 of the rod, or by utilizing the physical properties of the material itself (especially its sensitivity to deformation rate), the anchoring structure can achieve "intelligent discrimination" and "adaptive response" to the deformation of the surrounding rock.

[0039] In an optional embodiment, the radial deformation member 4 is connected to the axial deformation member 3 along the axial direction and is arranged alternately at equal intervals. The axial deformation member 3 is used to respond to the axial deformation of the surrounding rock 5, and the radial deformation member 4 generates radial deformation based on the deformation of the axial deformation member 3.

[0040] This configuration has two advantages: First, when the axial deformation component 3 is subjected to force and deforms, it directly pushes the adjacent radial deformation component 4 to undergo radial compression or expansion, thereby improving the response speed and transmission efficiency of the anchoring structure. Second, the radial and axial deformations are more uniform throughout the entire length of the anchoring structure, avoiding local stress concentration and preventing the anchoring agent 2 or the surrounding rock 5 from prematurely failing due to local compression.

[0041] It should be noted that the spacing between the alternating radial deformation element 4 and the axial deformation element 3 can also be different.

[0042] In another optional embodiment, the distribution of the axial deformation member 3 and the radial deformation member 4 depends on the actual situation. It can also be understood that the relative positions of the axial deformation member 3 and the radial deformation member 4 are arbitrary.

[0043] Along the axial direction, the distance between adjacent radial deformation elements 4 is equal; along the circumferential direction, the radial deformation elements 4 are evenly distributed.

[0044] This configuration serves two purposes: firstly, the equidistant arrangement of the radial deformation elements 4 ensures that the load is uniformly transmitted along the length of the anchoring structure, achieving axial force homogenization and avoiding local stress concentration; secondly, the circumferential uniform distribution of the radial deformation elements 4 ensures that the force acts symmetrically on the circumference when radial compression or expansion occurs, thereby preventing the anchoring structure from tilting, jamming, or being squeezed on one side by the anchoring agent 2, improving operational reliability, ensuring symmetrical radial response, preventing eccentric deformation or torsion, and extending the service life of the anchoring structure.

[0045] In another alternative embodiment, the distance between adjacent radial deformation members 4 may also be unequal, and the radial deformation members 4 may also be randomly distributed in the circumferential direction.

[0046] The radial deformation member 4 includes a top end that contacts the anchoring agent 2, a bottom end that contacts the inner core 11 of the rod, and a connecting part that connects the top end and the bottom end. The shape of the connecting part is arc-shaped, wavy, or zigzag-shaped, etc.

[0047] The radial deformation component 4 includes a shuttle-shaped steel clip 41, and the axial deformation component 3 includes carbon fiber resin 31. The carbon fiber resin 31 and the shuttle-shaped steel clip 41 are alternately distributed. It should be noted that the carbon fiber resin 31 and the shuttle-shaped steel clip 41 are alternately distributed in both the axial and radial directions and are closely connected in series.

[0048] Specifically, the outer corner of the shuttle-shaped steel clip 41 contacts the anchoring agent 2, and the inner corner of the shuttle-shaped steel clip 41 contacts the core 11 of the rod. The carbon fiber resin 31 and the shuttle-shaped steel clip 41 can be connected by, but are not limited to, adhesive bonding.

[0049] The shuttle-shaped steel clip 41 and the carbon fiber resin 31 have an arc-shaped contact to reduce sliding resistance, while the shuttle-shaped steel clip 41 and the anchoring agent 2 have a point contact, which makes it easy to detach and reset.

[0050] Carbon fiber resin 31 and shuttle-shaped steel clip 41 are alternately distributed along the axial direction to form a graded energy dissipation system, which avoids local stress concentration and improves overall durability.

[0051] It should be noted that in the axial force and deformation of the anchor rod 1, the shuttle-shaped steel clip 41 and the carbon fiber resin 31 are connected in series to form a Maxwell rheological model, and the viscosity coefficient of the carbon fiber resin 31 can be adjusted by adjusting the content of the material composition of the carbon fiber resin 31.

[0052] More specifically, the core 11 of the rod includes multiple steel fibers 111 and steel hoops 112, with the steel hoops 112 used to bind the multiple steel fibers 111. This can be understood as the steel fibers 111 being tightly compressed together, generating mutual friction and providing macroscopic support axial force. When the axial force is sufficiently large, the steel fibers 111 can undergo relative frictional movement over a certain distance, maintaining high deformation resistance, thereby achieving a high-resistance, large-deformation function.

[0053] When the strain rate decreases or approaches zero, the axial tension of the carbon fiber resin 31 gradually relaxes, the elastic deformation of the shuttle-shaped steel clip 41 recovers, and when the outer corner of the shuttle-shaped steel clip 41 squeezes the anchoring agent 2, it plays a role in forming an anti-shear anchoring effect between the anchor rod 1 and the anchoring agent 2; when the inner corner squeezes the core 11 of the rod, it plays a role in squeezing the steel fiber 111 bundle, increasing the tensile strength of the core 11 of the rod.

[0054] When the strain rate is high, the carbon fiber resin 31 exhibits significant viscosity, which leads to a large tensile stress in the axial direction of the shuttle-shaped steel clip 41. This causes the shuttle-shaped steel clip 41 to shrink radially, and the outer corner of the shuttle-shaped steel clip 41 to detach from the contact with the anchoring agent 2, forming a free section in the anchor rod 1. The compressive force of the inner corner on the inner core is also reduced, reducing the tensile strength of the inner core, making the free section more able to cope with the large deformation of the surrounding rock 5.

[0055] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0056] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0057] It should also be noted that in the apparatus, equipment, and housing of this application, the components or steps can be disassembled and / or reassembled. These disassemblies and / or reassemblies should be considered as equivalent solutions of this application.

[0058] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0059] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0060] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. An adaptive large deformation anchoring structure, characterized in that, include: Anchor bolts are used to provide anchoring support for the surrounding rock. When the anchor is installed in the surrounding rock, it is fully anchored to the surrounding rock. In the first stage when the surrounding rock undergoes axial deformation, the anchoring effect between at least one part of the anchor and the surrounding rock decreases until it is lost, and the at least one part changes from an anchored section to a free section. In the second stage when the surrounding rock undergoes axial deformation, the anchoring effect between the at least one part and the surrounding rock increases until it is restored, and the at least one part changes from a free section to an anchored section. This achieves the mutual transformation between the free section and the anchored section. In chronological order, the first stage precedes the second stage, and the axial strain rate of the anchor in the first stage is greater than that of the anchor in the second stage.

2. The adaptive large deformation anchoring structure according to claim 1, characterized in that, The anchor bolt includes an inner core and an outer layer. The inner core can be stretched axially, and the outer layer is sleeved on the outside of the inner core and connected to the anchoring agent. The outer layer is provided with an axially expandable and contractile axial deformation member and a radially deformable radial deformation member. In the first stage, the axial deformation member undergoes axial tensile deformation, which in turn causes the radial deformation member to undergo axial tensile deformation and radial contraction deformation, thereby separating the outer layer of the rod from the anchoring agent and reducing the force between the inner core of the rod and the outer layer of the rod. In the second stage, the axial tensile force on the axial deformation member is reduced compared to the axial tensile force on the axial deformation member in the first stage, resulting in a reduction in the axial tensile deformation of the radial deformation member compared to the axial tensile deformation of the radial deformation member in the first stage. Furthermore, the radial deformation member undergoes radial expansion, causing the outer layer of the rod to re-compress the anchoring agent and the inner core of the rod, thereby providing shear anchoring between the outer layer of the rod and the anchoring agent and transferring the anchoring force to the inner core of the rod.

3. The adaptive large deformation anchoring structure according to claim 2, characterized in that, The change in axial tensile force within the outer layer material of the rod is as follows: in, ; —The axial strain rate of the outer layer of the rod; —Axial strain of the outer layer of the rod; —The axial elastic stiffness coefficient of the outer layer of the rod; —The axial viscosity coefficient of the outer layer of the rod; —The effective cross-sectional area of ​​the outer layer of the rod.

4. The adaptive large deformation anchoring structure according to claim 2, characterized in that, Along the axial direction, the radial deformation member is connected to the axial deformation member and is arranged alternately at equal intervals.

5. The adaptive large deformation anchoring structure according to claim 4, characterized in that, Along the axial direction, the distance between adjacent radially deformable elements is equal; The radial deformation elements are uniformly distributed along the circumferential direction.

6. The adaptive large deformation anchoring structure according to claim 5, characterized in that, The radial deformation component includes a shuttle-shaped steel clip, and the axial deformation component includes carbon fiber resin. The carbon fiber resin and the shuttle-shaped steel clip are connected in series axially and are distributed alternately at equal intervals.

7. The adaptive large deformation anchoring structure according to claim 6, characterized in that, The core of the rod includes multiple steel fibers and steel hoops, the steel hoops being used to bind the multiple steel fibers.

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