Rockburst flexible protective net energy dissipation anchor rod device and construction method

Abstract

The invention belongs to the technical field of rockburst disaster prevention and control equipment, and particularly discloses a rockburst flexible protective net energy dissipation anchor rod device and a construction method.The energy dissipation anchor rod device comprises an anchor rod, a sleeve, a plugging base, a plugging cover and a first energy dissipation component, the anchor rod is of a hollow structure, and the hollow structure is used for grouting; the sleeve coaxially sleeves the anchor rod close to the outer side of the anchor hole, and the closed end of the sleeve is fixed on the side wall of the anchor rod; the plugging base sleeves the anchor rod and is located on the side, close to the sleeve, of the middle section of the anchor rod, and the section, located between the plugging base and the interior of the anchor hole, of the anchor rod forms an anchoring section; the plugging cover is fixedly connected with the anchor rod and the sleeve, and the plugging cover encloses the area between the anchor rod and the sleeve to form a containing cavity. The first energy dissipation component comprises a plurality of energy dissipation rods, a plurality of energy dissipation pieces and a mounting base. The energy dissipation anchor rod device provided by the invention is completely independent of a rock-soil body on the outer side of an anchor hole, can meet the dynamic deformation requirement of repeated rockburst for multiple times, and avoids the problem of'failure of energy dissipation after one-time rockburst '.

Description

Technical Field

[0001] This invention belongs to the technical field of rockburst disaster prevention equipment, and specifically relates to a rockburst flexible protective net energy dissipation anchor device and construction method. Background Technology

[0002] Rockburst is a geological disaster caused by the sudden release of elastic strain energy in a rock mass under high ground stress, resulting in rock fracturing, ejection, and a loud bang. Flexible rockburst protection netting systems are a crucial measure for preventing rockbursts. They are primarily used to intercept ejected rocks generated by rockbursts, protecting personnel and equipment and mitigating the hazards of rockbursts.

[0003] The rockburst flexible protection net system mainly consists of anchoring structures (anchor bolts / anchor cables), connecting structures (support ropes and connectors), and wire rope nets. Since rockbursts release huge amounts of energy, traditional rigid anchor bolts are not suitable for rockburst flexible protection net systems. As a result, energy dissipation anchor bolts have become the mainstream in rockburst flexible protection net systems.

[0004] The energy dissipation components or key structures of existing energy dissipation anchors are mostly concentrated on the soil and rock mass at the anchor hole. This arrangement and structural design cannot meet the requirements of rockburst environments. This is mainly because the soil and rock mass often undergoes repeated dynamic deformation under the action of rockburst. After the first rockburst, the soil and rock mass outside the anchor hole falls off, making it difficult for the energy dissipation components to exert force again. The existing energy dissipation anchors cannot adapt to this dynamic deformation requirement. After the energy dissipation components deform due to the first rockburst, they will be in an abnormal stress state for a long time, which will reduce the support stability of the soil and rock mass and cannot provide long-term reliable seismic energy dissipation support for geotechnical engineering.

[0005] For example, Chinese patent CN10863589A discloses a pressure-type shock absorption and energy dissipation prestressed anchor structure and construction method, which achieves energy dissipation by arranging elastic components between the inner baffle and the outer baffle. However, when the rock and soil at that location detaches due to a rock burst, at least one of the inner baffle and the outer baffle will lose the support of the rock and soil, which will cause one or both ends of the elastic component to lose effective support. When the rock and soil detaches again, it will not be able to provide effective energy dissipation. For example, Chinese patent CN22359818U discloses a fixing and energy dissipation anchor for a flexible protective net in a tunnel. It achieves energy dissipation by adding a spring between the second rope clamp and the first nut. However, after the first rock burst, the rock and soil at the outer end of the anchor hole detaches, and the end of the spring that contacts the second rope clamp loses the support of the rock and soil. When the rock and soil detaches again, it cannot provide effective energy dissipation. Moreover, the spring will deform after the first rock burst and will be in an abnormal stress state for a long time, which will reduce the support stability of the rock and soil and cannot provide long-term reliable seismic energy dissipation support for geotechnical engineering. Summary of the Invention

[0006] To address the aforementioned problems, the purpose of this invention is to provide a rockburst flexible protective net energy dissipation anchor device and its construction method.

[0007] The technical solution of the present invention is: a rockburst flexible protective net energy dissipation anchor device, comprising an anchor, a sleeve, a sealing base, a sealing cover, and a first energy dissipation component.

[0008] The anchor rod has a hollow structure for grouting. One end of the sleeve is closed, and the other end is open. The sleeve is coaxially fitted onto the anchor rod, and the closed end of the sleeve is fixed to the side wall of the anchor rod. A sealing base is fitted onto the anchor rod, located in the middle section near the sleeve. The section of the anchor rod between the sealing base and the anchor hole constitutes the anchoring section. Sealing caps are distributed at the ends of the anchor hole and are fixedly connected to both the anchor rod and the sleeve. The sealing caps enclose the area between the anchor rod and the sleeve to form a placement cavity. The first energy dissipation component includes multiple energy dissipation rods and multiple energy dissipation elements. The system includes components and an installation base. Multiple energy-dissipating rods are distributed circumferentially along the anchor rod axis. One end of each energy-dissipating rod is located inside the placement cavity, and a piston plate is installed at this end, which is slidably mounted on the side wall of the placement cavity. The other end of the energy-dissipating rod passes through the sealing cap. All energy-dissipating components are deformable structures, connected one-to-one with the piston plate. When the piston plate is displaced, it squeezes or stretches the energy-dissipating component, which dissipates energy through its own deformation. The installation base is fixed to the anchor rod. One side of the installation base is hinged to the other end of the energy-dissipating rod, and the other side is connected to the wire rope mesh through a connecting structure.

[0009] Furthermore, the ratio of the anchor bolt length to the anchoring section length is 1:(0.7~0.9).

[0010] Furthermore, multiple sets of arc plate groups are arranged circumferentially along the anchor rod axis inside the placement cavity. Each set of arc plate groups includes two relatively distributed arc plates. The two sides of the arc plates are fixed to the outer side wall of the anchor rod and the inner side wall of the sleeve, respectively. The arc plates, the outer side wall of the anchor rod, and the inner side wall of the sleeve form an installation cavity. The energy dissipation rod and the energy dissipation component are all located inside the installation cavity.

[0011] Furthermore, the first energy dissipation component also includes a first sealing tube seat, which is a tubular structure with a first external thread on its outer side wall and a first internal thread matching the first external thread on the inner side wall of the mounting cavity. The energy dissipation rod passes through the cavity of the first sealing tube seat.

[0012] Furthermore, the energy dissipation element is a first energy dissipation element, which is a mechanical elastic element. The first energy dissipation element is sleeved on the energy dissipation rod, with one end connected to the piston plate and the other end connected to the first sealing tube seat.

[0013] Furthermore, the energy dissipation element is a second energy dissipation element, which is a non-metallic elastic element, including a first elastic element and a second elastic element. The first elastic element is a solid columnar structure, with one end abutting against the inner side wall of the sleeve's closed end and the other end abutting against the piston plate. The second elastic element is a hollow structure, sleeved on the energy dissipation rod, with one end abutting against the piston plate and the other end abutting against the first sealing tube seat.

[0014] Furthermore, the anchor rod includes a first anchor rod and a second anchor rod. The first anchor rod has a hollow structure, with a grouting nozzle installed at one end inside the anchor hole, and a mounting base fixed to the other end of the first anchor rod. The second anchor rod is coaxially sleeved on the first anchor rod, and a sealing seat is installed inside the second anchor rod, through which the first anchor rod passes. The closed end of the sleeve is fixed to the second anchor rod, and the open end of the sleeve is flush with the end of the second anchor rod.

[0015] Furthermore, the first anchor rod includes a fixed section, a telescopic section, and a stretching section in sequence from inside the anchor hole to outside the anchor hole. The fixed section is fixed on the sealing seat, the stretching section is fixed on the mounting base, and a second energy dissipation component is provided between the outer side wall of the stretching section and the inner side wall of the second anchor rod.

[0016] Furthermore, the second energy dissipation component includes an anchor cup, an elastic clamp, a limiting block, and a second sealing tube seat. The anchor cup is movably sleeved on the outer wall of the extension section; the elastic clamp is movably sleeved on the outer wall of the extension section and located between the anchor cup and the extension section; the limiting block is fixed on the outer wall of the extension section, and the elastic clamp is located on the side away from the anchor cup; the second sealing tube seat is a tubular structure with a second external thread on its outer wall, and a second external thread matching the second external thread is provided on the inner wall of the second anchor rod. The first anchor rod passes through the cavity of the second sealing tube seat, and the second sealing tube seat abuts against the anchor cup.

[0017] A construction method based on the energy dissipation anchor device includes: drilling holes in the rock and soil to form anchor holes; placing anchor rods and sleeves into the anchor holes, ensuring that the sealing cap is tightly fitted to the rock and soil at the entrance of the anchor hole; grouting the anchor holes through the anchor rods to ensure that the anchoring agent evenly fills the gap between the anchor hole and the anchoring section without any voids; and fixing the wire rope mesh to the installation base after the anchoring agent has cured to the design strength.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The energy dissipation anchor device proposed in this invention constructs an independent energy dissipation system that does not rely on the rock and soil through a closed built-in design: the energy dissipation component and the energy dissipation rod are both placed in a closed placement cavity between the anchor rod and the sleeve. The placement cavity is formed by the sealing cover, the sleeve, and the anchor rod. The two end support points of the energy dissipation component fall on the closed end of the sleeve and the sealing cover, respectively, and are completely independent of the rock and soil outside the anchor hole. Even if the rock burst causes the rock and soil outside the anchor hole to fall off, the piston plate at the end of the energy dissipation rod can still slide smoothly along the side wall of the placement cavity, and the energy dissipation component is dissipated by squeezing / stretching. It can cope with the dynamic deformation requirements of repeated rock bursts and avoid the problem of "energy dissipation failure after one rock burst". Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a partial structural schematic diagram of Embodiment 1 of the present invention; Figure 3 This is a structural cross-sectional view of the arc plate assembly of the present invention; Figure 4 This is a partial exploded view of the present invention; Figure 5 This is an application diagram of the invention; Figure 6 This is a schematic diagram of the connection structure between the present invention and the wire rope mesh; Figure 7 This is a partial structural schematic diagram of Embodiment 2 of the present invention.

[0020] Among them, 1-anchor rod, 11-first anchor rod, 111-fixed section, 112-telescopic section, 113-stretching section, 12-second anchor rod, 120-sealing seat, 13-arc plate assembly, 130-arc plate, 2-sleeve, 3-sealing base, 4-sealing cover, 5-first energy dissipation component, 51-energy dissipation rod, 510-piston plate, 52-energy dissipation element, 520-first energy dissipation element, 521-first elastic element, 522-second elastic element, 53-installation base, 54-first sealing pipe seat, 6-second energy dissipation component, 61-anchor cup, 62-elastic clamp, 63-limiting block, 64-second sealing pipe seat. Detailed Implementation

[0021] The following is combined Figures 1 to 7The specific embodiments of the present invention will be described in detail below. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] Example 1 like Figure 1 , Figure 2 The rockburst flexible protective net energy dissipation anchor device shown includes an anchor 1, a sleeve 2, a sealing base 3, a sealing cover 4, and a first energy dissipation component 5.

[0024] Anchor rod 1 is inserted into the anchor hole. Anchor rod 1 has a hollow structure, which is used for grouting. Sleeve 2 is closed at one end and open at the other end. Sleeve 2 is coaxially fitted onto anchor rod 1, and the closed end of sleeve 2 is fixed to the side wall of anchor rod 1. Sealing base 3 is fitted onto anchor rod 1 and is located on the side of the middle section of anchor rod 1 near sleeve 2. The section of anchor rod 1 between sealing base 3 and the inside of anchor hole constitutes the anchoring section. Sealing cap 4 is distributed at the port of anchor hole and is fixedly connected to anchor rod 1 and sleeve 2. Sealing cap 4 encloses the area between anchor rod 1 and sleeve 2 to form a placement cavity. The first energy dissipation component 5 includes multiple energy dissipation rods 51, multiple energy dissipation elements 52, and mounting base 53. A set of energy dissipation rods 51 are distributed circumferentially along the axis of the anchor rod 1. One end of the energy dissipation rod 51 is located in the placement cavity, and a piston plate 510 is provided at this end, which is slidably mounted on the side wall of the placement cavity. The other end of the energy dissipation rod 51 passes through the sealing cover 4, and the sealing cover 4 is provided with a first through hole corresponding to the energy dissipation rod 51. Multiple energy dissipation components 52 are all deformable structures and are connected one-to-one with the piston plate 510. When the piston plate 510 is displaced, it squeezes or stretches the energy dissipation component 52, and the energy dissipation component 52 dissipates energy through its own deformation. The mounting base 53 is fixed on the anchor rod 1. One side of the mounting base 53 is hinged to the other end of the energy dissipation rod 51, and the other side is connected to the wire rope mesh through a connecting structure.

[0025] The energy dissipation anchor device proposed in this embodiment constructs an independent energy dissipation system that does not rely on the rock and soil through a closed internal design: the energy dissipation component 52 and the energy dissipation rod 51 are both placed in a closed placement cavity between the anchor rod 1 and the sleeve 2. The placement cavity is formed by the sealing cover 4, the sleeve 2, and the anchor rod 1. The two end support points of the energy dissipation component fall on the closed end of the sleeve 2 and the sealing cover 4, respectively, and are completely independent of the rock and soil outside the anchor hole. Even if the rock burst causes the rock and soil outside the anchor hole to fall off, the piston plate 510 at the end of the energy dissipation rod 51 can still slide smoothly along the side wall of the placement cavity, and the energy dissipation component 52 is compressed / stretched to dissipate energy. It can cope with the dynamic deformation requirements of repeated rock bursts and avoid the problem of "energy dissipation failure after one rock burst".

[0026] Multiple energy dissipation rods 51 are evenly distributed circumferentially along the axis of anchor rod 1, and each energy dissipation rod 51 corresponds to one energy dissipation component 52. After the rockburst impact load passes through the wire rope net → installation base 53 → energy dissipation rod 51, it can be synchronously distributed to all energy dissipation units, avoiding overload and breakage of a single energy dissipation component. The piston plate 510 at the end of the energy dissipation rod 51 slides with the side wall of the placement cavity to ensure that there is no jamming when the energy dissipation rod 51 is displaced, and the energy dissipation component 52 can fully deform, converting the instantaneous impact kinetic energy of the rockburst into deformation energy. Compared with the single-point energy dissipation structure, the energy dissipation efficiency is effectively improved.

[0027] The mounting base 53 and the energy dissipation rod 51 are connected by a hinge. When the rockburst impact direction deviates, the energy dissipation rod 51 can rotate adaptively around the hinge point to avoid component breakage caused by rigid force. At the same time, the energy dissipation component 52 is a deformable structure that can flexibly deform with the displacement of the piston plate 510 to adapt to the dynamic stress changes during rockburst. The anchoring section of the anchor rod 1 provides a stable foundation for the energy dissipation structure: the sealing base 3 is sleeved on the middle section of the anchor rod 1 and fits against the anchor hole port. After being fixed with the anchoring agent, it ensures that the anchor rod 1 will not loosen due to the tension / pressure during the energy dissipation process, realizing the synergy of "anchoring 1-energy dissipation 5" and avoiding anchoring failure during energy dissipation.

[0028] Preferably, the ratio of the length of the anchor bolt 1 to the length of the anchoring section is 1:(0.7~0.9).

[0029] By achieving a precise balance between "long anchorage section + reasonable external space", the device is provided with a strong pull-out resistance and stable energy transmission anchorage foundation, while also reserving sufficient installation and working space for the energy dissipation structure, thus achieving a deep synergy between "anchorage reliability" and "energy dissipation effectiveness".

[0030] The anchoring section accounts for 70% to 90% of the total length of the anchor rod 1, which can maximize the bonding strength between the anchor rod 1 and the anchor hole. The long anchoring section can form a larger contact area with the anchoring agent in the anchor hole. The anchoring agent can be resin mortar, cement grout, etc. In this embodiment, cement grout is used, which greatly enhances the bonding force between the anchor rod 1 and the rock mass. It can resist the instantaneous impact tensile force during rockburst and prevent the anchor rod 1 from being directly pulled out of the anchor hole, thus solving the problem of "anchoring failure" caused by the excessively short anchoring section in the prior art. The long anchoring section can gradually transfer the rockburst load borne by the energy dissipation structure from the anchor hole opening to the deep stable rock mass, avoiding the load being concentrated in the shallow part of the anchor hole, which would cause the rock mass of the hole wall to break, and further strengthening the overall support stability.

[0031] The outer side of the anchor rod 1 retains 10% to 30% of its length to precisely match the structural requirements of the device: this outer space can fully accommodate the sleeve 2, the placement cavity and the first energy dissipation component 5, ensuring that the piston plate 510 of the energy dissipation rod 51 has sufficient sliding stroke, and the energy dissipation component 52 can be fully squeezed / stretched to avoid limiting the energy dissipation efficiency due to insufficient space.

[0032] If the anchorage section accounts for less than 70%, the bond between the anchor rod 1 and the rock mass will be insufficient, and a chain reaction of "anchorage loosening - energy dissipation structure instability" may easily occur under rockburst impact. If the anchorage section accounts for more than 90%, the space outside the anchor rod 1 will be too narrow to accommodate the complete sleeve 2 and the first energy dissipation component 5, which will force the energy dissipation components to be simplified and ultimately reduce the energy dissipation efficiency.

[0033] Preferred, such as Figure 3 As shown, multiple sets of arc plate groups 13 are arranged circumferentially along the axis of the anchor rod 1 inside the placement cavity. Each set of arc plate groups 13 includes two relatively distributed arc plates 130. The two sides of the arc plates 130 are fixed to the outer side wall of the anchor rod 1 and the inner side wall of the sleeve 2, respectively. The arc plates 130, the outer side wall of the anchor rod 1, and the inner side wall of the sleeve 2 form an installation cavity. The energy dissipation rod 51 and the energy dissipation component 52 are both located inside the installation cavity.

[0034] The independent installation cavity formed by the arc plate 130, the outer wall of the anchor rod 1, and the inner wall of the sleeve 2 provides rigid constraints on the energy dissipation rod 51 and the energy dissipation component 52.

[0035] Displacement of energy dissipation components can be avoided: The dimensions of the installation cavity are precisely matched with the shape of the energy dissipation rod 51 and the energy dissipation component 52, which can limit the radial sway of the energy dissipation rod 51 and ensure that the energy dissipation rod is only subjected to axial force, avoiding uneven force and deformation failure of the energy dissipation component 52 due to radial displacement; The inner wall of the installation cavity is flat, which can form a stable sliding mating surface with the piston plate 510, reducing the frictional resistance and jamming risk when the piston plate slides, and ensuring that the energy dissipation component 52 can be fully deformed through "compression / stretching" to maximize energy dissipation efficiency.

[0036] Multiple sets of arc plate groups 13 are evenly distributed circumferentially along the axis of anchor rod 1, with each group corresponding to one energy dissipation unit, realizing "independent unit force bearing + overall coordinated energy dissipation": when the rockburst impact load is transmitted to the energy dissipation rod 51 through the installation base 53, the installation cavity can ensure that each energy dissipation unit only bears the load of its corresponding area, avoiding the mutual squeezing and collision of multiple energy dissipation rods 51 due to lack of separation, resulting in local stress concentration; the circumferentially even distribution of the arc plate group 13 corresponds one-to-one with the distribution of the energy dissipation rod 51, which can ensure the circumferential force balance of anchor rod 1, avoid the anchor rod 1 being subjected to lateral torque due to the offset of the energy dissipation unit, and prevent the anchoring section from loosening due to torque.

[0037] The installation cavity divides the placement cavity into multiple independent spaces, achieving dual protection of "unit isolation + impurity blocking": if the energy dissipation component 52 in a certain installation cavity breaks due to excessive deformation or the energy dissipation rod 51 is damaged, the independent installation cavity can prevent the fragments of the faulty component from entering other cavities, avoid affecting the normal operation of adjacent energy dissipation units, and reduce the risk of overall device failure.

[0038] Preferred, such as Figure 2 , Figure 4 As shown, the first energy dissipation component 5 also includes a first sealing tube seat 54. The first sealing tube seat 54 is a tubular structure with a first external thread on its outer side wall and a first internal thread matching the first external thread on the inner side wall of the mounting cavity. The energy dissipation rod 51 passes through the cavity of the first sealing tube seat 54.

[0039] The first sealing pipe seat 54, through its multi-functional design of "adjustable threaded fixing + energy dissipation support positioning", provides stable support and flexible adaptability for the energy dissipation component 5, solving the problems of difficult installation and positioning of the energy dissipation component 52, non-adjustable pre-tightening force, and complex subsequent maintenance, and further improving the reliability and practicality of the device.

[0040] The first sealing tube seat 54 is rigidly connected to the installation cavity via a threaded connection, providing stable axial positioning and radial constraint for the energy dissipation rod 51 and the energy dissipation component 52. One end of the energy dissipation component 52 needs to be connected to the fixed structure to achieve "compression / tension deformation". The first sealing tube seat 54 is fixed in the installation cavity via a thread, serving as a reliable support end for the energy dissipation component 52. It forms "two-end positioning" with the piston plate 510, preventing axial displacement or detachment of the energy dissipation component 52 during deformation and ensuring a stable energy dissipation path. The first sealing tube seat 54 is a tubular structure, with the energy dissipation rod 51 passing through its cavity. This restricts the radial sway of the energy dissipation rod 51. Combined with the constraint of the installation cavity and the piston plate 510, it ensures that the energy dissipation rod 51 slides only along the axial direction, avoiding uneven stress and local overload fracture of the energy dissipation component 52 due to radial offset.

[0041] The first external thread on the outer wall of the first sealing tube seat 54 matches the first external thread on the inner wall of the installation cavity. The position can be adjusted by rotation to achieve precise control of the pre-tightening force of the energy dissipation component 52. According to the frequency and impact intensity of rockbursts, the first sealing tube seat 54 can be rotated to move axially along the installation cavity. When rotating towards the piston plate 510, the energy dissipation component 52 can be pre-compressed to increase the initial pre-tightening force, which is suitable for high impact load scenarios. When rotating away from the piston plate 510, the pre-tightening force can be reduced to suit low impact load scenarios, which solves the problem of "fixed pre-tightening force and poor scenario adaptability" of existing energy dissipation structures. If there are slight errors in the length of the energy dissipation rod 51 and the size of the energy dissipation component 52 during installation, the error can be compensated by adjusting the position of the first sealing tube seat 54 to ensure that the energy dissipation component 52 is tightly fitted with the piston plate 510 and the first sealing tube seat 54, avoiding "empty stroke" caused by gaps.

[0042] Preferred, such as Figure 2 As shown, the energy dissipation element 52 is the second energy dissipation element, which is a non-metallic elastic element, including a first elastic element 521 and a second elastic element 522. The first elastic element 521 is a solid columnar structure, with one end abutting against the inner wall of the closed end of the sleeve 2 and the other end abutting against the piston plate 510. The second elastic element 522 is a hollow structure, sleeved on the energy dissipation rod 51, with one end abutting against the piston plate 510 and the other end abutting against the first sealing pipe seat 54. It should be noted that since the energy dissipation element 52 in this embodiment is a non-metallic elastic element, it is more suitable for construction in areas with weak to moderate rockbursts, such as shallow buried tunnels, rock slopes, and municipal underground engineering, with an impact load of 50kN / m. 2 ~150kN / m 2 Rock mass stress is 10MPa to 20MPa.

[0043] The first elastic element 521 and the second elastic element 522 form a "two-way / graded" energy dissipation system, which can cover different impact intensities of rockbursts and avoid the problem of "insufficient response to small impacts and failure of deformation in large impacts" of a single elastic element: When the rockburst impact load is small, the second elastic element 522, which has relatively flexible stiffness, first deforms to absorb energy, achieving "rapid buffering of light impacts"; if the impact load increases, after the second elastic element 522 deforms to its limit, the first elastic element 521, which has higher stiffness, begins to compress and deform, further absorbing large energy, forming a graded energy dissipation mode of "small impact - second elastic element 522 dominant, large impact - dual-element synergy", covering all scenarios from instantaneous small impacts to strong impacts. Whether the piston plate 510 moves towards the closed end of the sleeve 2 or towards the first sealing tube seat 54 after being impacted, the dual elastic elements can dissipate energy in synergy through "compression / tension deformation", avoiding the limitation of a single elastic element that can only dissipate energy in one direction, and adapting to the characteristics of the uncertain rockburst impact direction.

[0044] Non-metallic elastic components, such as rubber and polyurethane, are selected. In this embodiment, both the first elastic component 521 and the second elastic component 522 are made of rubber. This perfectly matches the "sealed and isolated, low-maintenance" working environment of the placement cavity, offering significant advantages over metallic elastic components. Non-metallic materials are not affected by moisture, rock debris, or dust that may remain in the placement cavity, eliminating concerns about rust and oxidation of metallic components. Furthermore, the low coefficient of friction on non-metallic surfaces results in less wear and tear from contact with the piston plate 510, the closed end of the sleeve 2, and the first sealing tube seat 54. Repeated deformation makes them less prone to "metal fatigue fracture," effectively extending their service life compared to metallic elastic components.

[0045] The second elastic element 522 is a hollow structure that can be directly sleeved on the outside of the energy dissipation rod 51. Utilizing the annular gap between the energy dissipation rod 51 and the installation cavity, no additional installation space is required, avoiding spatial conflicts with the first elastic element 521 and the piston plate 510. The first elastic element 521 is a solid column that precisely fills the axial gap between the "closed end of sleeve 2" and the "piston plate 510". If this gap is not utilized, it will lead to "empty stroke" in the initial stage of impact. It not only fills the spatial gap but also adds an extra layer of energy dissipation defense, achieving a dual optimization of "space utilization and energy dissipation performance".

[0046] In close coordination with the threaded adjustable design of the first sealing tube seat 54, the dual non-metallic elastic elements can precisely adapt to different preload requirements: when the first sealing tube seat 54 is rotated to adjust the preload, the second elastic element 522 can move with the sealing tube seat to achieve uniform compression, while the first elastic element 521 achieves preload through the slight displacement of the piston plate 510. The non-metallic elastic elements have good deformation recovery, and even if they are in a preloaded state for a long time, there will be no problem of "metal spring relaxation", ensuring long-term stability of the preload. For different rockburst risk areas, the dual elastic elements can be adjusted to be in the optimal preload state by adjusting the first sealing tube seat 54, ensuring that they can respond to impacts "instantly" in any scenario and avoiding energy dissipation lag or excessive deformation caused by improper preload.

[0047] Preferred, such as Figure 1 , Figure 2 As shown, the anchor rod 1 includes a first anchor rod 11 and a second anchor rod 12. The first anchor rod 11 has a hollow structure, and a grouting nozzle is provided at one end located in the anchor hole. The mounting base 53 is fixed to the other end of the first anchor rod 11. The second anchor rod 12 is coaxially sleeved on the first anchor rod 11. A sealing seat 120 is provided inside the second anchor rod 12, and the first anchor rod 11 passes through the sealing seat 120. The closed end of the sleeve 2 is fixed on the second anchor rod 12, and the open end of the sleeve 2 is flush with the end of the second anchor rod 12.

[0048] The first anchor rod 11 and the second anchor rod 12 are coaxially fitted together, and with the sealing seat 120 inside the second anchor rod 12, a clear division of labor is formed: "internal rod transmits force, external rod provides support". The first anchor rod 11 is connected at one end to the installation base 53, directly bearing the rockburst impact load transmitted from the wire rope net and transferring the load to the anchoring section and the energy dissipation structure. Its design, penetrating the sealing seat 120, ensures that the load can be directly transferred to the stable rock mass deep in the anchor hole, avoiding load loss in the middle section of the anchor rod. The second anchor rod 12 does not directly bear the impact load, but serves as the fixing foundation for the sleeve 2. The closed end of the sleeve 2 is fixed to the second anchor rod 12, and the sealing seat 120 separates the "anchoring section grouting area" from the "energy dissipation structure installation area"—the sealing seat 120 prevents grouting material from flowing into the interior of the second anchor rod 12, avoiding grout adhesion to the energy dissipation components and ensuring that the energy dissipation structure's movement is not disturbed.

[0049] Preferably, the first anchor rod 11 includes a fixed section 111, a telescopic section 112, and a stretching section 113 in sequence from inside the anchor hole to outside the anchor hole. The fixed section 111 is fixed on the sealing seat 120, and the stretching section 113 is fixed on the mounting base 53. A second energy dissipation component 6 is provided between the outer side wall of the stretching section 113 and the inner side wall of the second anchor rod 12.

[0050] The first anchor bolt 11 is divided into a fixed section 111, a telescopic section 112, and a tension section 113 in the direction from inside the anchor hole to outside the anchor hole. Each section has a specific function to ensure orderly load transfer and no local stress concentration. The fixed section 111 is directly fixed to the sealing seat 120 of the second anchor bolt 12, forming a "double fixation" together with the anchoring agent inside the anchor hole. It is rigidly connected to the second anchor bolt 12 through the sealing seat 120 and bonded to the rock mass through the anchoring agent, ensuring the absolute stability of the root of the first anchor bolt 11. It becomes a "stable starting point" for the transfer of impact loads and avoids overall instability caused by root loosening during load transfer. The telescopic section 112 is a deformable structure and can be made of corrugated material, elastic material, etc. In this embodiment, the telescopic section 112 is a corrugated section, located between the fixed section 111 and the tension section 113, which can undergo axial telescopic deformation during rockburst impact. When the impact load is transmitted from the extension section 113, the expansion section first uses its own deformation to "initially buffer" the load, preventing it from being directly and rigidly transmitted to the fixed section 111. This prevents the first anchor rod 11 from breaking due to the instantaneous strong impact, which is especially suitable for the "strong instantaneous explosive force" characteristic of rockbursts. One end of the extension section 113 is fixedly installed with the base 53, and the other end is connected to the expansion section 112. At the same time, a second energy dissipation component 6 is set between the outer wall and the inner wall of the second anchor rod 12. This component is responsible for transmitting the load to the expansion section 112 and the second energy dissipation component 6, and also serves as the load-bearing carrier of the second energy dissipation component 6, achieving a seamless connection between "load transmission and energy dissipation triggering" and preventing load loss or displacement during transmission.

[0051] When the rockburst impact intensity is relatively low, the outer first energy dissipation component 5, i.e., the energy dissipation rod 51, drives the piston plate 510 to compress / stretch the second energy dissipation component, dissipating energy through the deformation of the non-metallic elastic component. If the impact intensity increases, after the first energy dissipation component 5 reaches its deformation limit, the extension section 113 further displaces with the load, triggering the inner second energy dissipation component 6, which further absorbs energy through the friction and deformation of the elastic clip 62, forming a graded mode of "external energy dissipation - internal energy replenishment," avoiding the problem of "slow response to small impacts and inability to withstand large impacts" for a single energy dissipation component. Regardless of whether the impact load causes the mounting base 53 to contract into the anchor hole, the extension section 113 to move into the second anchor rod 12 and compress the second energy dissipation component 6, or to stretch outward from the anchor hole, causing the extension section 113 to drive the extension section 112 to extend, and the first energy dissipation component 5 to stretch and dissipate energy, both energy dissipation components can work together through "compression / stretching / friction" deformation, completely solving the limitation of "unidirectional energy dissipation" in traditional energy dissipation structures and adapting to the random characteristics of rockburst impact direction.

[0052] Preferred, such as Figure 2 As shown, the second energy dissipation component 6 includes an anchor cup 61, an elastic clamp 62, a limiting block 63, and a second sealing tube seat 64. The anchor cup 61 is movably sleeved on the outer wall of the extension section 113; the elastic clamp 62 is movably sleeved on the outer wall of the extension section 113 and is located between the anchor cup 61 and the extension section 113; the limiting block 63 is fixed on the outer wall of the extension section 113, and the elastic clamp 62 is located on the side away from the anchor cup 61; the second sealing tube seat 64 is a tubular structure with a second external thread on its outer wall, and a second external thread matching the second external thread is provided on the inner wall of the second anchor rod 12. The first anchor rod 11 passes through the cavity of the second sealing tube seat 64, and the second sealing tube seat 64 abuts against the anchor cup 61. This component, through its design of "dual energy dissipation of friction and deformation + adjustable threaded preload + precise limiting to prevent deviation + built-in protection and durability", forms a multi-level energy dissipation system with the first energy dissipation component 5, which solves the pain points of traditional energy dissipation components such as "single energy dissipation, fixed preload, and easy displacement failure". It is especially suitable for strong rockburst and repeated dynamic deformation scenarios.

[0053] The elastic clip 62 is movably fitted onto the outer wall of the extension section 113 and located between the anchor cup 61 and the limiting block 63. When a rockburst impact causes the extension section 113 to move into the anchor hole, the anchor cup 61 remains in position under the contact of the second sealing pipe seat 64. The elastic clip 62 is driven by the extension section 113 to generate sliding friction with the pipe wall, converting the impact kinetic energy into heat energy dissipation. The frictional resistance increases with the impact velocity, achieving a dynamic adaptation of "the stronger the impact, the more energy is dissipated by friction". The elastic clip 62 itself has elastic deformation capability - when the frictional resistance is insufficient to completely offset the impact, the elastic clip 62 will be squeezed by the anchor cup 61 and the limiting block 63 to undergo radial / axial deformation, further absorbing residual energy; and it can recover after deformation, avoiding metal fatigue fracture, adapting to the "multiple impacts" requirement of repeated rockbursts. The anchor cup 61 is movably fitted and abuts against the second sealing tube seat 64, which can not only evenly transmit the pre-tightening force of the second sealing tube seat 64 to the elastic clamp 62 to ensure the stability of the initial frictional resistance, but also limit the radial displacement of the elastic clamp 62 during impact, ensuring the smooth friction and deformation process and avoiding interruption of energy dissipation.

[0054] The second sealing tube seat 64, through the cooperation of the "second external thread + the inner wall thread of the second anchor rod 12", achieves flexible adjustment of the preload and energy dissipation threshold, solving the problem of "fixed preload and poor scene adaptability" of traditional energy dissipation components: rotating the second sealing tube seat 64 can move axially along the inner wall of the second anchor rod 12: when rotating towards the anchor cup 61, it will squeeze the anchor cup 61 and indirectly press the elastic clamp 62, increasing the initial friction between the elastic clamp 62 and the extension section 113, improving the energy dissipation threshold, and adapting to high ground stress and strong rockburst scenarios; when rotating away from the anchor cup 61, the preload decreases and the energy dissipation threshold decreases, adapting to low stress and weak rockburst scenarios, realizing "one component covering multiple scenarios". If the deformation of the extension section 112 of the first anchor rod 11 accumulates, or the elastic clamp 62 shows slight wear after long-term use, the preload can be supplemented by rotating the second sealing tube seat 64 to ensure that the elastic clamp 62 is always in close contact with the extension section 113, avoiding "empty stroke in the initial impact" due to gaps.

[0055] The fixed design of the limiting block 63, combined with the movable sleeve of the anchor cup 61 and the elastic clamp 62, forms a "fixed-moving" coordinated positioning system, ensuring that the components do not shift or the force is not disordered during energy dissipation. The limiting block 63 is fixed to the outer wall of the extension section 113 and is located on the side of the elastic clamp 62 away from the anchor cup 61. It can restrict the elastic clamp 62 from sliding axially along the extension section, ensuring that the elastic clamp 62 is always within the effective range of "anchor cup 61-limiting block 63", avoiding the elastic clamp 62 from shifting out of the working position due to impact, causing energy dissipation failure. Both the anchor cup 61 and the elastic clamp 62 are movably sleeved on the outer wall of the extension section 113 without rigid fixed constraints. When the extension section 113 moves axially, the elastic clamp 62 can slide smoothly with the extension section 113 to generate friction, and the anchor cup 61 can be finely adjusted in position according to the pre-tightening force of the second sealing pipe seat 64, avoiding "sliding jamming and local stress concentration" caused by rigid connection, ensuring the continuous and stable energy dissipation path.

[0056] The second energy dissipation component 6, acting as the "inner energy dissipation defense line," complements and coordinates with the outer first energy dissipation component 5, covering the full strength range from "weak impact to strong impact." When the impact load is small, only the outer first energy dissipation component 5 dissipates energy through the deformation of non-metallic elastic elements, while the second energy dissipation component 6 remains stable because it has not reached the pre-tightening threshold, avoiding excessive component wear caused by "small impact triggering strong energy dissipation." When the impact load exceeds the bearing limit of the first energy dissipation component 5, the extension section 113 drives the elastic clamp 62 to slide against the extension section 113, triggering the "friction-deformation" dual energy dissipation of the second energy dissipation component 6, further absorbing residual energy, preventing the impact load from being directly transmitted to the anchoring section and causing the anchor bolt 1 to fail, and significantly improving the device's ability to resist strong rockbursts.

[0057] A construction method utilizing the energy dissipation anchor device proposed in this embodiment includes: S1, Preprocessing Anchor holes are formed by drilling in the pre-anchoring area of ​​the soil and rock mass. The anchor hole consists of an inner section and an outer section. The diameter of the inner section is in the range of (1.4–2.1):1 of the diameter of the second anchor rod 12. The outer section is an enlarged version of the inner section, with its diameter being 1 cm–1.5 cm larger than the diameter of the sleeve 2. The total length of the inner and outer sections is 20 cm–50 cm longer than the total length of the second anchor rod 12.

[0058] After drilling is completed, use high-pressure airflow or clean water to clean the rock cuttings and dust inside the anchor hole to ensure that the hole wall is flat and free of impurities, so as to avoid affecting the bonding strength between the anchoring agent and the rock mass.

[0059] S2, Pre-commissioning of energy dissipation components Based on the estimated rockburst impact intensity of the construction area, rotate the first sealing pipe seat 54 to adjust the preload of the energy dissipation component 52—increase the preload in areas of strong impact and decrease the preload in areas of weak impact to ensure that the piston plate 510 and the energy dissipation component are tightly fitted without gaps. Rotate the second sealing pipe seat 64 to compress the anchor cup 61 and indirectly press the elastic clamp 62, setting the initial frictional resistance to adapt to the stress environment on site; check the fit between the elastic clamp 62 and the extension section 113 to prevent loosening.

[0060] S3, Implementation of Energy Dissipation Anchor Bolt Device Slowly insert the pre-tested energy dissipation anchor bolt 1 and sleeve 2 into the anchor hole, and ensure that the sealing cap 4 is tightly fitted with the soil and rock at the entrance of the anchor hole.

[0061] Anchoring agent is injected through the hollow channel of the first anchor rod 11. During the grouting process, the grouting nozzle at the end of the first anchor rod 11 is used to ensure that the anchoring agent fills the gap between the anchor hole and the anchoring section evenly without any voids.

[0062] After the anchoring agent has been cured to the design strength, the curing time is usually 24 to 48 hours, to ensure that the anchoring section forms a stable connection with the rock mass and the sealing base 3, and to prevent the anchor rod from loosening during the energy dissipation process.

[0063] It should be noted that the sealing base 3 is a columnar structure made of rubber. Its column radius corresponds to the diameter of the anchor hole. The side wall of the sealing base 3 has an annular groove. The annular groove and the inner wall of the anchor hole form a filling cavity. The filling cavity is filled with anchoring agent through the grouting pipe. The grouting pipe passes through the side wall of the annular groove of the sealing base 3, the sleeve 2, and the sealing cover 4 in sequence. The grouting pipe passes through the area between the two arc plate groups inside the sleeve 2.

[0064] S4. Connection and overall debugging of the protective netting The wire rope net is fixed to the mounting base 53 by means of bolts or other connection structures. During connection, it is ensured that the hinge point between the mounting base 53 and the energy dissipation rod 51 is flexible and without jamming, allowing the energy dissipation rod to rotate adaptively with the impact direction.

[0065] After installation, the steel wire rope net is manually pulled for pre-testing: check whether the energy dissipation rod 51 can drive the piston plate 510 to slide smoothly along the installation cavity, whether the second energy dissipation component can deform normally, and whether the elastic clip 62 of the second energy dissipation component 6 can generate effective frictional resistance.

[0066] Check all connection points to ensure there is no risk of loosening or falling off.

[0067] S5. Post-construction inspection Regular inspections during periods of high rockburst risk: Observe whether the sleeve 2 and the sealing cover 4 are deformed, whether the energy dissipation components have permanent deformation or breakage, and whether the connection between the wire rope net and the installation base 53 is firm.

[0068] Example 2 Unlike Example 2, the preferred embodiment is as follows: Figure 7 As shown, the energy dissipation element 52 is the first energy dissipation element 520, which is a mechanical elastic element. The first energy dissipation element 520 is sleeved on the energy dissipation rod 51, with one end connected to the piston plate 510 and the other end connected to the first sealing tube seat 54.

[0069] It should be noted that: In this embodiment, the first energy dissipation element 520 is specifically a cylindrical helical compression spring, which is made of 60Si2Mn, with an outer diameter of 10mm to 11mm, an inner diameter of 10.5mm to 11mm, a free length of 75mm, and an effective number of 6 to 8 coils.

[0070] Since this embodiment uses energy dissipation component 52 as a mechanical elastic component, it is suitable for areas with medium to strong rockbursts, such as deep-buried tunnels, metal mine shafts, and steep rock slopes, with an impact load of 100 kN / m. 2 ~300kN / m 2 Rock mass stress ≥ 20 MPa.

[0071] The stiffness of mechanical elastic components can be precisely customized through material selection and structural design, such as the spring steel type, spring wire diameter, and number of coils. Energy dissipation thresholds can be preset based on the rockburst impact intensity—for example, designing springs with corresponding stiffness for the estimated impact load in a specific area. This ensures that energy is absorbed precisely through "elastic deformation" during impact, avoiding both "insufficient stiffness leading to excessive deformation" and "excessive stiffness leading to insufficient energy dissipation." The energy dissipation accuracy is far higher than that of non-metallic elastic components with nonlinear deformation. Metallic mechanical elastic components have a long fatigue life; even after repeated deformation caused by rockburst impacts, they retain their elastic recovery ability, making them less prone to "permanent deformation and aging failure" like non-metallic components. Furthermore, mechanical elastic components have high overload resistance limits; under short-term strong impacts, they only undergo elastic deformation and do not fracture directly like non-metallic components, improving the reliability of the device against extreme impacts.

[0072] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and do not limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A rockburst flexible protective net energy dissipation anchor device, characterized in that, include: Anchor bolts are hollow structures used for grouting. A sleeve, closed at one end and open at the other, is coaxially fitted onto the anchor rod, with the closed end of the sleeve fixed to the side wall of the anchor rod. A sealing base is fitted onto the anchor rod and located on the side of the middle section of the anchor rod near the sleeve. The section of the anchor rod located between the sealing base and the inside of the anchor hole constitutes the anchoring section. The sealing caps are located at the ends of the anchor holes and are fixedly connected to the anchor rods and sleeves. The sealing caps enclose the area between the anchor rods and sleeves to form a placement cavity. The first energy dissipation component includes: multiple energy dissipation rods distributed circumferentially along the anchor rod axis, one end of each energy dissipation rod being located inside the placement cavity, with a piston plate slidably mounted on the side wall of the placement cavity; the other end of each energy dissipation rod penetrating the sealing cap; multiple energy dissipation elements, which are deformable structures, connected one-to-one with the piston plate; when the piston plate is displaced, it squeezes or stretches the energy dissipation elements, which dissipate energy through their own deformation; and a mounting base fixed to the anchor rod, one side of which is hinged to the other end of the energy dissipation rod, and the other side is connected to the wire rope mesh through a connecting structure.

2. The rockburst flexible protective net energy dissipation anchor device as described in claim 1, characterized in that, The ratio of the length of the anchor bolt to the length of the anchoring section is 1:(0.7 to 0.9).

3. The rockburst flexible protective net energy dissipation anchor device as described in claim 1, characterized in that, Multiple sets of arc plate groups are arranged circumferentially along the anchor rod axis inside the placement cavity. Each set of arc plate groups includes two relatively distributed arc plates. The two sides of the arc plates are fixed to the outer side wall of the anchor rod and the inner side wall of the sleeve, respectively. The arc plates, the outer side wall of the anchor rod, and the inner side wall of the sleeve form an installation cavity. The energy dissipation rod and energy dissipation component are all located inside the installation cavity.

4. The rockburst flexible protective net energy dissipation anchor device as described in claim 3, characterized in that, The first energy dissipation component also includes a first sealing tube seat, which is a tubular structure with a first external thread on its outer side wall and a first internal thread matching the first external thread on the inner side wall of the mounting cavity. The energy dissipation rod passes through the cavity of the first sealing tube seat.

5. The rockburst flexible protective net energy dissipation anchor device as described in claim 4, characterized in that, The energy dissipation element is the first energy dissipation element, which is a mechanical elastic element. The first energy dissipation element is sleeved on the energy dissipation rod, with one end connected to the piston plate and the other end connected to the first sealing tube seat.

6. The rockburst flexible protective net energy dissipation anchor device as described in claim 4, characterized in that, The energy dissipation element is a second energy dissipation element, which is a non-metallic elastic element, including: The first elastic element is a solid columnar structure, with one end abutting against the inner wall of the closed end of the sleeve, and the other end abutting against the piston plate; The second elastic element is a hollow structure, sleeved on the energy dissipation rod, with one end in contact with the piston plate and the other end in contact with the first sealing tube seat.

7. The rockburst flexible protective net energy dissipation anchor device as described in claim 1, characterized in that, The anchor bolt includes: The first anchor rod is a hollow structure with a grouting nozzle at one end inside the anchor hole, and the mounting base is fixed to the other end of the first anchor rod. The second anchor rod is coaxially sleeved on the first anchor rod, and a sealing seat is installed inside the second anchor rod, through which the first anchor rod passes; the closed end of the sleeve is fixed on the second anchor rod, and the open end of the sleeve is flush with the end of the second anchor rod.

8. The rockburst flexible protective net energy dissipation anchor device as described in claim 7, characterized in that, The first anchor rod includes a fixed section, a telescopic section and a stretching section in sequence from the inside of the anchor hole to the outside of the anchor hole. The fixed section is fixed on the sealing seat, the stretching section is fixed on the mounting base, and a second energy dissipation component is provided between the outer side wall of the stretching section and the inner side wall of the second anchor rod.

9. The rockburst flexible protective net energy dissipation anchor device as described in claim 8, characterized in that, The second energy dissipation component includes: Anchor cups are movably fitted onto the outer wall of the stretching section; The elastic clip is movably sleeved on the outer wall of the stretching section, located between the anchor cup and the stretching section; The limiting block is fixed on the outer wall of the extension section, and the elastic clip is located on the side away from the anchor cup; The second sealing tube seat is a tubular structure with a second external thread on its outer side wall. The inner side wall of the second anchor rod is provided with a second external thread that matches the second external thread. The first anchor rod passes through the cavity of the second sealing tube seat, and the second sealing tube seat abuts against the anchor cup.

10. A construction method, characterized in that, Based on the energy dissipation anchor device according to any one of claims 1-9, the construction method includes: Drill holes in the rock and soil to form anchor holes; place anchor rods and sleeves into the anchor holes, and ensure that the sealing cap is tightly fitted to the rock and soil at the entrance of the anchor hole; Grouting is performed in the anchor hole by anchor bolts to ensure that the anchoring agent fills the gap between the anchor hole and the anchoring section evenly and without any voids. After the anchoring agent has cured to the designed strength, fix the wire rope net to the installation base.

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