Anchor-net coupled energy-absorbing support system for underground engineering

Abstract

The present invention belongs to the technical field of underground engineering support, and specifically discloses an underground engineering anchor net coupling energy absorption support system, including: a plurality of butterfly-shaped flexible connection nodes arranged on the support net, the butterfly-shaped flexible connection nodes include a breakable energy absorption structure arranged at the center position, and a plurality of flexible energy absorption connection structures arranged on the periphery of the breakable energy absorption structure; a plurality of ring-shaped nodes arranged on the support net, the ring-shaped nodes are arranged at the tray installation position, the anchor rods or anchor cables pass through the ring-shaped nodes, and are fixed by a rotating coupling energy absorption device; and / or, the ring-shaped nodes are arranged at the overlapping position of two support nets, and the two support nets are connected by an embedded mesh connection device. The various support components of the present invention are coupled with each other and jointly supported to form an underground engineering anchor net coupling energy absorption support system, which can give full play to the energy efficiency of each support component and realize efficient coupling energy absorption support.

Description

Technical Field

[0001] The invention relates to the technical field of underground engineering support, and in particular to an underground engineering anchor-net coupled energy-absorbing support system. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] The anchor net support system, which is composed of support nets, anchor rods (or anchor cables), trays and other components, is the main form of support for deep mine tunnels. As underground projects develop deeper, surrounding rock support faces challenges such as high stress, strong disturbance, and extremely soft rock. Dynamic disasters in deep tunnels occur frequently. The coupling performance between the components of the traditional anchor net support system is poor. For example, the support nets and anchor rods (or anchor cables) are often damaged by the shearing action of the tray due to deformation, and the support advantages of each component cannot be effectively exerted, resulting in the failure of the support system. At the same time, the energy absorption performance of the support components needs to be further improved to cope with dynamic disasters in deep projects. Therefore, it is crucial to improve the coupling effect of anchor net support and improve the support system of underground projects.

[0004] The traditional anchor net support system for underground engineering has the following main shortcomings:

[0005] ① The traditional cross-shaped welded support mesh has high rigidity and good surrounding rock support control effect, but its deformation effect is poor. When the surrounding rock undergoes large deformation, the welded support mesh often breaks due to its poor deformation capacity, resulting in failure of surrounding rock support.

[0006] ② The traditional diamond support net has a large deformation capacity and a good effect on controlling the large deformation of the tunnel surrounding rock. However, the diamond net has poor rigidity and is easy to form net bags, causing the roof to sink beyond the allowable support range, affecting the transportation and ventilation safety of the tunnel space.

[0007] ③ The traditional pallet structure has a single function, and the anchor rod prestress is only applied within a small range of the support net, and the pallet boundary is not chamfered. When the support net, anchor rod (or anchor cable) and other support components are greatly deformed, shear failure is likely to occur at the contact point of the pallet, resulting in failure of the support system.

[0008] ④ The traditional tray is in linear contact with the support net. The prestress of the anchor rod is transferred to the support net through the tray, and then transferred to the surrounding rock surface by the support net. The support net and the surrounding rock are also in linear contact, which causes the prestress to be transferred only within a very small range of the surrounding rock and easily crush the surrounding rock surface, affecting the control effect of the anchor rod (or anchor cable) prestress on the surrounding rock.

[0009] ⑤ The traditional pallet is small in size and the mesh holes of the steel mesh are large. The number of mesh wires directly under the anchor pallet is small. At the construction site, once the mesh wires of the anchor pallet are broken, the bearing capacity of the support system will drop rapidly.

[0010] ⑥ The coupling effect between traditional pallets and anchor rods (or anchor cables) is poor. The stress in underground projects is often more complicated. The anchor rods (or anchor cables) are subject to the combined effects of tension, shear, torsion and other forces. The anchor rods (or anchor cables) are prone to twisting and bending. The contact points between the anchor rods (or anchor cables) and the pallets cannot deform in coordination, which easily leads to stress concentration and shear breakage of the anchor rods (or anchor cables).

[0011] ⑦ The connection method between the traditional support net meshes is mostly wire binding. The wire binding causes the force transmission effect of the support net to deteriorate, and the wire binding is prone to breakage, making the mesh connection a weak link in the support system.

[0012] ⑧ The traditional anchor mesh support system mainly considers the strength and bearing performance of a single component, but pays little attention to the joint support capacity and coupling support effect of each component, and is unable to give full play to the support efficiency of each support component itself. Summary of the invention

[0013] In order to solve the above problems, the present invention proposes an underground engineering anchor net coupled energy absorption support system, which can improve the coupling effect of each support component, reduce the weak links of the support system, maximize the support capacity of each component, absorb pressure and control deformation, so as to more effectively deal with deep engineering disasters.

[0014] In some embodiments, the following technical solutions are adopted:

[0015] An underground engineering anchor-net coupled energy-absorbing support system, comprising:

[0016] A plurality of butterfly-shaped flexible connection nodes are arranged on the support net, wherein the butterfly-shaped flexible connection nodes include a breakable energy absorbing structure arranged at a central position, and a plurality of flexible energy absorbing connection structures arranged at the periphery of the breakable energy absorbing structure, and each of the flexible energy absorbing connection structures is sleeved with a constant resistance energy absorbing unit on the outside. When the butterfly-shaped flexible connection node is compressed and deformed, the breakable energy absorbing structure bears the pressure first, and after the breakable energy absorbing structure is broken under pressure, the flexible energy absorbing connection structure is compressed and deformed, and the pressure is absorbed by the constant resistance energy absorbing unit.

[0017] A plurality of annular nodes arranged on the support net, wherein the annular nodes are arranged at the tray installation location, the anchor rods or anchor cables pass through the annular nodes, and are fixed by a rotating coupling energy absorbing device, wherein the rotating coupling energy absorbing device is used to absorb the prestress of the anchor rods or anchor cables and directly transfer the prestress of the anchor rods or anchor cables to the surrounding rock surface;

[0018] And / or, the ring-shaped node is arranged at the overlapping position of two support nets, and the two support nets are connected by an embedded mesh connecting device.

[0019] As a further solution, the constant resistance energy absorption unit comprises: a resistance sleeve sleeved on the outside of the flexible energy absorption connection structure, the end of the resistance sleeve is open, a sliding plug body is arranged in the opening, a connecting piece is arranged at the bottom of the sliding plug body, and the top of the flexible energy absorption connection structure is connected to the connecting piece;

[0020] After the breakable energy-absorbing structure breaks under pressure, the flexible energy-absorbing connection structure is stretched toward the outside of the resistance sleeve under pressure, driving the sliding plug to move from the end of the resistance sleeve to the opposite end, thereby achieving constant resistance pressure-releasing energy absorption.

[0021] As a further solution, the connecting member includes: two force transmission rods arranged opposite to each other, one end of the two force transmission rods is respectively connected to the bottom of the sliding plug body, and the other end is connected together through a support rod; a connecting rod is also provided between the two force transmission rods, and the top end of the flexible energy absorption connection structure is connected to the connecting rod;

[0022] The connecting rod is buckled together by a first connecting unit and a second connecting unit, and the first connecting unit and the second connecting unit are disconnected when the pulling force of the two force transmission rods is lost.

[0023] As a further solution, it also includes: a pressure-releasing energy absorption warning device, the pressure-releasing energy absorption warning device includes:

[0024] The first stress monitoring element is used to monitor the pressure of the connector on the bottom of the resistance casing. When the first stress monitoring element detects that the pressure of the connector on the bottom of the resistance casing reaches the set first safety load, an alarm is triggered; the first safety load is specifically: F a =λ*F1, λ is the safety load coefficient of the support net, and F1 is the maximum bearing capacity of the support net.

[0025] As a further solution, the breakable energy absorption structure is a cross-shaped connection structure, which connects the four connection ends at the cross-intersection position of the support net; a flexible energy absorption connection structure is connected between two adjacent ends; the flexible energy absorption connection structure is an arc-shaped flexible steel sheet, and the two ends of the steel sheet are respectively connected to the two ends of the cross-shaped connection structure.

[0026] As a further solution, the embedded mesh connection device includes a first plug-in block and a second plug-in block, and the first plug-in block and the second plug-in block can be respectively inserted into the ring node and connected together by threads.

[0027] As a further solution, the rotating coupling energy absorption device includes: a main tray, a prestressed force transmission sleeve, a pressure-release angle adjustment structure and an angle adjustment wedge; an annular groove adapted to the annular node is provided on the side of the main tray close to the support net, and the annular node can be embedded in the annular groove; a spherical angle adjustment wedge is provided at the center of the main tray, and the spherical angle adjustment wedge can rotate in the disc; the prestressed force transmission sleeve is provided on the side of the main tray away from the support net, a bearing platform is provided in the prestressed force transmission sleeve, a flat force transmission disc is provided on the bearing platform, and a hollow pressure-release angle adjustment structure is provided between the flat force transmission disc and the main tray;

[0028] The main body tray, the pressure-adjusting angle structure, the flat force transmission plate and the spherical angle-adjusting wedge are all provided with through holes for the anchor rods or anchor cables to pass through.

[0029] As a further solution, the upper surface of the flat force transfer plate is provided with an arc-shaped groove adapted to the hemispherical prestressed nut; a through hole larger than the diameter of the anchor rod or anchor cable is reserved in the middle of the flat force transfer plate, and the through hole is inclined at a set angle to adapt to the torsion of the anchor rod or anchor cable after being subjected to force.

[0030] As a further solution, the main body tray is disc-shaped, including an inner ring part and an outer ring part, the outer ring part is bent outward at a set angle to form a reverse bend structure to fit the support net; the outermost extension is an arc structure to avoid shear damage to the support net; the inner ring part is provided with an annular groove, and the annular node area of ​​the support net is embedded in the annular groove; the inner ring part directly contacts the surface of the surrounding rock to directly transfer the prestress applied by the anchor rod or anchor cable to the surrounding rock.

[0031] As a further solution, it also includes: a coupling energy absorption warning device, the coupling energy absorption warning device includes:

[0032] The second stress monitoring element is used to monitor the prestress of the anchor rod or anchor cable. When the stress detected by the second stress monitoring element exceeds the second safety load, an alarm is triggered; the second safety load is specifically designed as: F b =μ*F2, μ is the safety load factor, and F2 is the maximum bearing capacity of the anchor rod or anchor cable.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The support net of the present invention is provided with a set number of butterfly-shaped flexible connection nodes, which cooperate with the constant resistance energy absorption unit. When the butterfly-shaped node is deformed, it drives the sliding plug in the resistance casing to move in the resistance casing, and realizes the constant resistance pressure-absorbing energy of the butterfly-shaped node through the deformation of the resistance casing and the friction force. It ensures that the support net can fully exert its deformation capacity when subjected to complex surrounding rock stress conditions, and retains the strength of the support net, so as to achieve the effect of flexible pressure-absorbing deformation.

[0035] (2) A set number of ring nodes are provided on the support net of the present invention. The support nets at overlapping positions are connected by the cooperation of the embedded mesh connecting device and the ring nodes, which can stably connect the two support nets to improve the phenomenon that the mesh connection is easy to break.

[0036] (3) The present invention fully utilizes the support capacity of each support component through the coupling effect of the rotating coupling energy absorption device and the support net, anchor rod or anchor cable. The annular steel sheet area of ​​the annular node of the support net is embedded through the annular groove at the bottom of the tray. The inner circle of the tray directly contacts the surface of the surrounding rock, and the contact area between the tray and the support net and the number of mesh wires at the bottom of the tray are increased. The prestress applied by the anchor rod is directly transferred to the surrounding rock, avoiding the transmission of prestress through the support net. The transmission of prestress is transformed from line contact between the surrounding rock and the support net to surface contact between the surrounding rock and the tray, and at the same time, the shear resistance and anti-slip ability of the support net at the tray are improved.

[0037] (4) The present invention uses a rotational coupling energy absorption device and performs a reverse bending treatment on the outer ring of the main tray to ensure that the tray further fits the surrounding support net when the surrounding rock deformation causes the support net to deform and twist. The outermost extension of the disk is an arc structure to prevent the support net from being sheared and damaged by the edge of the tray after being deformed and twisted. At the same time, the angle adjustment wedge, the pressure adjustment angle structure and the hemispherical nut inside the tray structure cooperate to ensure that the anchor rod or anchor cable passes through the inside of the tray to avoid the shear stress of the tray structure due to tilting and rotation.

[0038] (5) The present invention realizes pressure-absorbing energy of the support net by setting butterfly-shaped flexible connection nodes on the support net in combination with a breakable energy absorption structure and a constant resistance energy absorption unit; realizes absorption and transmission of prestress of anchor rods or anchor cables by cooperation of ring-shaped nodes and a rotating coupling energy absorption device, and can directly transfer the prestress of anchor rods or anchor cables to the surface of the surrounding rock; ensures stable connection between two support nets by ring-shaped nodes and embedded mesh connection devices; and each support component is coupled and jointly supported to form an underground engineering anchor net coupled energy absorption support system, which can give full play to the energy efficiency of each support component and realize efficient coupled energy absorption support.

[0039] Other features and advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall structure of the support net in an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of a butterfly-shaped flexible connection node structure in an embodiment of the present invention;

[0042] Figure 3A schematic diagram of a ring node structure in an embodiment of the present invention;

[0043] Figure 4 It is a schematic diagram of the connection between the constant resistance energy absorption unit and the butterfly-shaped flexible connection node in an embodiment of the present invention;

[0044] Figure 5 It is a cross-sectional view of the structure of the constant resistance energy absorption unit in an embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram of the structure of the constant resistance energy absorption unit connecting piece in an embodiment of the present invention;

[0046] Figure 7 This is a schematic diagram of the connecting rod structure in an embodiment of the present invention;

[0047] Figure 8 This is a schematic diagram of the structure of an embedded mesh connection device in an embodiment of the present invention;

[0048] Fig. 9 This is a schematic structural diagram of a rotational coupling energy absorption device in an embodiment of the present invention;

[0049] Fig.10 This is a schematic diagram of the surface structure of the main tray in an embodiment of the present invention;

[0050] Among them, 1. Support net, 11. Arc-shaped flexible steel sheet, 12. Cross-shaped connection structure, 13. Ring node; 2. Constant resistance energy absorption unit, 21. Resistance sleeve, 22. Sliding plug, 23. Connecting rod, 24. Force transmission rod, 25. Support rod, 26. Bottom top block; 3. Embedded mesh connection device, 31. First plug block, 32. Thread, 33. Second plug block; 4. Rotational coupling energy absorption device, 41. Main tray, 42. Angle adjustment wedge, 43. Reverse bending structure, 44. Inner ring of main tray, 45. Annular groove, 46. Force transmission sleeve, 47. Bearing platform, 48. Position adjustment groove, 49. Bottom platform of force transmission sleeve, 410. Prestressed nut, 411. Arc-shaped groove, 412. Flat force transmission plate, 413. Pressure adjustment angle structure, 414. Anchor rod or anchor cable. DETAILED DESCRIPTION

[0051] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0052] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0053] Embodiment 1

[0054] In one or more embodiments, an underground engineering anchor net coupled energy absorption support system is disclosed, which realizes pressure-releasing energy absorption of the support net through butterfly-shaped flexible connection nodes arranged on the support net, in cooperation with a breakable energy absorption structure and a constant resistance energy absorption unit; realizes absorption and transfer of prestressed anchor rods or anchor cables through the cooperation of ring-type nodes and rotating coupling energy absorption devices, and can directly transfer the prestressed anchor rods or anchor cables to the surrounding rock surface; ensures stable connection between two support nets through ring-type nodes and embedded mesh connection devices; and each support component is coupled and jointly supported to form an underground engineering anchor net coupled energy absorption support system, which can give full play to the energy efficiency of each support component and realize efficient coupled energy absorption support.

[0055] As a specific implementation method, Figure 1 The various structures of the underground engineering anchor net coupled energy absorption support system specifically include:

[0056] Support net 1, the support net is provided with a set number of butterfly-shaped flexible connection nodes; combined with Figure 2 In this embodiment, the butterfly-shaped flexible connection node includes a breakable energy absorbing structure arranged at a central position and a plurality of flexible energy absorbing connection structures arranged at the periphery of the breakable energy absorbing structure.

[0057] Specifically, the breakable energy absorption structure is a cross-shaped connection structure 12, which connects the four connection ends at the cross-intersection position of the support net; the flexible energy absorption connection structure is an arc-shaped flexible steel sheet 11, and an arc-shaped flexible steel sheet 11 is connected between each two adjacent ends to form a butterfly shape.

[0058] Combination Figure 4 and Figure 5 A constant resistance energy absorption unit 2 is sleeved on the outside of each flexible steel sheet connection structure, and the constant resistance energy absorption unit 2 includes: a resistance sleeve 21 sleeved on the outside of the flexible steel sheet connection structure, the end of the resistance sleeve is open, a sliding plug body 22 is arranged in the opening, a connecting piece is arranged at the bottom of the sliding plug body 22, and the top of the flexible steel sheet connection structure is connected to the connecting piece; bottom top blocks 26 are respectively arranged at both ends of the bottom of the resistance sleeve.

[0059] In the butterfly-shaped flexible connection node of the present embodiment, the cross-shaped connection structure is a primary node, and the flexible steel sheet connection structure and the constant resistance energy absorption unit constitute a secondary node; when the support net is subjected to deformation pressure from the tunnel wall and the top plate, the butterfly-shaped flexible connection node is compressed and deformed, and the primary node is first subjected to pressure. After exceeding the rated tensile force, the primary node absorbs energy and breaks, and the cross-shaped support net extends and deforms along the force direction, so that the flexible steel sheet connection structure is deformed by force to form a secondary node. The flexible steel sheet connection structure is compressed and stretched toward the outside of the resistance casing, driving the sliding plug to move from the end of the resistance casing to the opposite end, realizing constant resistance pressure absorption; finally, the flexible steel sheet connection structure is separated from the connecting piece, and the flexible steel sheet connection structure is completely pulled out, and the flexible steel sheet connection structure is stretched from a curved type to a straight type.

[0060] The above deformation process will ensure that the support net produces a certain amount of deformation, which will play the role of absorbing and allowing pressure. After the deformation is completed, the welded net will play its characteristics of high strength, high rigidity and small deformation, stably support the deformed rock mass and prevent the tunnel from falling and collapsing due to further large deformation of the tunnel.

[0061] As a specific example, combining Figure 6 The connecting member of this embodiment specifically includes: two force transmission rods 24 arranged opposite to each other at the bottom of the sliding plug body, one end of the two force transmission rods 24 is respectively connected to the bottom of the sliding plug body, and the other end is connected together through a support rod 25; a connecting rod 23 is also provided between the two force transmission rods 24, and the connecting rod 23 is located between the support rod 25 and the sliding plug body 22, and the top end of the flexible steel sheet connection structure is connected to the connecting rod 23.

[0062] The two ends of the support rod 25 are respectively connected to the two force transmission rods 24. The support rod and the force transmission rod can be bonded together or connected by a thin rod to play a stabilizing role. The strength of the connection is relatively low, ensuring that when the sliding plug slides down to the bottom, the connection can be easily broken when the support rod contacts the bottom top block; after breaking, as the plug continues to slide down, the bottom top block can lift up the entire support rod, so that the support rod falls off directly, and then there is no support rod in the middle of the force transmission rod to support it, and it will move closer to the middle.

[0063] Combination Figure 7The connecting rod is buckled together by the first connecting unit and the second connecting unit. When the support rod 25 supports the two force transmission rods 24, the connecting rod 23 remains rigid due to the tension on both sides; when the butterfly-shaped flexible connection node is compressed and deformed, the flexible steel sheet connection structure drives the sliding plug body to move in the resistance sleeve through the connecting rod until the sliding plug body moves to the bottom end of the resistance sleeve, and the bottom top block 26 of the resistance sleeve pushes the support rod upward. After reaching the safety load setting value, the support rod falls off. At this time, the connecting rod loses the tension on both sides, and the middle part of the connecting rod will be disconnected. The flexible steel sheet connection structure slides out from the notch in the middle of the connecting rod, thereby detaching from the resistance sleeve, achieving constant resistance pressure absorption.

[0064] Combination Figure 3 In this embodiment, a set number of ring nodes 13 are also provided on the support net; the ring nodes 13 can be set as needed in the prestressing area of ​​the anchor rod or anchor cable (i.e., the tray installation location), as well as the key node positions where the support mesh boundaries overlap, and can be combined with the rotational coupling energy absorption device and the embedded mesh connection device for support.

[0065] Specifically, as an implementation method, the two support nets can be connected at the overlapping ring node positions through an embedded mesh connection device. Figure 8 The embedded mesh connection device includes a first plug-in block 31 and a second plug-in block 33. The first plug-in block 31 and the second plug-in block 33 are both cylindrical structures connected to a circular cover plate. The size of the cylinder is slightly smaller than the inner circle of the ring-type node of the support net, and the circular cover plate is slightly larger than the outer circle of the ring-type node of the support net; the inner wall of the cylinder of the first plug-in block is provided with a thread 32, and the outer wall of the cylinder of the second plug-in block is provided with a thread. The first plug-in block and the second plug-in block can be respectively inserted into the ring-type node and connected together by threads.

[0066] At the connection of the two support nets, the two support nets can be partially overlapped, the ring nodes of the two support nets can be aligned, and then the first plug block and the second plug block can be inserted therein and threadedly tightened. The overlapping ring nodes can be fastened through the embedded mesh connecting device, which can stably connect the two support nets and improve the phenomenon of easy breakage at the mesh connection.

[0067] As another implementation method, the ring-type node can be set in the anchor (cable) prestressing application area as needed, and used in conjunction with the rotational coupling energy absorption device to fix the support net at the bottom of the pallet, increase the contact area between the pallet and the support net and the number of mesh wires at the bottom of the pallet, and improve the shear resistance and anti-slip ability of the support net at the pallet.

[0068] Combination Fig. 9The anchor rod or anchor cable passes through the ring node and is fixed by a rotational coupling energy absorbing device 4; the rotational coupling energy absorbing device 4 includes: a main tray 41, a force transmission sleeve 46, a pressure adjustment angle structure and an angle adjustment wedge 42; the main tray 41 directly contacts the support net, and cooperates with the prestressed nut to fix the anchor rod or anchor cable 414 on the surrounding rock with a set prestress, and the support net is fixed by the anchor rod or anchor cable 414.

[0069] An annular groove 45 matching the annular node is provided on one side of the main pallet close to the support net, and the annular node 13 can be embedded in the annular groove 45; a spherical angle adjustment wedge 42 is arranged at the center of the main pallet, and the angle adjustment wedge 42 is embedded in the main pallet and can rotate inside the main pallet, and the anchor rod passes through the main pallet through the hole of the angle adjustment wedge.

[0070] The prestressed force transmission sleeve 46 is placed on the upper outer surface of the main tray (i.e., the side away from the support net), and the anchor rod prestress is transmitted to the main tray 41 through the force transmission sleeve 46; a bearing platform 47 is provided inside the prestressed force transmission sleeve, a flat force transmission disc 412 is provided on the bearing platform 47, and a hollow pressure-releasing angle adjustment structure 413 is provided between the flat force transmission disc 412 and the main tray; the pressure-releasing angle adjustment structure 413 is an internally hollow pancake-shaped ring structure, which is arranged inside the force transmission sleeve, and its lower part is connected to the upper outer surface of the main tray, can be flexibly deformed, and can withstand high-strength pressure.

[0071] The main tray 41, the pressure-adjusting angle structure 413, the flat force transmission plate 412 and the spherical angle-adjusting wedge 42 are all provided with through holes for the anchor rods or anchor cables to pass through.

[0072] As a specific implementation method, Fig.10 The main tray 41 is disc-shaped as a whole, and the main tray is divided into an inner ring and an outer ring; the outer ring is bent outward at a certain angle to form a bent structure 43, which can ensure that the tray further fits the surrounding support net when the surrounding rock deforms and causes the support net to deform and twist. The outermost extension of the disk is an arc structure to prevent the support net from being sheared and damaged by the edge of the tray after being deformed and twisted; the inner ring 44 of the main tray is provided with an annular groove 45, which can embed the annular node area of ​​the support net. At this time, the inner ring 44 of the main tray can directly contact the surface of the surrounding rock, and directly transfer the prestress applied by the anchor rod to the surrounding rock, avoiding the transmission of prestress through the support net. The transmission of prestress is transformed from line contact between the surrounding rock and the support net to surface contact between the surrounding rock and the tray.

[0073] The prestressed force transmission sleeve 46 is supported on the upper surface of the main tray, and a force transmission sleeve bottom platform 49 is provided at the bottom, and the force transmission sleeve bottom platform 49 is in contact with the main tray; a bearing platform 47 is provided inside the force transmission sleeve 46, and the bearing platform 47 can be fixed in an adjustment groove 48 opened on the inner wall of the force transmission sleeve. At this time, a flat force transmission disc 412 is placed on the upper part of the bearing platform, and a prestressed nut 410 is connected to the force transmission disc. The prestress applied by the anchor rod or anchor cable is successively transmitted to the flat force transmission disc 412, the bearing platform 47, the force transmission sleeve 46, and the main tray 41, and finally transmitted to the support net and the surrounding rock surface.

[0074] The pressure-adjusting angle structure is a pancake-shaped ring structure with a hollow interior. The structure is arranged at the lower part of the flat force transfer plate and fixed on the upper surface of the main pallet. When the force on the pallet structure increases and exceeds the bearing limit of the load-bearing platform, the load-bearing platform will fall off, and the upper flat force transfer plate will be pressed onto the pressure-adjusting angle structure. At this time, the structure will adaptively make corresponding deformations according to the force on the flat force transfer plate, so that the force transfer plate will tilt and rotate to match the angle of the middle anchor rod or anchor cable; the diameter of the annular space reserved by the pressure-adjusting angle structure near the middle position of the anchor rod or anchor cable is larger than the diameter of the anchor rod or anchor cable to avoid contact with the anchor rod or anchor cable after twisting.

[0075] An arc-shaped groove 411 is provided in the middle of the flat force transmission disc to accommodate the hemispherical prestressed nut 410 on its upper part; the diameter of the through hole reserved in the middle of the force transmission disc is larger than the diameter of the anchor rod or anchor cable, and is tilted at an angle to fit the position of the anchor rod or anchor cable after twisting, avoiding bending of the anchor rod cable and ensuring its stress transfer effect.

[0076] A spherical groove is provided in the center of the inner circle of the main tray, and the angle adjustment wedge is placed in the spherical groove. The angle adjustment wedge can rotate in the spherical groove to adjust the angle according to the force angle of the anchor rod; the angle adjustment wedge is a 3 / 4 sphere, the middle of the sphere is hollowed out in a cylindrical shape, and the upper half of the sphere is treated as a platform. The angle adjustment wedge can rotate in the spherical groove of the main tray to adjust the angle according to the force angle of the anchor rod or anchor cable; specifically: when the anchor rod rotates due to the complex stress of the surrounding rock, it can drive the angle adjustment wedge to rotate, and then the upper part allows the flat force transmission plate of the angle adjustment structure to tilt, and cooperate with the hemispherical nut to make the anchor rod or anchor cable tilt and rotate. At this time, it is ensured that the anchor rod or anchor cable passes through the tray to avoid bending due to the shear stress of the tray structure due to the tilting rotation, which affects the overall force transmission of the support structure.

[0077] In this embodiment, the anchor rod or anchor cable passes through the central cavity of the rotational coupling energy absorbing device, and prestress is applied to the anchor rod or anchor cable. The prestress of the anchor rod or anchor cable is transferred to the support net and the surrounding rock surface through the rotational coupling energy absorbing device. The annular node of the support net is embedded in the bottom of the main tray of the rotational coupling energy absorbing device. The main tray applies prestress on the surrounding rock surface. The supporting meshes are tightly connected by embedded mesh connecting devices to stably connect adjacent support nets. The supporting components jointly support to form an underground engineering anchor net coupling energy absorption support system. This system can improve the coupling effect of each support component, reduce the weak links of the support system, and maximize the support capacity of each component.

[0078] As an optional implementation, it also includes a monitoring and early warning system, which includes a controller and an early warning unit. The early warning unit includes: a pressure-absorbing energy early warning device and a coupling energy absorption early warning device.

[0079] Specifically, the pressure absorption warning device includes: a first stress monitoring element for monitoring the pressure of the connecting piece on the bottom of the resistance casing, when the first stress monitoring element detects that the pressure of the connecting piece on the bottom of the resistance casing reaches a set first safety load, an alarm is triggered; the design value of the first safety load is specifically: F a =λ*F1, λ is the safety load factor of the support net, which is usually less than 1; F1 is the maximum bearing capacity of the support net.

[0080] In this embodiment, a stress monitoring element is installed at the bottom of the resistance sleeve. When the sliding plug slides to the bottom in the sleeve, the support rod contacts the bottom of the resistance sleeve. At this time, the first stress monitoring element monitors the pressure of the support rod and transmits it to the controller. When the controller determines that the stress of the support net exceeds the first safety load design value F a When the monitoring warning is triggered.

[0081] The coupled energy absorption warning device includes: a second stress monitoring element for monitoring the prestress of the anchor rod or anchor cable, when the stress detected by the second stress monitoring element exceeds the second safety load, an alarm is triggered; the design value of the second safety load is specifically: F b =μ*F2, μ is the safety load factor, usually less than 1; F2 is the maximum bearing capacity of the anchor rod or anchor cable.

[0082] In this embodiment, a stress monitoring element is installed at the bottom of the force transmission sleeve of the rotary coupling energy absorption device to monitor the prestress of the anchor rod or anchor cable; because the force transmission sleeve transmits the prestress of the anchor rod along the flat force transmission plate 412 and the bearing platform 47 all the way to the force transmission sleeve 46, and then the force transmission sleeve 46 presses on the main body tray 41 below, and finally applies the prestress of the anchor rod or anchor cable to the surrounding rock and the support net; therefore, the stress generated between the force transmission sleeve 46 and the main body tray 41 can be used for conversion and monitoring, and finally the prestress of the anchor rod or anchor cable is transmitted to the controller. When the controller determines that the prestress of the anchor rod or anchor cable exceeds the safe load design value F a When the monitoring warning is triggered.

[0083] Under the coupled support action of the support net, butterfly-shaped flexible connection nodes, breakable energy absorption structure, constant resistance energy absorption unit, ring-type nodes, embedded mesh connection device, rotational coupling energy absorption device and constant resistance pressure-yielding energy absorption anchor rod or cable, this embodiment can give full play to the energy efficiency of each support component and realize efficient pressure-yielding support.

[0084] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. An underground engineering anchor-net coupled energy-absorbing support system, characterized in that: include: A plurality of butterfly-shaped flexible connection nodes are arranged on the support net, wherein the butterfly-shaped flexible connection nodes include a breakable energy absorbing structure arranged at a central position, and a plurality of flexible energy absorbing connection structures arranged at the periphery of the breakable energy absorbing structure, and each of the flexible energy absorbing connection structures is sleeved with a constant resistance energy absorbing unit on the outside. When the butterfly-shaped flexible connection node is compressed and deformed, the breakable energy absorbing structure bears the pressure first, and after the breakable energy absorbing structure is broken under pressure, the flexible energy absorbing connection structure is compressed and deformed, and the pressure is absorbed by the constant resistance energy absorbing unit. A plurality of annular nodes arranged on the support net, wherein the annular nodes are arranged at the tray installation location, the anchor rods or anchor cables pass through the annular nodes, and are fixed by a rotating coupling energy absorbing device, wherein the rotating coupling energy absorbing device is used to absorb the prestress of the anchor rods or anchor cables and directly transfer the prestress of the anchor rods or anchor cables to the surrounding rock surface; And / or, the ring-shaped node is arranged at the overlapping position of two support nets, and the two support nets are connected by an embedded mesh connecting device.

2. The underground engineering anchor-net coupled energy absorption support system according to claim 1, characterized in that: The constant resistance energy absorption unit comprises: a resistance sleeve sleeved on the outside of the flexible energy absorption connection structure, the end of the resistance sleeve is open, a sliding plug body is arranged in the opening, a connecting piece is arranged at the bottom of the sliding plug body, and the top of the flexible energy absorption connection structure is connected to the connecting piece; After the breakable energy-absorbing structure breaks under pressure, the flexible energy-absorbing connection structure is stretched toward the outside of the resistance sleeve under pressure, driving the sliding plug to move from the end of the resistance sleeve to the opposite end, thereby achieving constant resistance pressure-releasing energy absorption.

3. An underground engineering anchor-net coupled energy-absorbing support system as claimed in claim 2, characterized in that: The connecting member comprises: two force transmission rods arranged opposite to each other, one end of the two force transmission rods is respectively connected to the bottom of the sliding plug body, and the other end is connected together through a support rod; a connecting rod is also arranged between the two force transmission rods, and the top end of the flexible energy absorption connection structure is connected to the connecting rod; The connecting rod is buckled together by a first connecting unit and a second connecting unit, and the first connecting unit and the second connecting unit are disconnected when the pulling force of the two force transmission rods is lost.

4. The underground engineering anchor-net coupled energy absorption support system according to claim 2, characterized in that: Also includes: The pressure-releasing energy absorption warning device comprises: The first stress monitoring element is used to monitor the pressure of the connector on the bottom of the resistance casing. When the first stress monitoring element detects that the pressure of the connector on the bottom of the resistance casing reaches the set first safety load, an alarm is triggered; the first safety load is specifically: F a =λ*F1, λ is the safety load coefficient of the support net, and F1 is the maximum bearing capacity of the support net.

5. The underground engineering anchor-net coupled energy absorption support system according to claim 1, characterized in that: The breakable energy absorption structure is a cross-shaped connection structure, which connects the four connection ends at the cross-intersection position of the support net; a flexible energy absorption connection structure is connected between two adjacent ends; the flexible energy absorption connection structure is an arc-shaped flexible steel sheet, and the two ends of the steel sheet are respectively connected to the two ends of the cross-shaped connection structure.

6. The underground engineering anchor-net coupled energy absorption support system according to claim 1, characterized in that: The embedded mesh connection device comprises a first plug-in block and a second plug-in block, and the first plug-in block and the second plug-in block can be respectively inserted into the ring node and connected together by threads.

7. The underground engineering anchor-net coupled energy absorption support system according to claim 1, characterized in that: The rotary coupling energy absorption device comprises: a main body tray, a prestressed force transmission sleeve, a pressure-release angle adjustment structure and an angle adjustment wedge; an annular groove adapted to the annular node is provided on the side of the main body tray close to the support net, and the annular node can be embedded in the annular groove; a spherical angle adjustment wedge is provided at the center of the main body tray, and the spherical angle adjustment wedge can rotate in the disc; the prestressed force transmission sleeve is provided on the side of the main body tray away from the support net, a bearing platform is provided in the prestressed force transmission sleeve, a flat force transmission disc is provided on the bearing platform, and a hollow pressure-release angle adjustment structure is provided between the flat force transmission disc and the main body tray; The main body tray, the pressure-adjusting angle structure, the flat force transmission plate and the spherical angle-adjusting wedge are all provided with through holes for the anchor rods or anchor cables to pass through.

8. An underground engineering anchor-net coupled energy-absorbing support system as claimed in claim 7, characterized in that: The upper surface of the flat force transmission disc is provided with an arc groove adapted to the hemispherical prestressed nut; a through hole larger than the diameter of the anchor rod or anchor cable is reserved in the middle of the flat force transmission disc, and the through hole is inclined at a set angle to adapt to the torsion of the anchor rod or anchor cable after being stressed.

9. The underground engineering anchor-net coupled energy absorption support system according to claim 7, characterized in that: The main body tray is disc-shaped, including an inner ring part and an outer ring part. The outer ring part is bent outward at a set angle to form an inverted structure to fit the support net; the outermost extension is an arc structure to avoid shear damage to the support net; the inner ring part is provided with an annular groove, and the annular node area of ​​the support net is embedded in the annular groove; the inner ring part directly contacts the surface of the surrounding rock to directly transfer the prestress applied by the anchor rod or anchor cable to the surrounding rock.

10. The underground engineering anchor-net coupled energy absorption support system according to claim 7, characterized in that: Also includes: A coupling energy absorption warning device, the coupling energy absorption warning device comprising: The second stress monitoring element is used to monitor the prestress of the anchor rod or anchor cable. When the stress detected by the second stress monitoring element exceeds the second safety load, an alarm is triggered; the second safety load is specifically designed as: F b =μ*F2, μ is the safety load factor, and F2 is the maximum bearing capacity of the anchor rod or anchor cable.

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