Multi-point combined prestressed fastening roadway supporting anchor rod assembly and construction method

Abstract

The roadway supporting anchor rod assembly comprises an anchor rod main body, an anchor rod expansion cap and an outer tray frame, one end of the anchor rod main body is provided with a wedge-shaped expansion embedding part, the other end of the anchor rod main body is a supporting locking part, an inner sliding hole is formed in the wedge-shaped expansion embedding part, and the supporting locking part is provided with an outer sliding hole; an inner sliding hole of the wedge-shaped expansion embedding part is in sliding fit with the lining expansion column, a sliding block is further installed in the inner sliding hole of the wedge-shaped expansion embedding part in a sliding mode, a linkage rod is fixed to the sliding block, a spring is fixed to the end, away from the sliding block, of the linkage rod, and the spring is located and fixed to the bottom of the inner sliding hole of the wedge-shaped expansion embedding part. The linkage rod is sequentially provided with a plurality of jacking connecting rod assemblies in the length direction, each jacking connecting rod assembly comprises a jacking fixing rod, and the wedge-shaped expansion embedded part is provided with a jacking rod moving hole used for the jacking fixing rod to stretch out. A plurality of prestress fastening point positions are arranged, the structural performance of roadway surrounding rock support is improved, and complex conditions of roadway rock strata can be coped with.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine tunnel support, and in particular to a tunnel support anchor rod assembly with multi-point combined prestressed fastening and a construction method. Background Art

[0002] Anchor rods are commonly used technical equipment in the field of coal mine roadway support. Their working principle is: after anchoring the anchor rod in the deep stable surrounding rock, the anchor rod tray fastened to the tail of the anchor rod is used to suppress the loosening and breaking of the surrounding rock on the surface of the roadway, and at the same time connect the surrounding rock on the surface of the roadway with the deep stable rock to form a stable bearing structure to support the surrounding rock of the roadway. Anchor rod support technology plays an important role in reducing the construction of support structures in the roadway, reducing the cost of roadway support, and improving the efficiency of roadway excavation. Due to the wide applicability of its working principle, anchor rods are also used in areas such as slopes, tunnels, and roads where surrounding rock reinforcement is required. In the early stage of coal mine roadway excavation, the deformation of the surrounding rock of the roadway develops rapidly due to the sudden removal of the bearing body in the roadway space, and the early and timely support of the roadway can effectively reduce the early and late deformation of the surrounding rock of the roadway. Therefore, early rapid and timely support technology has always been the key research direction of roadway support. For conventional anchor support, after the anchor hole is drilled, it is necessary to add anchoring agent into the anchor hole and drive the anchor into it. The anchor can only play a supporting role after the anchoring agent solidifies. During the anchoring and solidification period, the surrounding rock of the tunnel cannot be effectively supported, which will cause the early deformation of the surrounding rock of the tunnel to increase, increase the difficulty of tunnel support, and be unfavorable for the later maintenance of the tunnel.

[0003] Prestressed anchor bolts are made by adding a prestressing device to the top of the anchor bolt. After the anchor bolt body is driven into the tunnel surrounding rock, the mechanical or friction between the device and the anchor bolt hole wall will cause prestress to be generated immediately after the anchor bolt is installed, which will inhibit the deformation and damage of the tunnel surrounding rock, thereby providing early support for the tunnel surrounding rock. After deep mining of coal, the stress level of the tunnel surrounding rock increases, and the early deformation of the tunnel surrounding rock increases significantly. However, the prestressing device of the traditional prestressed anchor bolt has relatively few tight expansion and friction points with the anchor bolt hole. In the deep stress environment, the prestressing point is prone to failure, causing the prestressed anchor bolt to fail. Therefore, it is urgent to develop prestressed anchor bolts with multiple tight expansion and friction points, enhance the resistance of prestressed anchor bolts to deformation and damage of the surrounding rock at the prestressing position, continuously provide prestressing force for the tunnel surrounding rock, thereby effectively reducing the initial deformation of the tunnel surrounding rock, playing a role in strengthening the tunnel support, and providing help for deep coal mining tunnel support. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems pointed out by the background technology, and to provide a tunnel support anchor assembly and construction method with multi-point combined prestressed tightening, a wedge-shaped expansion embedding part and a wedge-shaped expansion matching structure of the anchor expansion cap, a prestressed expansion positioning is formed at the bottom of the anchor hole, and a plurality of tightening connecting rod assemblies are installed and arranged on the linkage rod along the length direction of the anchor body, and multi-point prestressed tightening points are formed by supporting the anchor hole at various positions in the length direction by the tightening rod, so as to realize multi-point prestressed expansion positioning of the anchor and the anchor hole, enhance the resistance of the anchor to the deformation and damage of the surrounding rock strata, and enable the anchor to continue to produce a prestressing force tightening effect after the support is completed, thereby greatly improving the structural performance of the tunnel surrounding rock support.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A tunnel support anchor assembly with multi-point combined prestressed tightening, comprising an anchor body, an anchor expansion cap and an outer tray frame, wherein one end of the anchor body is provided with a wedge-shaped expansion embedding portion, and the other end of the anchor body is a support locking portion, wherein the anchor expansion cap has a wedge-shaped expansion cavity surrounded by a plurality of wedge-shaped expansion arms, and an inner lining expansion column is fixed in the wedge-shaped expansion cavity of the anchor expansion cap from the cavity bottom to the cavity mouth; an inner sliding hole is provided inside the wedge-shaped expansion embedding portion, and the inner sliding hole of the wedge-shaped expansion embedding portion is slidably matched with the inner lining expansion column, and a slider is also slidably installed on the inner sliding hole of the wedge-shaped expansion embedding portion, and a linkage rod is fixed to the slider, and a spring is fixed to the end of the linkage rod away from the slider , the spring is positioned and fixed at the bottom of the inner sliding hole of the wedge-shaped expansion embedding part; the linkage rod is sequentially installed with a plurality of tightening link rod assemblies along the length direction, the tightening link rod assembly includes a tightening rod, and the wedge-shaped expansion embedding part is provided with a tightening rod moving hole for the extension movement of the tightening rod; when the spring is not compressed, the distance between the end of the linkage rod and the bottom of the inner sliding hole reaches a maximum value and the tightening rod does not extend out of the tightening rod moving hole; when the spring is compressed in place, the distance between the end of the linkage rod and the bottom of the inner sliding hole reaches a minimum value and the end of the tightening rod extends out of the tightening rod moving hole and serves as a prestressed tightening point; the outer pallet frame is positioned and installed on the support locking part of the anchor rod body.

[0007] In order to better realize the tunnel support anchor rod assembly of the present invention, the tightening link rod assembly also includes a link rod seat, the link rod seat of the tightening link rod assembly is fixed on the linkage rod, and a plurality of links are hingedly distributed in a circle on the link rod seat of the tightening link rod assembly, and the end of each link rod is hingedly connected to the tightening rod.

[0008] Preferably, the portion of the anchor rod body located in the middle except for the wedge-shaped expansion embedding portion and the support locking portion is the anchor rod body, the inner sliding hole extends from the wedge-shaped expansion embedding portion to a portion of the anchor rod body, and a plurality of tightening connecting rod assemblies are evenly distributed and installed on the linkage rod, wherein a part of the tightening connecting rod assemblies correspond to the tightening rod moving holes of the wedge-shaped expansion embedding portion; the anchor rod body is provided with a tightening rod moving hole, and another part of the tightening connecting rod assemblies correspond to the tightening rod moving holes of the anchor rod body.

[0009] Preferably, a section of the inner sliding hole of the wedge-shaped expansion embedment near the hole mouth is a triangular self-locking section, and the inner wall of the triangular self-locking section of the wedge-shaped expansion embedment is provided with a plurality of annular positive triangles 1 along the length direction, and the outer wall of the lining expansion column is provided with a plurality of inverted triangles along the length direction. When the wedge-shaped expansion embedment moves toward the bottom of the wedge-shaped expansion cavity, the triangular hypotenuse surface A of the positive triangle 1 first contacts in parallel with the triangular hypotenuse surface B of the inverted triangle; with further movement, the triangular hypotenuse surface A of the positive triangle 1 steps over the triangular hypotenuse surface B of the inverted triangle to complete a self-locking operation.

[0010] Preferably, the diameter of the liner expansion column gradually decreases from the bottom of the wedge-shaped expansion cavity to the cavity mouth; the aperture of the triangular self-locking section of the wedge-shaped expansion embedding part remains consistent or gradually decreases from the hole mouth to the end of the triangular self-locking section.

[0011] Preferably, an elastic self-locking piece is fixed at a position of the linkage rod near one end of the spring, and the elastic self-locking piece has a plurality of elastically stretched spring leaves, and each spring leaf end has a ball head that elastically slides in contact with the hole wall of the inner sliding hole, and the hole wall of the inner sliding hole is provided with an annular limiting groove, when the spring is not compressed, the distance between the end of the linkage rod and the bottom of the inner sliding hole is at a maximum value, at which time the spring leaf of the elastic self-locking piece is elastically compressed and the ball head elastically contacts with the hole wall of the inner sliding hole; when the spring is compressed into place, the distance between the end of the linkage rod and the bottom of the inner sliding hole is at a minimum value, at which time the ball head of the elastic self-locking piece falls into the annular limiting groove of the inner sliding hole and is limited and locked.

[0012] Preferably, the outer pallet frame comprises a pallet frame and a pallet plate mounted on the pallet frame, the pallet frame has a rod sleeve in the middle portion thereof which cooperates with the supporting locking portion, and the pallet plate has a rod hole which cooperates with the supporting locking portion.

[0013] Preferably, the support locking portion has an external thread, a locking nut is threadedly connected to the support locking portion, and the end side of the locking nut limits the end side of the rod sleeve that supports the pallet rack.

[0014] A construction method for a tunnel support anchor assembly with multi-point combined prestressed fastening, including a tunnel support anchor assembly, the method comprising:

[0015] S1. Plan several anchor support points in the area to be supported in the coal mine tunnel, drill anchor holes inside the coal mine tunnel at the anchor support points, and drive anchor expansion caps into the bottom of the anchor holes;

[0016] S2, driving the anchor body into the anchor hole, the wedge-shaped expansion embedding part of the anchor body wedge-shapedly enters the wedge-shaped expansion cavity of the anchor expansion cap, and as the wedge-shaped expansion embedding part of the anchor body enters, the wedge-shaped expansion embedding part of the anchor body continuously wedge-shapedly expands the wedge-shaped expansion arms surrounding the wedge-shaped expansion cavity, and the wedge-shaped expansion arms of the anchor expansion cap expand outward and are prestressed and fastened to the anchor hole; at the same time, the inner lining expansion column of the anchor expansion cap pushes the slider and the linkage rod to move toward the spring direction, the spring is compressed, and the ends of the top tightening rods of each top tightening connecting rod assembly are gradually extended from the top tightening rod moving hole and prestressed against the corresponding points of the anchor hole, forming prestressed fastening points distributed along the length direction of the anchor body; until the anchor body is driven into place, the construction of the anchor body is completed;

[0017] S3. An external pallet frame is installed and fixed on the support locking part of each anchor rod body in the area to be supported, and a tunnel support structure is constructed by combining the external pallet frames in the area to be supported.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] (1) The wedge-shaped expansion embedding part of the present invention and the wedge-shaped expansion matching structure of the anchor bolt expansion cap form a prestressed expansion positioning at the bottom of the anchor hole. A plurality of tensioning connecting rod assemblies are installed and arranged on the linkage rod along the length direction of the anchor bolt body. The tensioning connecting rod is used to support various positions in the length direction of the anchor hole to form multiple prestressed fastening points, thereby realizing multiple prestressed expansion positioning between the anchor bolt and the anchor bolt hole, enhancing the anchor bolt's resistance to deformation and damage of the surrounding rock formation, and enabling the anchor bolt to continue to generate a prestressed fastening effect after the support is completed, thereby greatly improving the structural performance of the tunnel surrounding rock support.

[0020] (2) The inner wall of the triangular self-locking section of the wedge-shaped expansion embedded part of the present invention is provided with a plurality of annular positive triangles along the length direction, and the outer wall of the lining expansion column is provided with a plurality of inverted triangles along the length direction, so that after the wedge-shaped expansion embedded part is embedded and installed in place, the wedge-shaped expansion embedded part will not retreat, and can self-lock to maintain the prestressed expansion and tightening state, thereby preventing the rock formation deep in the anchor hole of the tunnel from being damaged and causing the wedge-shaped expansion embedded part to retreat and loosen, effectively improving the performance of the overall anchor support structure, and being able to cope with the complex conditions of the rock formations in the tunnel.

[0021] (3) An elastic self-locking part is fixed at a position of the linkage rod of the present invention near one end of the spring. The elastic self-locking part has a ball head elastically supported by a spring leaf. The hole wall of the inner sliding hole is provided with an annular limiting groove. When the spring is compressed into place, the ball head falls into the annular limiting groove of the inner sliding hole and is limited and locked. The spring is always in a compressed state. The top tightening rods of each top tightening connecting rod assembly always extend out of the top tightening rod moving hole and prestress the anchor hole. The tightening operation of other prestressed tightening points will not be affected by the failure of the anchor rod expansion cap position, and the complex conditions of the tunnel rock formation can be coped with.

[0022] (4) The present invention has multiple prestressed fastening points, and has strong resistance to anchor failure caused by deformation and damage of the surrounding rock at the prestressed position, thereby providing continuous prestressing force fastening for the tunnel support and improving the structural performance of the tunnel surrounding rock support. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a first implementation method of the tunnel support anchor assembly of the present invention;

[0024] Figure 2 It is a structural schematic diagram of the anchor rod body and the anchor rod expansion cap when the wedge-shaped expansion embedding part is just inserted;

[0025] Figure 3 for Figure 2 A partial enlarged schematic diagram of the location of the middle wedge-shaped expansion and embedding part;

[0026] Figure 4 for Figure 2 A partial enlarged schematic diagram of the middle annular limit groove;

[0027] Figure 5 It is a schematic diagram of the structure when the wedge-shaped expansion embedding part is inserted into place;

[0028] Figure 6 for Figure 5 A partial enlarged schematic diagram of the location of the middle wedge-shaped expansion and embedding part;

[0029] Figure 7 It is a three-dimensional structural schematic diagram of assembling the tensioning connecting rod assembly on the linkage rod;

[0030] Figure 8 It is a structural schematic diagram of the second implementation method of the tunnel support anchor assembly of the present invention.

[0031] The names corresponding to the reference numerals in the accompanying drawings are:

[0032] 1-anchor rod body, 11-wedge-shaped expansion embedding part, 111-forward triangle, 12-support locking part, 2-anchor rod expansion cap, 21-wedge-shaped expansion cavity, 22-lining expansion column, 221-inverted triangle, 23-concave and convex friction point, 3-inner sliding hole, 31-tension rod moving hole, 32-annular limit groove, 4-slider, 5-linkage rod, 6-tension connecting rod assembly, 61-connecting rod seat, 62-connecting rod, 63-tensioning fastening rod, 7-spring, 8-outer pallet frame, 81-pallet plate, 9-locking nut, 10-elastic self-locking member, 101-ball head, 102-spring. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with embodiments:

[0034] Example

[0035] like Figure 1 to Figure 7 As shown, a tunnel support anchor assembly with multi-point combined prestressed tightening includes an anchor body 1, an anchor expansion cap 2 and an outer tray frame 8. One end of the anchor body 1 has a wedge-shaped expansion embedding portion 11 (the wedge-shaped expansion embedding portion 11 is wedge-embedded with the anchor expansion cap 2 and expands the anchor expansion cap 2, so that the anchor expansion cap 2 is prestressed and fixed in the anchor hole), and the other end of the anchor body 1 is a support locking portion 12 (the support locking portion 12 is used for tunnel support installation). The anchor expansion cap 2 has a wedge-shaped expansion cavity 21 surrounded by a plurality of wedge-shaped expansion arms (when the wedge-shaped expansion embedding portion 11 is embedded in the wedge-shaped expansion cavity 21, each wedge-shaped expansion arm of the anchor expansion cap 2 is expanded and prestressed and firmly fixed in the anchor hole), and an inner lining expansion column 22 is fixed in the wedge-shaped expansion cavity 21 of the anchor expansion cap 2 from the bottom of the cavity to the cavity mouth (such as Figure 2 As shown, the liner expansion column 22 is placed in the wedge-shaped expansion cavity 21, the bottom of the liner expansion column 22 is fixed to the bottom of the wedge-shaped expansion cavity 21, the top of the liner expansion column 22 is flush with the mouth of the wedge-shaped expansion cavity 21, and the wedge-shaped expansion cavity 21, excluding the liner expansion column 22, forms a wedge-shaped embedding cavity corresponding to the wedge-shaped expansion embedding portion 11). The wedge-shaped expansion embedding portion 11 has an inner sliding hole 3 inside, and the inner sliding hole 3 of the wedge-shaped expansion embedding portion 11 is slidably matched with the liner expansion column 22 (when assembling, the liner expansion column 22 extends into the inner sliding hole 3 accordingly), and the inner sliding hole 3 of the wedge-shaped expansion embedding portion 11 is also slidably installed with a slider 4 (when the liner expansion column 22 extends into the inner sliding hole 3 and can hold the slider 4, with the embedding movement of the wedge-shaped expansion embedding portion 11, the liner expansion column 22 pushes the slider 4 to slide in the inner sliding hole 3).

[0036] like Figure 2As shown, the slider 4 is fixed with a linkage rod 5, and a spring 7 is fixed to one end of the linkage rod 5 away from the slider 4 (that is, the end away from the anchor rod expansion cap 2), and the spring 7 is positioned and fixed at the bottom of the inner sliding hole 3 of the wedge-shaped expansion embedding part 11. The linkage rod 5 is sequentially installed with a plurality of top tightening link assemblies 6 along the length direction, and the top tightening link assemblies 6 include a top tightening rod 63, and the wedge-shaped expansion embedding part 11 is provided with a top tightening rod moving hole 31 for the top tightening rod 63 to extend and move (the aperture of the top tightening rod moving hole 31 is larger than that of the wedge-shaped expansion embedding part 11, and the wedge-shaped expansion embedding part 11 can adaptively telescopically move in the top tightening rod moving hole 31, and the top tightening rod moving hole 31 can cope with the telescopic movement of the wedge-shaped expansion embedding part 11 with a certain inclination). When the spring 7 is not compressed, the distance between the end of the linkage rod 5 and the bottom of the inner sliding hole 3 reaches a maximum value and the top tightening rod 63 does not extend out of the top tightening rod moving hole 31. At this time, the top tightening rod 63 is almost flush with the outer wall of the anchor rod body 1, and the slider 4 is not supported and slid by the lining expansion column 22. When the spring 7 is compressed into place (the present invention has an extreme positioning position for compression into place, and an elastic self-locking piece 10 is used to cooperate with the annular limit groove 32 for positioning), the distance between the end of the linkage rod 5 and the bottom of the inner sliding hole 3 reaches a minimum value and the end of the top tightening rod 63 extends out from the top tightening rod moving hole 31 and serves as a prestressed tightening point; at this time, the top tightening rod 63 extends out from the top tightening rod moving hole 31 and exceeds a part of the outer wall of the anchor rod body 1 and is tightly held and positioned against the anchor hole wall. A point where the end of the top tightening rod 63 is prestressed against the anchor hole wall is a prestressed tightening point. If there are multiple top tightening connecting rod assemblies 6 on the linkage rod 5, multiple prestressed tightening points are formed. In this way, even if collapse or geological loosening occurs at the position of the anchor rod expansion cap 2, each prestressed tightening point will allow the tunnel support anchor rod assembly to be tightly fixed in the tunnel rock, greatly enhancing the anchor support capacity of the tunnel support anchor rod assembly. The outer pallet frame 8 is positioned and installed on the support locking portion 12 of the anchor rod body 1, and the outer pallet frame 8 can be used for the construction and installation of the support structure layer.

[0037] In some embodiments, Figure 7 As shown, the top connecting rod assembly 6 also includes a connecting rod seat 61, the connecting rod seat 61 of the top connecting rod assembly 6 is fixed on the linkage rod 5, and a plurality of connecting rods 62 are hingedly connected to the connecting rod seat 61 of the top connecting rod assembly 6 in a circumferential distribution, see Figure 7 A connecting rod seat 61 is hinged with four connecting rods 62, and a top tightening rod 63 is hinged at the end of each connecting rod 62. The ends of the four connecting rods 62 are all hinged with a top tightening rod 63. The four top tightening rods 63 are tightly fixed to the anchor holes in a circularly symmetrical four-point prestressed positioning manner.

[0038] In some embodiments, Figure 8As shown, the anchor rod body 1 has a wedge-shaped expansion embedding portion 11 and a support locking portion 12, and the portion located in the middle is the anchor rod body. The inner sliding hole 3 extends from the wedge-shaped expansion embedding portion 11 to a portion of the anchor rod body ( Figure 1 In the first embodiment, the inner sliding hole 3 is slightly longer than the wedge-shaped expansion embedding portion 11, and the tensioning connecting rod assembly 6 is mainly concentrated at the corresponding position of the wedge-shaped expansion embedding portion 11; Figure 8 In the second embodiment, the inner sliding hole 3 is longer than the wedge-shaped expansion embedding portion 11, and can cover more parts of the anchor rod body according to the specific conditions of the tunnel rock formation, so that more top-tightening link rod assemblies 6 will be arranged on the linkage rod 5, and more top-tightening link rod assemblies 6 will form more prestressed fastening points, making it easier for the tunnel support anchor rod assembly to be fixed in the rock formation, and even if geological damage occurs at certain positions along the length direction of the anchor hole, it still has a strong anchor support effect). A plurality of top-tightening link rod assemblies 6 are evenly distributed and installed on the linkage rod 5, and a part of the top-tightening link rod assemblies 6 correspond to the top-tightening rod moving holes 31 of the wedge-shaped expansion embedding portion 11. The anchor rod body is provided with a top-tightening rod moving hole 31, and another part of the top-tightening link rod assemblies 6 correspond to the top-tightening rod moving hole 31 of the anchor rod body.

[0039] In some embodiments, Figure 2 , Figure 3 As shown, a section of the inner sliding hole 3 of the wedge-shaped expansion embedding portion 11 near the hole opening is a triangular self-locking section, and the inner wall of the triangular self-locking section of the wedge-shaped expansion embedding portion 11 is provided with a plurality of annular positive triangular bodies 111 along the length direction, and the outer wall of the liner expansion column 22 is provided with a plurality of inverted triangular bodies 221 along the length direction. When the wedge-shaped expansion embedding portion 11 moves toward the bottom of the wedge-shaped expansion cavity 21, the triangular hypotenuse surface A of the positive triangular body 111 first contacts with the triangular hypotenuse surface B of the inverted triangular body 221 in parallel (as shown in FIG. Figure 3 As shown in the figure, the forward triangle 111 and the inverted triangle 221 are in a positive and negative wedge-shaped structure, so that the forward triangle 111 can easily step over the inverted triangle 221). With further movement, the triangular hypotenuse surface A of the forward triangle 111 steps over the triangular hypotenuse surface B of the inverted triangle 221 to complete a one-step self-locking operation. The forward triangle 111 and the inverted triangle 221 are both in annular structures. The forward triangle 111 steps over the inverted triangle 221 step by step and is embedded with the wedge-shaped expansion embedding part 11. However, the wedge-shaped expansion embedding part 11 cannot be withdrawn from the wedge-shaped expansion cavity 21, because once the forward triangle 111 steps over the inverted triangle 221, as shown in the figure, the forward triangle 111 steps over the inverted triangle 221 step by step. Figure 6As shown, under the action of prestress, the wedge-shaped large head end of the forward triangle 111 and the wedge-shaped large head end of the reverse triangle 221 are just supported to prevent the wedge-shaped expansion embedded part 11 from retreating. The present invention adopts the above self-locking structure, so that after the wedge-shaped expansion embedded part 11 is embedded and installed in place, the wedge-shaped expansion embedded part 11 will not retreat, and the prestressed expansion and tightening state can be maintained in a self-locking manner, preventing the rock formation deep in the tunnel anchor hole from being damaged and causing the wedge-shaped expansion embedded part 11 to retreat and loosen.

[0040] like Figure 3 As shown, in some preferred embodiments, the diameter of the liner expansion column 22 gradually decreases from the bottom of the wedge-shaped expansion cavity 21 to the cavity mouth, as shown in FIG. Figure 6 As shown, the cross-sectional size of the liner expansion column 22 decreases from the bottom of the wedge-shaped expansion cavity 21 to the cavity opening, forming a large end near the bottom of the wedge-shaped expansion cavity 21 and a small end near the cavity opening of the wedge-shaped expansion cavity 21. The aperture of the triangular self-locking section of the wedge-shaped expansion embedded part 11 is consistent or gradually reduced from the hole opening to the end of the triangular self-locking section.

[0041] In some embodiments, Figure 4 As shown, an elastic self-locking member 10 is fixed at one end of the linkage rod 5 near the spring 7. The elastic self-locking member 10 has a plurality of elastically stretched spring leaves 102 (such as Figure 4 As shown, the spring leaf 102 is elastically stretched obliquely), and each spring leaf 102 has a ball head 101 at the end thereof in elastic sliding contact with the hole wall of the inner sliding hole 3. The hole wall of the inner sliding hole 3 is provided with an annular limiting groove 32. When the spring 7 is not compressed, the distance between the end of the linkage rod 5 and the bottom of the inner sliding hole 3 is at a maximum value. At this time, the spring leaf 102 of the elastic self-locking member 10 is elastically compressed and the ball head 101 is in elastic contact with the hole wall of the inner sliding hole 3 (as the slider 4 pushes the linkage rod 5 to move, the ball head 101 elastically slides on the hole wall of the inner sliding hole 3). When the spring 7 is compressed in place, the distance between the end of the linkage rod 5 and the bottom of the inner slide hole 3 is at a minimum value. At this time, the ball head 101 of the elastic self-locking member 10 falls into the annular limit groove 32 of the inner slide hole 3 and is locked in position. The spring leaf 102 of the elastic self-locking member 10 is elastically compressed, so the ball head 101 slides to the position of the annular limit groove 32 and can easily fall into the annular limit groove 32 of the inner slide hole 3. Once the ball head 101 falls in, it will not slide left and right from the annular limit groove 32 under the elastic force of the spring leaf 102 and is locked in position. When the ball head 101 falls into the annular limit groove 32 of the inner slide hole 3 and is locked in position, the spring 7 is always in a compressed state, and the top tightening rods 63 of each top tightening connecting rod assembly 6 always extend out of the top tightening rod moving hole 31 and prestress the anchor hole, and the fastening operation of other prestressed fastening points will not be affected by the failure of the anchor rod expansion cap 2 position. The outer side wall of the anchor rod expansion cap 2 of the present invention can be provided with concave and convex friction points 23 to enhance the friction performance with the anchor hole and strengthen the fastening performance.

[0042] like Figure 1 , Figure 8 As shown, the outer pallet frame 8 includes a pallet frame and a pallet plate 81 mounted on the pallet frame, the pallet frame has a rod sleeve in the middle thereof that matches the support locking portion 12, and the pallet plate 81 has a rod hole that matches the support locking portion 12. The support locking portion 12 has an external thread, and a locking nut 9 is threadedly connected to the support locking portion 12, and the end side of the locking nut 9 limits the end side of the rod sleeve that supports the pallet frame.

[0043] A construction method for a tunnel support anchor assembly with multi-point combined prestressed fastening, comprising the tunnel support anchor assembly of the present invention, the method comprising:

[0044] S1. Plan several anchor support points in the area to be supported in the coal mine tunnel, drill anchor holes inside the coal mine tunnel at the anchor support points, and drive the anchor expansion cap 2 into the bottom of the anchor hole.

[0045] S2, drive the anchor body 1 into the anchor hole, and the wedge-shaped expansion embedding part 11 of the anchor body 1 wedges into the wedge-shaped expansion cavity 21 of the anchor expansion cap 2. As the wedge-shaped expansion embedding part 11 of the anchor body 1 wedges into the anchor body, the wedge-shaped expansion embedding part 11 of the anchor body 1 continuously wedges and expands to form the wedge-shaped expansion arms of the wedge-shaped expansion cavity 21, and the wedge-shaped expansion arms of the anchor expansion cap 2 expand outward and are prestressed and fastened to the anchor hole. At the same time, the inner lining expansion column 22 of the anchor expansion cap 2 pushes the slider 4 and the linkage rod 5 to move toward the spring 7, and the spring 7 is compressed. The ends of the top tightening rods 63 of each top tightening connecting rod assembly 6 gradually extend from the top tightening rod moving hole 31 and are prestressed with the corresponding points of the anchor hole, forming prestressed fastening points distributed along the length direction of the anchor body 1. Until the anchor body 1 is driven into place, the construction of the anchor body 1 is completed.

[0046] S3. An external pallet frame 8 is installed and fixed on the support locking portion 12 of each anchor body 1 in the area to be supported, and a tunnel support structure is constructed by combining the external pallet frames 8 in the area to be supported.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A tunnel support anchor assembly with multi-point combined prestressed fastening, characterized in that: The invention comprises an anchor rod body (1), an anchor rod expansion cap (2) and an outer tray frame (8), wherein one end of the anchor rod body (1) is provided with a wedge-shaped expansion embedding portion (11), and the other end of the anchor rod body (1) is a support locking portion (12), and the anchor rod expansion cap (2) is provided with a wedge-shaped expansion cavity (21) surrounded by a plurality of wedge-shaped expansion arms, and an inner lining expansion column is fixed in the wedge-shaped expansion cavity (21) of the anchor rod expansion cap (2) from the cavity bottom to the cavity mouth. (22); the wedge-shaped expansion embedded part (11) has an inner sliding hole (3) inside, the inner sliding hole (3) of the wedge-shaped expansion embedded part (11) is slidably matched with the lining expansion column (22), the inner sliding hole (3) of the wedge-shaped expansion embedded part (11) is also slidably mounted with a slider (4), the slider (4) is fixed with a linkage rod (5), the end of the linkage rod (5) away from the slider (4) is fixed with a spring (7), the spring (7) is positioned The invention relates to a method for fixing a plurality of jacking connecting rod assemblies (6) on a bottom of an inner sliding hole (3) fixed to a wedge-shaped expansion embedding portion (11); the linkage rod (5) is sequentially installed with a plurality of jacking connecting rod assemblies (6) along the length direction, the jacking connecting rod assemblies (6) comprising a jacking tightening rod (63); the wedge-shaped expansion embedding portion (11) is provided with a jacking rod moving hole (31) for the jacking tightening rod (63) to extend and move; when the spring (7) is not compressed, the distance between the end of the linkage rod (5) and the bottom of the inner sliding hole (3) reaches a maximum value and the jacking tightening rod (63) does not extend out of the jacking rod moving hole (31); when the spring (7) is compressed into place, the distance between the end of the linkage rod (5) and the bottom of the inner sliding hole (3) reaches a minimum value and the end of the jacking tightening rod (63) extends out of the jacking rod moving hole (31) and serves as a prestressed tightening point; the outer tray frame (8) is positioned and installed on the supporting locking portion (12) of the anchor rod body (1).

2. A tunnel support anchor assembly with multi-point combined prestressed fastening according to claim 1, characterized in that: The tensioning connecting rod assembly (6) further comprises a connecting rod seat (61), wherein the connecting rod seat (61) of the tensioning connecting rod assembly (6) is fixed on the linkage rod (5), and a plurality of connecting rods (62) are hingedly connected in a circumferential manner on the connecting rod seat (61) of the tensioning connecting rod assembly (6), and the end of each connecting rod (62) is hingedly connected to the tensioning fastening rod (63).

3. A tunnel support anchor assembly with multi-point combined prestressed fastening according to claim 1 or 2, characterized in that: The anchor rod body (1) has a central portion other than the wedge-shaped expansion embedding portion (11) and the support locking portion (12), the inner sliding hole (3) extending from the wedge-shaped expansion embedding portion (11) to a portion of the anchor rod body, a plurality of tensioning connecting rod assemblies (6) are evenly distributed and installed on the linkage rod (5), a portion of the tensioning connecting rod assemblies (6) corresponding to the tensioning rod moving holes (31) of the wedge-shaped expansion embedding portion (11); the anchor rod body is provided with a tensioning rod moving hole (31), and another portion of the tensioning connecting rod assemblies (6) corresponds to the tensioning rod moving holes (31) of the anchor rod body.

4. The multi-point combined prestressed fastening tunnel support anchor assembly according to claim 1 is characterized in that: A section of the inner sliding hole (3) of the wedge-shaped expansion embedding part (11) near the hole opening is a triangular self-locking section. The inner wall of the triangular self-locking section of the wedge-shaped expansion embedding part (11) is provided with a plurality of annular positive triangular bodies (111) along the length direction. The outer wall of the lining expansion column (22) is provided with a plurality of negative triangular bodies (221) along the length direction. When the wedge-shaped expansion embedding part (11) moves toward the bottom of the wedge-shaped expansion cavity (21), the triangular hypotenuse surface A of the positive triangular body (111) first contacts in parallel with the triangular hypotenuse surface B of the negative triangular body (221); with further movement, the triangular hypotenuse surface A of the positive triangular body (111) steps over the triangular hypotenuse surface B of the negative triangular body (221) to complete a one-step self-locking operation.

5. The multi-point combined prestressed fastening tunnel support anchor assembly according to claim 4 is characterized in that: The diameter of the liner expansion column (22) gradually decreases from the bottom of the wedge-shaped expansion cavity (21) to the cavity mouth; the aperture of the triangular self-locking section of the wedge-shaped expansion embedded part (11) remains consistent or gradually decreases from the hole mouth to the end of the triangular self-locking section.

6. The multi-point combined prestressed fastening tunnel support anchor assembly according to claim 1 is characterized in that: An elastic self-locking member (10) is fixed to a position of the linkage rod (5) near one end of the spring (7), and the elastic self-locking member (10) has a plurality of elastically spread spring leaves (102), and the end of each spring leaf (102) has a ball head (101) that elastically slides in contact with the hole wall of the inner sliding hole (3), and the hole wall of the inner sliding hole (3) is provided with an annular limiting groove (32). When the spring (7) is not compressed, the distance between the end of the linkage rod (5) and the bottom of the inner sliding hole (3) is at a maximum value, at which time the spring leaf (102) of the elastic self-locking member (10) is elastically compressed and the ball head (101) is in elastic contact with the hole wall of the inner sliding hole (3); when the spring (7) is compressed into place, the distance between the end of the linkage rod (5) and the bottom of the inner sliding hole (3) is at a minimum value, and at which time the ball head (101) of the elastic self-locking member (10) falls into the annular limiting groove (32) of the inner sliding hole (3) and is locked in position.

7. The multi-point combined prestressed fastening tunnel support anchor assembly according to claim 1 is characterized in that: The outer pallet frame (8) comprises a pallet frame and a pallet plate (81) mounted on the pallet frame, wherein the middle portion of the pallet frame has a rod sleeve matched with the support locking portion (12), and the pallet plate (81) has a rod hole matched with the support locking portion (12).

8. The multi-point combined prestressed fastening tunnel support anchor assembly according to claim 7 is characterized in that: The support locking portion (12) has an external thread, and a locking nut (9) is threadedly connected to the support locking portion (12), and the end side of the locking nut (9) limits the end side of the rod sleeve that supports the pallet frame.

9. A construction method for a tunnel support anchor assembly with multi-point combined prestressed fastening, characterized in that: The tunnel support anchor assembly comprising any one of claims 1 to 8, wherein the method comprises: S1. Planning a number of anchor support points in the area to be supported in the coal mine tunnel, drilling anchor holes inside the coal mine tunnel at the anchor support points, and driving anchor expansion caps (2) into the bottom of the anchor holes; S2. The anchor rod body (1) is driven into the anchor rod hole. The wedge-shaped expansion embedding portion (11) of the anchor rod body (1) is wedge-shaped into the wedge-shaped expansion cavity (21) of the anchor rod expansion cap (2). As the wedge-shaped expansion embedding portion (11) of the anchor rod body (1) is wedge-shapedly entered, the wedge-shaped expansion embedding portion (11) of the anchor rod body (1) continuously expands in a wedge-shaped manner to form various wedge-shaped expansion arms of the wedge-shaped expansion cavity (21). The various wedge-shaped expansion arms of the anchor rod expansion cap (2) expand outwards and are prestressed and tightened with the anchor rod hole. At the same time, the inner lining expansion column (22) of the anchor bolt expansion cap (2) pushes the slider (4) and the linkage rod (5) to move in the direction of the spring (7), the spring (7) is compressed, and the ends of the top tightening rods (63) of each top tightening connecting rod assembly (6) are gradually extended from the top tightening rod moving hole (31) and prestressed against the corresponding points of the anchor bolt hole, forming prestressed tightening points distributed along the length direction of the anchor bolt body (1); until the anchor bolt body (1) is driven into place, the construction of the anchor bolt body (1) is completed; S3. An external pallet frame (8) is installed and fixed on the support locking part (12) of each anchor rod body (1) in the area to be supported, and a tunnel support structure is constructed by combining the external pallet frames (8) in the area to be supported.

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