A multi-point self-expanding energy-releasing yielding bolt

Abstract

The present invention belongs to the technical field of tunnel engineering construction, and discloses a multi-point self-expanding energy-releasing yielding bolt, which comprises a rod body, a yielding tray and a nut sleeved on the rod body. The rod body is connected with at least one yielding unit, and the yielding unit comprises a self-expanding sleeve and a yielding rod which are connected in sequence. The self-expanding sleeve is columnar, and an annular groove is arranged on the outer periphery of the middle part. An expansion anchoring bag is arranged in the groove, and a serpentine bending structure is arranged in the middle of the yielding rod. Each yielding unit in the present invention can independently play the role of anchoring and yielding, achieving the purpose of multi-point yielding and increasing resistance, being used for controlling the sudden violent ejection phenomenon of rock mass at the tunnel face during the construction of high in-situ stress rockburst tunnels, reducing the construction risk at the tunnel face, and ensuring the safety of personnel and equipment during the construction of rockburst tunnels.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel engineering construction, and particularly relates to a multi-point self-expanding energy-releasing yielding bolt. Background Technique

[0002] Rockburst is a dynamic instability phenomenon induced by certain factors after the excavation and unloading of intact hard and brittle surrounding rock under high in-situ stress conditions, often causing catastrophic damage to underground engineering. With the continuous increase in the depth of tunnel construction, the situation of tunnels passing through high-intensity rockburst areas becomes more and more common, and the possibility and harmfulness of rockburst disasters are continuously increasing, seriously threatening the safety of operating personnel and affecting the construction progress.

[0003] Bolts and their combined support methods are commonly used support methods for underground engineering in countries around the world today. However, traditional bolt support technology has poor extensibility and poor energy absorption effect, and it is difficult to effectively resist dynamic impact damage such as rockburst. To effectively control dynamic disasters such as rockburst induced under high in-situ stress conditions, energy-releasing bolts have become an important support form in deep shaft mining mines around the world. Energy-releasing bolts not only have high static pull-out force but also can resist multiple impacts of dynamic loads, and produce a certain overall slip or large deformation during each dynamic impact process, so as to release the kinetic energy accumulated at the impact end and ensure the overall stability of the energy-releasing supported rock mass.

[0004] At present, the energy-releasing bolts used in underground engineering construction at the present stage can be roughly divided into two types: rod extensible type and structural element type. However, in the actual use process, the rod extensible type bolts have disadvantages such as difficult to accurately control deformation parameters and easy breakage of the rod body, and the structural element type yielding bolts have disadvantages such as high cost and easy failure and damage due to delicate structure. Therefore, the energy-releasing bolt support technology for rockburst tunnels urgently needs to be innovated. Summary of the Invention

[0005] To solve the deficiencies in the above-mentioned prior art, the present invention provides a multi-point self-expanding energy-releasing yielding bolt, which is used to control the sudden violent ejection phenomenon of rock mass at the tunnel face during the construction of high in-situ stress rockburst tunnels, reduce the construction risk at the tunnel face, and ensure the safety of personnel and equipment during the construction of rockburst tunnels.

[0006] To achieve the above technical purpose, the technical solution adopted by the present invention is:

[0007] A multi-point self-expanding energy-releasing yielding bolt includes a bolt body, a yielding tray and a nut sleeved on the bolt body. The bolt body is connected with at least one yielding unit. The yielding unit includes a self-expanding sleeve and a yielding rod connected in sequence. The self-expanding sleeve is columnar, and an annular groove is provided on the outer periphery of the middle part. An expansion anchoring bag is arranged in the groove. The middle part of the yielding rod is provided with a serpentine bending structure.

[0008] Further, threads that cooperate with each other are provided at both ends of the self-expanding sleeve and the yielding rod, and the self-expanding sleeve is threadedly connected to the yielding rod.

[0009] Further, the yielding tray is columnar and includes a bearing plate, an impedance ring, and a positioning plate. The impedance ring is in the shape of a hollow ring, and both ends of the impedance ring are respectively connected to the bearing plate and the positioning plate. A threaded hole is provided at the center of the positioning plate, and an arc-shaped boss facing the inside of the impedance plate is provided in the middle of the bearing plate. A through hole for the rod body to pass through is provided at the center of the boss.

[0010] Further, threads are provided at the end of the rod body, and the rod body is threadedly connected to the positioning plate.

[0011] Further, sticking strips are provided at both ends of the expansion and anchorage bag. The length of the expansion and anchorage bag is greater than the circumference of the groove. After the expansion and anchorage bag is wound around the groove for one week, it is fixedly adhered.

[0012] Further, a quick-setting expansion and anchorage bag, a slow-setting expansion and anchorage bag, and a quick-setting expansion and anchorage bag are sequentially placed in the groove from top to bottom.

[0013] Further, the quick-setting expansion and anchorage bag contains a quick-setting anchoring agent and an expansion agent I; the slow-setting expansion and anchorage bag contains a slow-setting anchoring agent and an expansion agent II, and the expansion rate of the expansion agent I is faster than that of the expansion agent II.

[0014] Further, the expansion and anchorage bag has two layers of packaging. The outer layer is a water-proof plastic film, and the inner layer is made of a water-permeable non-woven fabric.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] For the multi-point self-expanding energy-releasing yielding bolt of the present invention, a yielding unit is provided. After the bolt is installed, the expansion and anchorage bag sleeved outside the self-expanding sleeve expands and anchors, squeezing the rock wall, forcing the rock wall to give a great squeezing force to the yielding unit. The serpentine yielding rod can be stretched during large deformations of the tunnel, providing continuous resistance to the surrounding rock, strengthening the tunnel's ability to resist the energy-releasing deformation of the surrounding rock, and at the same time allowing the bolt to move with the deformation of the surrounding rock, reducing the probability of the bolt being pulled off. Even if a part of the bolt breaks under the action of a large tensile force, the remaining part of the bolt can still be anchored by virtue of the squeezing force of the rock wall on the self-expanding sleeve section. Each yielding unit can independently perform the functions of anchoring and yielding, achieving the purpose of multi-point yielding and increasing resistance;

[0017] The multi-point self-expanding energy-releasing yielding bolt of the present invention is such that when the convergence deformation of the tunnel gradually increases, the surrounding rock will gradually squeeze the bearing plate of the yielding tray. Since the position of the positioning plate and the rod body is relatively fixed, the impedance ring in the middle part will generate a large pressure and thus bend. During this process, the impedance ring can provide a relatively continuous and stable resistance to continuously limit the deformation of the surrounding rock while allowing a large deformation amount of the surrounding rock. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0019] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0020] Figure 2 is a schematic structural diagram of the self-expanding sleeve in an embodiment of the present invention;

[0021] Figure 3 is a schematic structural diagram of the yielding tray when it is under pressure in an embodiment of the present invention;

[0022] Figure 4 is a schematic structural diagram of the yielding tray when it is squeezed to the limit value in an embodiment of the present invention.

[0023] Reference numerals: 1 - rod body, 2 - yielding tray, 3 - yielding unit, 4 - nut, 21 - bearing plate, 22 - impedance ring, 23 - positioning plate, 24 - threaded hole, 25 - boss, 31 - self-expanding sleeve, 32 - yielding rod, 33 - quick-setting expansion anchoring bag, 34 - slow-setting expansion anchoring bag. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0025] A multi-point self-expanding energy-releasing yielding bolt, such as Figure 1 shown, includes a rod body 1, a yielding tray 2 and a nut 4 sleeved on the rod body. The rod body 1 is connected to at least one yielding unit 3. The yielding unit 3 includes a self-expanding sleeve 31 and a yielding rod 32 connected in sequence. The self-expanding sleeve 31 is columnar, with an annular groove provided on the outer periphery of the middle part, and an expansion anchoring bag is arranged in the groove. The middle part of the yielding rod 32 is provided with a serpentine bending structure. Preferably, threads that cooperate with each other are provided at both ends of the self-expanding sleeve 31 and the yielding rod 32, and the self-expanding sleeve 31 is threadedly connected to the yielding rod 32.

[0026] Preferably, sticking strips are provided at both ends of the expansion anchoring bag. The length of the medicine bag is greater than the circumference of the groove. After the medicine bag winds around the groove for one week, it is stuck and fixed. In the groove, a quick-setting expansion anchoring bag 33, a slow-setting expansion anchoring bag 34, and a quick-setting expansion anchoring bag 33 are placed in sequence from top to bottom, as Figure 2 shown; the quick-setting expansion anchoring bag 33 contains a quick-setting anchoring agent and an expansion agent I; the slow-setting expansion anchoring bag 34 contains a slow-setting anchoring agent and an expansion agent II. After the expansion agent I / II encounters water, its volume will expand to a certain extent, prompting the volume of the anchoring agent in the medicine bag to expand accordingly. At the same time, the expansion rate of the expansion agent I in the quick-setting expansion anchoring bag is faster than that of the expansion agent II in the slow-setting expansion anchoring bag.

[0027] The expansion anchoring bag has two layers of packaging. The outer layer is a water-proof plastic film for waterproofing and moisture-proofing, and the inner layer is made of water-permeable non-woven fabric. When in use, first tear off the outer water-proof plastic film, and then soak it in water. During this process, Ca(O) in the medicine bag will absorb a certain amount of water, providing conditions for subsequent chemical reactions and volume expansion. The serpentine bending structure of the yielding rod 32 can be stretched during large deformations of the tunnel, providing continuous resistance to the surrounding rock, strengthening the tunnel's ability to resist the energy-releasing deformation of the surrounding rock, and at the same time allowing the bolt to move with the deformation of the surrounding rock, reducing the probability of the bolt being pulled off.

[0028] The yielding tray 2 is columnar, includes a bearing plate 21, an impedance ring 22 and a positioning plate 23. The impedance ring 22 is a hollow ring. Both ends of the impedance ring 22 are respectively connected to the bearing plate 21 and the positioning plate 23. A threaded hole 24 is provided at the center of the positioning plate 23. An arc-shaped boss 25 facing the inside of the impedance plate is provided in the middle of the bearing plate 21. A through hole for the rod body 1 to pass through is provided at the center of the boss 25. Threads are provided at the end of the rod body 1. After the rod body passes through the tray, the end of the rod body is threadedly connected to the positioning plate 23.

[0029] When the convergence deformation of the tunnel gradually increases, the surrounding rock will gradually squeeze the bearing plate 21. Since the position of the positioning plate 23 and the rod body 1 is relatively fixed, the impedance ring 22 in the middle part will generate a large pressure and thus bend, asFigure 3 As shown, during this process, the impedance ring 22 can provide relatively continuous and stable resistance to continuously limit the deformation of the surrounding rock, while allowing a relatively large amount of deformation of the surrounding rock, following the concept of yielding support. When the deformation of the impedance ring 22 reaches its limit value, the boss of the bearing plate 21 comes into contact with the positioning plate 23. At this time, the yielding effect of the impedance ring 22 will fail, and this yielding tray degenerates into an ordinary tray, as Figure 4 shown.

[0030] Before using this bolt, the length of the bolt should be determined according to the geological exploration data and relevant specifications. After determining the length of the bolt, then determine the number of yielding units, as well as the position and number of self-expanding sleeves. Then, fabricate the yielding rod according to the distance between the two self-expanding sleeves. After the yielding rod is fabricated, connect the yielding rods with self-expanding sleeves, and then soak the expansion anchoring bag in water. After the expansion anchoring bag is soaked in water, quickly paste it into the groove of the self-expanding sleeve. The remaining steps such as drilling, cleaning the hole, and anchoring are the same as those in the installation process of conventional bolts.

[0031] After the bolt is installed, the quick-setting expansion anchoring bag on the self-expanding sleeve starts to expand and solidifies within dozens of minutes. Since the drilling diameter is 6 - 8 mm larger than the bolt diameter, during the subsequent expansion process of the quick-setting expansion anchoring bag, the gap between the quick-setting expansion anchoring bag and the hole wall of the drilling can be filled. And because the expansion rate of the expander in the quick-setting expansion anchoring bag is relatively fast, the quick-setting expansion anchoring bags on both sides form a wrapped state around the slow-setting expansion anchoring bag in the middle. The slow-setting expansion anchoring bag in the middle gradually expands slowly in the following dozens of hours and days. Since the upper and lower ends of the slow-setting expansion anchoring bag are restricted by the solidified matter of the already-set quick-setting expansion anchoring bag, the slow-setting expansion anchoring bag will continuously squeeze the rock wall during the subsequent solidification and expansion process, forcing the rock wall to give a great extrusion force to the self-expanding sleeve and the yielding rod. Therefore, after using this bolt, even if a part of the bolt breaks under the action of a relatively large tensile force, the remaining part of the bolt can still play an anchoring role by virtue of the extrusion force of the rock wall on the self-expanding sleeve section. Each yielding unit can independently play the role of anchoring and yielding, achieving the purpose of multi-point yielding and increasing resistance.

[0032] Certainly, the present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A multi-point self-expanding energy-releasing yielding bolt, Characterized in that: It includes a rod body (1), a yielding tray (2) and a nut (4) sleeved on the rod body. The rod body (1) is connected to at least one yielding unit (3). The yielding unit (3) includes a self-expanding sleeve (31) and a yielding rod (32) connected in sequence. The self-expanding sleeve (31) is columnar, with an annular groove provided on the outer periphery of the middle part. An expansion anchoring bag is placed in the groove. The two ends of the expansion anchoring bag are provided with sticking strips. The length of the expansion anchoring bag is greater than the circumference of the groove. After the expansion anchoring bag winds around the groove for one week, it is stuck and fixed. A quick-setting expansion anchoring bag (33), a slow-setting expansion anchoring bag (34), and a quick-setting expansion anchoring bag (33) are placed in the groove from top to bottom in sequence. The middle part of the yielding rod (32) is provided with a serpentine bending structure. Threads that cooperate with each other are provided at both ends of the self-expanding sleeve (31) and the yielding rod (32), and the self-expanding sleeve (31) is threadedly connected to the yielding rod (32); The yielding tray (2) is columnar, including a bearing plate (21), an impedance ring (22) and a positioning plate (23). The impedance ring (22) is a hollow ring. The two ends of the impedance ring (22) are respectively connected to the bearing plate (21) and the positioning plate (23). A threaded hole (24) is provided at the center of the positioning plate (23). An arc-shaped boss (25) facing the inside of the impedance plate is provided in the middle of the bearing plate (21). A through hole for the rod body (1) to pass through is opened at the center of the boss (25).

2. The multi-point self-expanding energy-releasing yielding bolt according to claim 1, Characterized in that: The end of the rod body (1) is provided with threads, and the rod body (1) is threadedly connected to the positioning plate (23).

3. The multi-point self-expanding energy-releasing yielding bolt according to claim 1, Characterized in that: The quick-setting expansion anchoring bag (33) contains a quick-setting anchoring agent and an expansion agent I; the slow-setting expansion anchoring bag (34) contains a slow-setting anchoring agent and an expansion agent II, and the expansion rate of the expansion agent I is faster than that of the expansion agent II.

4. The multi-point self-expanding energy-releasing yielding bolt according to claim 1, Characterized in that: The expansion anchoring bag has two layers of packaging. The outer layer is a water-proof plastic film, and the inner layer is made of water-permeable non-woven fabric.

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