A pressure relief anchor pipe

Abstract

The present invention provides a pressure relief anchor pipe, which relates to the technical field of anchor pipes, and includes a pipe body, an end elastic member and a resistance increasing member. One end of the pipe body is used to extend into a hole, and the other end is located outside the hole. The hole is formed in the surrounding rock. The end elastic member is arranged on the pipe body outside the hole, and one end of the end elastic member is used to transmit elastic force to the surrounding rock, and the other end can transmit elastic force to the pipe body. The resistance increasing member is arranged between the pipe body in the hole and the inner wall of the hole. The resistance increasing member contacts the outer wall of the pipe body and the inner wall of the hole. When subjected to stress applied by deformation of the surrounding rock, the resistance increasing member can move relative to the pipe body and generate friction. The solution provided by the present invention can improve the pressure relief energy absorption capacity, enhance the stability of the surrounding rock, and has a simple structure.

Description

Technical Field

[0001] The invention relates to the technical field of anchor pipes, in particular to a pressure relief anchor pipe. Background Art

[0002] Anchor pipe support is widely used in tunnel construction, foundation pit construction and slope stability reinforcement. Anchor pipe is a pipe body made of steel pipe. During construction, the anchor pipe is inserted into the pre-drilled hole. The anchor section formed by anchor pipe grouting combines the unstable rock mass or surrounding rock with the stable rock mass, thereby achieving the purpose of support. Anchor pipe can actively reinforce the rock and soil mass, enable the rock and soil mass to give full play to its own stability, effectively control the deformation of the rock and soil mass, maximize the protection of the surrounding rock integrity, and prevent the overall collapse and damage of the rock and soil mass.

[0003] Compared with anchor rods, anchor pipes have strong bearing capacity, high anchoring force and good shear and bending resistance. For underground engineering structures under weak and broken geological conditions, anchor support needs to be anchored to a certain depth in stable strata to play a role, and the support effect is often poor in broken surrounding rocks; after the anchoring section of the anchor pipe is grouted, the inside and outside of the anchor pipe are wrapped by slurry, and the anchoring effect is better than that of the anchor rod, and it does not need to be anchored to a certain depth in stable strata. It can rely on the anchoring section formed by its own grouting to play a supporting role, which is suitable for supporting key parts of dangerous underground space projects under complex geological conditions. Therefore, in areas with poor geological conditions in underground space projects such as foundation pit projects and tunnel projects, anchor pipes are often installed to resist deformation and achieve the purpose of support. However, ordinary anchor pipes are generally pressure-grouted through the pipe body to form a full-length adhesive anchor pipe, which does not have pressure relief capacity and has a limited ultimate tensile length; ordinary pressure relief anchor pipes have a more complex structure and insufficient pressure relief stroke. When the surrounding rock undergoes a large deformation, ordinary anchor pipes cannot meet the requirements of engineering safety to adapt to the large deformation of the surrounding rock, resulting in the anchor pipe anchor head failure, being pulled off and other adverse conditions, thereby causing the anchor pipe to lose its support function and even leading to engineering accidents. Summary of the invention

[0004] The purpose of the present invention is to provide a pressure relief anchor pipe to solve the problems existing in the above-mentioned prior art, improve the pressure relief energy absorption capacity, enhance the stability of the surrounding rock and have a simple structure.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a pressure relief anchor pipe, comprising a pipe body, an end elastic member and a resistance increasing member, wherein one end of the pipe body is used to extend into a hole, and the other end is located outside the hole, the hole is formed in the surrounding rock, the end elastic member is arranged on the pipe body outside the hole, and one end of the end elastic member is used to transmit the elastic force to the surrounding rock, and the other end can transmit the elastic force to the pipe body, the resistance increasing member is arranged between the pipe body in the hole and the inner wall of the hole, the resistance increasing member is in contact with the outer wall of the pipe body and the inner wall of the hole, and the resistance increasing member can move relative to the pipe body and generate friction when subjected to stress exerted by deformation of the surrounding rock.

[0007] Preferably, the end elastic member includes two annular pads, an elastomer and a nut, the two annular pads are both sleeved on the tube body outside the hole, there is a gap between the two annular pads, the elastomer is clamped between the two annular pads, one annular pad is arranged close to the hole mouth and rests against the surrounding rock at the hole mouth, and the other annular pad is threadedly connected to the tube body on the side away from the elastomer, and rotating the nut can put the elastomer in a compressed state.

[0008] Preferably, a plurality of the elastic bodies are provided, the elastic bodies are springs, and the plurality of the elastic bodies are evenly arranged between the two annular gaskets around the circumference of the tube body.

[0009] Preferably, it also includes a casing, which is sleeved on one end of the tube body extending into the hole, and a conical head is fixedly provided on one end of the casing facing the bottom of the hole, the large end of the conical head is fixedly connected to the casing, and the small end faces the bottom of the hole, and a plurality of grouting holes are opened on the conical head, and a small grouting plug is provided in the annular gap between the casing and the tube body, and a large grouting plug is outerly provided on the casing, the large grouting plug is located on the side of the resistance increasing part facing the bottom of the hole, and the small grouting plug is located on the side of the large grouting plug facing the bottom of the hole, the resistance increasing part is fixedly provided on the casing, and the casing can move relative to the tube body under the action of external force.

[0010] Preferably, the resistance increasing member comprises a plurality of resistance increasing units, the plurality of resistance increasing units are evenly arranged along the length direction and the circumferential direction of the tube body, and the resistance increasing units are all fixedly arranged on the sleeve.

[0011] Preferably, the drag increasing unit is a groove structure with two wings made of steel, the drag increasing unit is in a "U" shape or a "V" shape, the drag increasing unit passes through the sleeve and is fixed on the sleeve, and the two side wing tips of the drag increasing unit are in contact with the tube body and the inner wall of the hole respectively.

[0012] Preferably, a check valve is provided at the end opening of the tube body.

[0013] Preferably, the outer wall of the tube body on the side of the small slurry stopper facing the bottom of the hole and the outside of the check valve are covered with an isolation layer, and the adhesion between the isolation layer and the slurry is smaller than the adhesion between the outer wall of the tube body and the check valve and the slurry.

[0014] Preferably, a sealing structure is provided between one end of the sleeve facing the orifice and the tube body.

[0015] Preferably, the resistance increasing unit has elastic deformation capability, and when the resistance increasing unit is assembled, the resistance increasing unit applies a prestress to the tube body.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] (1) The pressure relief anchor pipe provided by the present invention has a two-stage pressure relief process. The first stage is the pressure relief of the end elastic member, and the second stage is the pressure relief of the resistance increasing member. The pressure relief energy absorption capacity is strong.

[0018] (2) The pressure relief anchor pipe provided by the present invention is highly practical and has a simple structure. It can be installed in key locations of dangerous and large underground space projects under complex geological conditions to effectively ensure their stability.

[0019] (3) The pressure relief anchor pipe provided by the present invention has a strong bearing capacity, high anchoring force and good shear and bending resistance, which can effectively reduce the occurrence of anchor failure of the anchor pipe, and strengthen the surrounding rock by grouting, thereby improving the overall stability of the surrounding rock. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the overall structure of the pressure relief anchor pipe provided by the present invention;

[0022] Figure 2 yes Figure 1 Middle AA section view;

[0023] Figure 3 yes Figure 1 Middle BB section view;

[0024] Figure 4 yes Figure 1 Middle CC section view;

[0025] Figure 5 yes Figure 1Schematic diagram of the connection structure of the check valve;

[0026] Figure 6 It is the force analysis diagram of a single resistance-increasing unit;

[0027] Figure 7 It is the force analysis diagram between the entire resistance increasing component and the tube body;

[0028] Figure 8 yes Figure 1 Schematic diagram of the pressure relief principle of the medium pressure relief anchor pipe.

[0029] In the figure: 1, surrounding rock; 2, pipe body; 3, nut; 4, elastomer; 5, annular gasket; 6, casing; 7, resistance increasing unit; 8, large slurry stop plug; 9, small slurry stop plug; 10, isolation layer; 11, check valve; 11a, valve body; 11b, valve disc; 11c, rocker; 12, grouting hole; 13, external thread; 14, conical head; 15, annular sealing plate. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The purpose of the present invention is to provide a pressure relief anchor pipe to solve the problems existing in the above-mentioned prior art, improve the pressure relief energy absorption capacity, have a simple structure, and enhance the stability of the surrounding rock.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] The present invention provides a pressure relief anchor pipe, which is suitable for controlling key parts of dangerous and large underground space projects, such as Figure 1~Figure 5 As shown, it includes a tube body 2, an end elastic member and a resistance-increasing member. One end of the tube body 2 is used to extend into the hole, and the other end is located outside the hole. The hole is formed in the surrounding rock 1, and the hole is a drilled hole. During grouting, the slurry flows into the drilled hole through the hollow cavity in the tube body 2 and the grouting hole 12. The end elastic member is arranged on the tube body 2 outside the hole, and one end of the end elastic member is used to transfer the elastic force to the surrounding rock 1, and the other end can transfer the elastic force to the tube body 2. The resistance-increasing member is arranged between the tube body 2 in the hole and the inner wall of the hole. The resistance-increasing member contacts the outer wall of the tube body 2 and the inner wall of the hole. When subjected to the stress exerted by the deformation of the surrounding rock 1, the resistance-increasing member can move relative to the tube body 2 and generate friction.

[0034] The pressure relief anchor pipe provided by the present invention can realize a two-stage pressure release (also called pressure relief) process. The pressure release in the first stage is realized by compression or tensile deformation of the elastic member at the end. The pressure release in this stage can release the stress of the surrounding rock to a certain extent. The pressure release in the second stage is that the resistance increasing member is relatively displaced relative to the pipe body 2, and friction is generated between the two, so as to realize the pressure release process in the form of friction force. The pressure release in this stage can greatly release the stress of the surrounding rock with large deformation, and thus the pressure relief anchor pipe provided by the present invention improves the pressure relief capacity.

[0035] In another specific embodiment, the end elastic member includes two annular pads 5, an elastomer 4 and a nut 3. The two annular pads 5 are both sleeved on the tube body 2 outside the hole. There is a gap between the two annular pads 5. The elastomer 4 is clamped between the two annular pads 5. One annular pad 5 is arranged close to the hole mouth and rests on the surrounding rock 1 at the hole mouth. The other annular pad 5 is threadedly connected with a nut 3 on the side of the tube body 2 away from the elastomer 4. Rotating the nut 3 can put the elastomer 4 in a compressed state. The two annular pads 5 can both move along the length direction of the tube body 2. A thread is provided at one end of the tube body 2 outside the hole to facilitate the screwing of the nut 3. Rotating the nut 3 puts the entire device in a pre-tightened state. When the surrounding rock 1 is deformed, the purpose of pressure relief is achieved by compressing the elastomer 4.

[0036] In another specific embodiment, a plurality of elastic bodies 4 are provided. The elastic bodies 4 are springs, preferably high-strength springs, and the number is preferably 4-6. The plurality of elastic bodies 4 are evenly arranged around the circumference of the tube body 2 between the two annular pads 5 .

[0037] In another specific embodiment, the outer diameter of the tube body 2 is 40 mm-80 mm, the thickness is 4 mm-8 mm, and the tube body 2 is made of steel.

[0038] In another specific embodiment, the pressure relief anchor pipe also includes a casing 6, which is sleeved on one end of the pipe body 2 extending into the hole, and a conical head 14 is fixedly provided at one end of the casing 6 facing the bottom of the hole. The large end of the conical head 14 is fixedly connected to the casing 6, and the small end faces the bottom of the hole. A plurality of grouting holes 12 are opened on the conical head 14, and a small grouting plug 9 is provided in the annular gap between the casing 6 and the pipe body 2. A large grouting plug 8 is provided on the outer sleeve of the casing 6. The large grouting plug 8 is located on the side of the resistance increasing part facing the bottom of the hole, and the small grouting plug 9 is located on the side of the large grouting plug 8 facing the bottom of the hole. The resistance increasing part is fixedly provided on the casing 6, and the casing 6 can move relative to the pipe body 2 under the action of external force. The small slurry stop plug 9 and the large slurry stop plug 8 are used to prevent the slurry from flowing back from the bottom of the hole to the space where the resistance-enhancing component is located. If the resistance-enhancing component is immersed in the slurry and the slurry solidifies, the resistance-enhancing component will be fixed to the hole wall and the pipe body 2, and no relative displacement can occur when the surrounding rock 1 is deformed, which will affect the pressure relief effect of the second stage.

[0039] The casing 6 provides an installation condition for the resistance-increasing component. After grouting and solidification, the casing 6 and the surrounding rock mass 1 are fixed as an integrated structure. When the surrounding rock mass 1 is deformed, the casing 6 and the resistance-increasing component thereon are driven to move relative to the pipe body 2, or the pipe body 2 is driven to move relative to the casing 6 and the resistance-increasing component thereon, thereby realizing the second stage of pressure relief.

[0040] In another specific embodiment, the outer diameter of the sleeve 6 is 90 mm-140 mm, the thickness is 4 mm-8 mm, and the material of the sleeve 6 is steel.

[0041] In another specific embodiment, the resistance increasing component includes a plurality of resistance increasing units 7 , and the plurality of resistance increasing units 7 are evenly arranged along the length direction and the circumference direction of the tube body 2 , and the resistance increasing units 7 are all fixedly disposed on the sleeve 6 .

[0042] In another specific embodiment, the resistance increasing unit 7 is a steel groove structure with two wings. The resistance increasing unit 7 is in a "U" shape or a "V" shape. The resistance increasing unit 7 passes through the sleeve 6 and is fixed on the sleeve 6. The tips of the two side wings of the resistance increasing unit 7 are in contact with the tube body 2 and the inner wall of the hole respectively.

[0043] In another specific embodiment, a check valve 11 is provided at the end opening of the pipe body 2 to prevent the slurry from flowing back. The check valve 11 is a swing check valve 11, which is suitable for horizontal and vertical pipelines. Its working principle is to move by the pressure generated by the flow of the medium or the pressure of the valve disc itself. Here, the valve disc rotates mainly by the pressure impact of the slurry flow; when the grouting is completed, due to the gravity of the valve disc, there is also a spring component at the connection of the rocker, and the channel will be closed when there is no liquid pressure.

[0044] In another specific embodiment, the outer wall of the pipe body 2 on the side of the small slurry stop plug 9 facing the bottom of the hole and the outside of the check valve 11 are covered with an isolation layer 10. The adhesion between the isolation layer 10 and the slurry is smaller than the adhesion between the outer wall of the pipe body 2 and the check valve 11 and the slurry. The isolation layer 10 is made of a grease coating or a wrapping film. The isolation layer 10 and the check valve 11 are bonded together with glue. The adhesion between the isolation layer 10 and the solidified slurry, the pipe body 2 and the check valve 11 is not strong. When the pipe body 2 is subjected to a large force, the pipe body 2 and the slurry can be separated, thereby realizing the second pressure relief process.

[0045] In another specific embodiment, the small slurry stopper 9 and the large slurry stopper 8 are both made of high-strength synthetic rubber, and are both truncated cone-shaped structures with a center hole. The diameter of the center hole of the small slurry stopper 9 is just enough to be mounted on the outer wall of the tube body 2, and the diameter of the center hole of the large slurry stopper 8 is just enough to be mounted on the outer wall of the sleeve 6.

[0046] In another specific embodiment, a sealing structure is disposed between the end of the sleeve 6 facing the orifice and the tube body 2 , and the sealing structure is an annular sealing plate 15 .

[0047] In another specific embodiment, the resistance increasing unit 7 has elastic deformation capability. When the resistance increasing unit 7 is assembled, the resistance increasing unit 7 applies a prestress to the tube body 2. The magnitude of the prestress is determined according to the designed pressure-releasing capacity. The greater the required pressure-releasing capacity, the greater the corresponding prestress.

[0048] Figure 6 It is a force analysis diagram of a single resistance increasing unit 7, in which f1 is the friction force of a single resistance increasing unit 7 on the tube body 2, f1' is the friction force of a single tube body 2 on the resistance increasing unit 7, and f1 and f1' are a pair of interaction forces. The resistance increasing unit 7 has elastic deformation capability. When the resistance increasing unit 7 is installed, an assembly stress σ is applied to the tube body 2 and the resistance increasing unit 7 produces a certain elastic deformation. The size of σ is determined according to the designed pressure relief capability. Figure 7 is the force analysis diagram of the overall resistance increasing unit 7 and the pipe body 2. The force of the surrounding rock 1 stress acting on a single anchor pipe is P, and the maximum friction force that the overall resistance increasing unit 7 can provide is When P is greater than When the resistance increasing unit 7 is relatively displaced relative to the tube body 2, the second stage of pressure release begins. The positive pressure that the tube body 2 can provide to a single resistance increasing unit 7 is The expression is: The maximum friction force that the overall resistance increasing unit 7 can provide Wherein, N1 is the normal pressure exerted on the pipe body 2 by the prefabricated and installed single resistance increasing unit 7;

[0049] F1 is the positive pressure provided by the tube body 2 to the single resistance increasing unit 7;

[0050] S1 is the contact area between a single resistance increasing unit 7 and the tube body 2;

[0051] μ is the dynamic friction coefficient between the contact surface of the resistance increasing unit 7 and the tube body 2;

[0052] It is the maximum friction force that all the resistance increasing units 7 can provide.

[0053] like Figure 8As shown, the pressure relief principle of the pressure relief anchor pipe of the invention is as follows: the AB section is the stage of applying the preload force of the anchor pipe, the preload force is applied to the anchor pipe by tightening the nut 3, the pipe body 2 generates initial prestress and undergoes slight elastic deformation, after the anchor pipe is grouting and anchored, the surrounding rock 1 just deforms, and the anchor pipe provides weak rigid support for the surrounding rock 1; when the force on the anchor pipe increases, the anchor pipe enters the BC section, i.e., the first stage of the pressure relief process, the elastic body 4 (a high-strength spring is used in this embodiment) is compressed and deformed, and the deformation energy of the surrounding rock 1 is initially released; the stress of the surrounding rock 1 continues to increase, and then the CD section, i.e., the rapid resistance increase stage of the anchor pipe, is entered; affected by the construction or mining disturbance, the pressure of the surrounding rock 1 increases, and the surrounding rock 1 continues to deform. When the pressure of the surrounding rock 1 reaches the maximum pressure relief resistance of the anchor pipe, i.e., f max , the anchor pipe enters the DE section, i.e., the second stage of the pressure-releasing process of the anchor pipe. At this time, the support force provided by the anchor pipe to the surrounding rock 1 is the pressure-releasing constant resistance, the resistance-increasing unit 7 is displaced relative to the pipe body 2, and the deformation energy of the surrounding rock 1 is greatly released, thereby keeping the surrounding rock 1 relatively stable; if the deformation of the surrounding rock 1 continues to increase, when the front end of the pipe body 2 slides to the resistance-increasing unit 7, the anchor pipe is subjected to the force and enters the EF section, i.e., the controlled pressure-releasing stage of the anchor pipe. At this time, the stress of the surrounding rock 1 will be further released, but the support resistance provided to the surrounding rock 1 will be gradually reduced; finally, as the tension of the anchor pipe further increases, it enters the FG section, i.e., the failure and damage stage of the anchor pipe. At this time, the deformation of the surrounding rock 1 exceeds the pressure-releasing limit capacity of the pressure-releasing anchor pipe, and the casing 6 and the pipe body 2 slip and fail.

[0054] The construction method is as follows:

[0055] (1) Before anchor pipe construction, carefully check whether the hollow cavity of the pipe body 2, the casing 6, the grouting hole 12 and other parts are unobstructed. If there are foreign objects blocking them, they should be cleaned up in time. Select the hole position and drilling angle according to the design requirements and make markings. The drilling spacing should be in accordance with the design requirements or the requirements of the on-site supervision. At the same time, the grouting materials need to be prepared;

[0056] (2) The drilling rig is in place. When the drilling rig drives the drill rod to drill to the predetermined depth, the drilling rig and drill rod are removed. After the hole is formed, the prefabricated anchor pipe is placed in the hole.

[0057] (3) Connect high-pressure air to the tail end of the anchor pipe to blow away debris in the hollow cavity of the anchor pipe, the casing 6, and the grouting hole 12. Then check whether the grouting equipment is complete and normal. After the equipment is normal, connect the tail end of the anchor pipe to the grouting pump through the quick grouting joint, then start the mortar mixer, manually prepare the grouting material according to the proportion, and then input it into the mixer for mixing with water. After mixing evenly, input it into the grouting pump. When grouting, keep the grouting high-pressure pipe straight. The entire grouting process must be continuously injected without flow and completed in one go;

[0058] (4) The grouting volume is determined according to the pressure of the grouting pump or the mortar consumption rate of the mortar mixer. The grouting pressure should be controlled according to the design value. The initial grouting pressure is generally between 0.5-1.5MPa. When the grouting is full and the pressure reaches the design value, stop grouting;

[0059] (5) Dismantle the grouting equipment and clean and tidy up the grouting pipelines and equipment in time. Do not knock, collide or apply any other load before the slurry is finally set.

[0060] (6) After the slurry in the borehole solidifies and reaches a certain strength, the annular pad 5, high-strength spring and nut 3 are installed in sequence on the tail end of the pipe body 2 at the borehole mouth, and the nut 3 is tightened to the designed preload of the anchor pipe.

[0061] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A pressure relief anchor pipe, characterized in that: The invention comprises a tube body, an end elastic member and a resistance-increasing member, wherein one end of the tube body is used to extend into a hole, and the other end is located outside the hole, and the hole is formed in the surrounding rock, the end elastic member is arranged on the tube body outside the hole, and one end of the end elastic member is used to transmit elastic force to the surrounding rock, and the other end can transmit elastic force to the tube body, the resistance-increasing member is arranged between the tube body in the hole and the inner wall of the hole, the resistance-increasing member is in contact with the outer wall of the tube body and the inner wall of the hole, and the resistance-increasing member can move relative to the tube body and generate friction when subjected to stress applied by deformation of the surrounding rock; the invention also comprises a sleeve, the sleeve is sleeved on the end of the tube body extending into the hole, a conical head is fixedly arranged on one end of the sleeve facing the bottom of the hole, the large end of the conical head is fixedly connected to the sleeve, and the small end faces the bottom of the hole, and the conical head A plurality of grouting holes are opened on it, a small grouting plug is provided in the annular gap between the casing and the pipe body, a large grouting plug is provided on the outer sleeve of the casing, the large grouting plug is located on the side of the resistance increasing member facing the bottom of the hole, the small grouting plug is located on the side of the large grouting plug facing the bottom of the hole, the resistance increasing member is fixedly arranged on the casing, and the casing can move relative to the pipe body under the action of external force; the resistance increasing member includes a plurality of resistance increasing units, and the plurality of resistance increasing units are uniformly arranged along the length direction and the circumference direction of the pipe body, and the resistance increasing units are all fixedly arranged on the casing; the resistance increasing unit is a groove structure with two wings made of steel, the resistance increasing unit is in a "U" shape or a "V" shape, the resistance increasing unit passes through the casing and is fixed on the casing, and the two side wing tips of the resistance increasing unit are respectively in contact with the pipe body and the inner wall of the hole.

2. The pressure relief anchor pipe according to claim 1, characterized in that: The end elastic member includes two annular pads, an elastomer and a nut. The two annular pads are both sleeved on the tube body outside the hole. There is a gap between the two annular pads. The elastomer is clamped between the two annular pads. One annular pad is arranged close to the hole mouth and rests on the surrounding rock at the hole mouth. The nut is threadedly connected to the tube body on the side of the other annular pad away from the elastomer. Rotating the nut can put the elastomer in a compressed state.

3. The pressure relief anchor pipe according to claim 2, characterized in that: A plurality of the elastic bodies are provided, and the elastic bodies are springs. The plurality of the elastic bodies are evenly arranged between the two annular gaskets around the circumference of the tube body.

4. The pressure relief anchor pipe according to claim 1, characterized in that: A check valve is arranged at the opening at the end of the tube body.

5. The pressure relief anchor pipe according to claim 4, characterized in that: The outer wall of the pipe body on the side of the small slurry stopper facing the bottom of the hole and the outside of the check valve are covered with an isolation layer, and the bonding force between the isolation layer and the slurry is smaller than the bonding force between the outer wall of the pipe body and the check valve and the slurry.

6. The pressure relief anchor pipe according to claim 1, characterized in that: A sealing structure is arranged between one end of the sleeve facing the orifice and the tube body.

7. The pressure relief anchor pipe according to claim 1, characterized in that: The resistance increasing unit has elastic deformation capability, and when the resistance increasing unit is assembled, the resistance increasing unit applies a prestress to the tube body.

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