Shaft rockburst-resistant energy-releasing supporting structure and construction method

Abstract

The invention belongs to the technical field of vertical shafts, and provides a shaft rockburst-resistant energy-releasing supporting structure and a construction method.The shaft rockburst-resistant energy-releasing supporting structure comprises an energy-releasing anchor rod, the energy-releasing anchor rod is used for being arranged in a shaft surrounding rock drill hole, and the energy-releasing anchor rod comprises a rod body, anchoring parts arranged on the rod body at intervals and a stirring part arranged at the first end of the rod body; the fixing assembly is arranged at the second end of the rod body; and the protective net is arranged on the inner side of the fixing assembly. The energy-releasing yielding structure has the beneficial effects that power energy-releasing yielding is achieved while high drawing force is kept through the energy-releasing anchor rods, the protective net can effectively prevent rock debris from being ejected and keep the integrity of the protective net, the tie bars are connected with the energy-releasing anchor rods and evenly distribute supporting force, and the jetting reinforcing layer provides early supporting and enhances the strength and toughness of the whole structure. The device can adapt to complex geological conditions and rockburst stress environments of the ultra-deep shaft, and provides reliable safety guarantee for construction and operation of the ultra-deep shaft.

Description

Technical Field

[0001] The present application belongs to the technical field of vertical shafts, and specifically relates to a shaft anti-rock burst energy release support structure and a construction method. Background Art

[0002] In the field of underground engineering, especially in the construction of ultra-deep wells, rock burst is an extremely serious and complex geological disaster. With the continuous development of underground resources and the extension of engineering construction to deeper strata, the rock burst problem faced by ultra-deep wells has become more and more prominent.

[0003] Rockbursts occur due to the sudden release of internal energy in underground rock mass under high stress. This energy release can cause rock fracture and ejection, causing huge impact and damage to the wellbore and its support structure. Traditional support methods have many limitations in dealing with rockbursts in ultra-deep wellbores. On the one hand, traditional support structures often focus on providing static support forces and lack effective control and drainage mechanisms for rockburst energy release. For example, ordinary anchor rods and metal mesh support systems cannot absorb and release energy in a timely and effective manner when rockbursts occur, which easily leads to energy accumulation, and then the support structure fails due to excessive impact force. On the other hand, the existing support structure has poor adaptability to the complex geological conditions and stress environment of ultra-deep wellbores. The rock mass characteristics around ultra-deep wellbores may vary greatly in different strata and regions, including rock strength, joint and fissure distribution, and ground stress magnitude. Traditional support structures are difficult to flexibly adjust according to these changes and cannot meet the requirements for rockburst resistance under different conditions. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] In order to solve the above problems, the first aspect of the present application provides a wellbore anti-rock burst energy release support structure, comprising: An energy-releasing anchor rod, which is used to be arranged in a borehole in the surrounding rock of a wellbore, and comprises a rod body, an anchoring piece arranged at intervals on the rod body, and a stirring piece arranged on a first end of the rod body; A fixing assembly, the fixing assembly being arranged on the second end of the rod body; A protective net, the protective net being arranged inside the fixing assembly; Tie bars, which are arranged on the fixing assembly and are located on a side of the protection net away from the surrounding rock of the wellbore; A reinforcement layer is provided on the surrounding rock of the wellbore, and the reinforcement layer covers the reinforcement bars and the fixing components.

[0006] Optionally, it further includes a first stirring rib and a second stirring rib, wherein the first stirring rib and the second stirring rib are arranged on the outer circumference of a side of the stirring member away from the rod body.

[0007] Optionally, the first stirring rib and the second stirring rib are cross-arranged on the stirring member, and the length of the first stirring rib is smaller than that of the second stirring rib.

[0008] Optionally, anchoring ribs are cross-arranged on the outer circumference of the anchoring piece.

[0009] Optionally, the fixing component includes: A first fixing plate, wherein the first fixing plate is disposed on the second end of the rod body; A second fixing plate, the second fixing plate is disposed on the second end of the rod body and is located on one side of the first fixing plate; A fastener is arranged on the second end of the rod body, and the fastener is located on a side of the second fixing plate away from the first fixing plate.

[0010] Optionally, the protective net is arranged on the inner side of the first fixing plate, and net clips are arranged on both sides of the protective net.

[0011] Optionally, the tensioning rod is arranged on the second fixing plate.

[0012] Optionally, the reinforcement layer includes a concrete layer.

[0013] The second aspect of the present application provides a method for constructing a wellbore rockburst energy release support structure, using a wellbore rockburst energy release support structure according to any of the above technical solutions, comprising the following steps: S1, drilling the surrounding rock of the wellbore and placing the energy-releasing anchor rod in the borehole to form a stable anchoring system; S2, determining the mesh shape and size of the protection net according to the rock burst intensity and the rock particle size, and installing the protection net on the second end of the rod body through the fixing assembly; S3, connecting the tensioning bar to the second fixing plate of the wellbore anti-rock burst energy release support structure, and detecting the tension after installation; S4. Spray the reinforcement layer inside the surrounding rock of the wellbore, and determine the spraying thickness based on the rock burst risk assessment and the mechanical properties of the surrounding rock.

[0014] Optionally, in S2, after the protective net is installed, two sides of the protective net are connected by a net clip.

[0015] Beneficial Effects In the embodiments of the present invention, a wellbore anti-rockburst energy release support structure and construction method are provided. The energy release anchor rods can achieve dynamic release while maintaining high pullout force. The protective net can effectively block the ejection of rock debris and maintain its own integrity. The tensioning bars connect the energy release anchor rods and evenly distribute the support force. The injection reinforcement layer provides early support and enhances the strength and toughness of the overall structure. This device can adapt to the complex geological conditions and rockburst stress environment of ultra-deep wellbores, and provide reliable safety guarantees for the construction and operation of ultra-deep wellbores. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of the wellbore anti-rock burst energy release support structure of the present application; Figure 2 This is a diagram of the energy-release anchor structure of the wellbore anti-rockburst energy-release support structure of the present application; Figure 3 This is a main structural diagram of the wellbore anti-rock burst energy release support structure of the present application; Figure 4 A side structural diagram of the wellbore anti-rock burst energy release support structure of the present application; Figure 5 This is a structural diagram of the anchor and stirring member of the wellbore anti-rock burst energy release support structure of the present application; Figure 6 This is a flowchart of the construction method of the shaft anti-rock burst energy release support structure of the present application.

[0017] The reference numerals are as follows: 1. Energy release anchor rod; 11. Rod body; 12. Anchor piece; 121. Anchor rib; 13. Stirring piece; 131. First stirring rib; 132. Second stirring rib; 2. Fixing assembly; 21. First fixing plate; 22. Second fixing plate; 23. Fastener; 3. Protective net; 4. Tension bar; 5. Reinforcement layer; 6. Net clamp. DETAILED DESCRIPTION

[0018] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred system or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0019] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0020] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0022] See also Figure 1-5 As shown, according to the first aspect of the present application, a wellbore anti-rock burst energy release support structure is provided, comprising: The energy-releasing anchor rod 1 is used to be arranged in a borehole in the surrounding rock of a wellbore, and the energy-releasing anchor rod 1 comprises a rod body 11, anchoring pieces 12 arranged at intervals on the rod body 11, and a stirring piece 13 arranged on a first end of the rod body 11; A fixing assembly 2, the fixing assembly 2 is arranged on the second end of the rod body 11; A protective net 3, which is arranged inside the fixed component 2; Tie bars 4 are arranged on the fixing assembly 2, and are located on the side of the protection net 3 away from the surrounding rock of the wellbore; The reinforcement layer 5 is arranged on the surrounding rock of the wellbore, and the reinforcement layer 5 covers the reinforcing bars 4 and the fixing components 2 .

[0023] The wellbore anti-rockburst energy release support structure provided in this embodiment includes an energy release anchor rod 1, a fixing assembly 2, a protective net 3, a tie rod 4 and a reinforcement layer 5. The rod body 11 of the energy release anchor rod 1 is made of high-strength alloy material, ensuring that it can withstand huge pressure and tension in a complex wellbore surrounding rock environment. The anchor 12 and the stirring member 13 installed on the rod body 11 can stir the resin roll or cement roll during the installation process, so that the bond between the anchor rod and the inner wall of the borehole is more firm, effectively improving the stability of the support structure.

[0024] The fixing assembly 2 is used to connect the energy release anchor 1, the protection net 3 and the tie rod 4. The fixing assembly 2 is usually made of high-strength metal and has good load-bearing capacity and corrosion resistance. It can firmly fix the protection net 3 on the energy release anchor 1 and fit it on the inner wall of the surrounding rock of the wellbore to prevent the protection net 3 from loosening or falling off under the impact of rock burst. At the same time, the fixing assembly 2 provides a stable connection point for the tie rod 4, so that the tie rod 4 can effectively transfer stress and improve the overall strength of the support structure.

[0025] The protective net 3 is arranged on the fixed component 2 and plays an important protective role. The protective net 3 is usually woven from high-strength and corrosion-resistant steel wires and has good toughness and tensile properties. The size and shape of the mesh are determined based on the results of the previous analysis of the rock burst intensity and the rock particle size. It can effectively block the ejection of rock debris and protect the safety of construction personnel and equipment.

[0026] The tie rod 4 is arranged on the fixing assembly 2, and is located on the side of the protection net 3 away from the surrounding rock of the wellbore. The tie rod 4 is usually made of high-strength steel bars or steel strands, and has good tensile properties. When a rock burst occurs, the tie rod 4 can connect the energy-releasing anchor rods 1 together to form an integral support structure, effectively transfer stress, and avoid failure of the support structure due to excessive local stress. The surface of the tie rod 4 is treated with anti-corrosion to improve its corrosion resistance in a humid wellbore environment.

[0027] The reinforcement layer 5 is arranged on the surrounding rock of the shaft, covering the tie rods 4 and the fixing components 2, and providing additional protection for the entire support structure. The reinforcement layer 5 is usually made of concrete or other high-strength materials, and has good compression and shear resistance. It can enhance the overall stability of the support structure and improve its rock burst resistance. The thickness of the reinforcement layer 5 is determined based on the rock burst risk assessment and the mechanical properties of the shaft surrounding rock. In areas with high rock burst risk, the thickness of the reinforcement layer 5 is larger to provide stronger protection.

[0028] When using it, first of all, before construction, a detailed geological survey of the surrounding rock of the wellbore is required, and professional instruments and equipment are used to measure parameters such as the size of ground stress, rock strength, and joint and fissure distribution. Based on these survey results and combined with the rock burst risk assessment model, the key parameters such as the length and diameter required for the energy release anchor 1 are accurately calculated. At the same time, the layout of the drilling holes is planned according to the geological characteristics of different areas. In areas with more broken surrounding rocks, the drilling holes are appropriately increased; in relatively stable areas, the drilling spacing can be reasonably adjusted to save costs and improve construction efficiency.

[0029] Perform drilling operations. Use advanced drilling equipment to ensure the accuracy and stability of its drill bit. During the drilling process, strictly control the depth of the borehole so that the depth error with the design requirements is controlled within a very small range. For example, for a borehole with a design depth of 5 meters, the actual depth error should not exceed ±0.1 meters. At the same time, use inclinometers and other equipment to monitor the verticality of the borehole in real time to ensure that the inclination of the borehole does not exceed the specified value, which should generally be controlled within 1°. When the borehole reaches the predetermined depth, the inside of the borehole needs to be cleaned to remove floating dust and loose rock debris on the hole wall to create good conditions for the subsequent installation of resin or cement rolls.

[0030] When placing resin or cement rolls in the borehole, pay attention to the placement and quantity of the rolls. According to the diameter and depth of the anchor hole, accurately calculate the amount of rolls required to ensure the anchoring effect. After the energy-releasing anchor 1 is inserted into the hole, start the installation equipment. The installation equipment drives the energy-releasing anchor 1 to rotate in the hole. The anchor 12 and the stirring member 13 can stir the rolls under the drive of the installation equipment. The rotation speed is generally controlled at 200-300 revolutions per minute. The rotation time depends on the type of roll and the situation in the hole, usually 30-60 seconds, to ensure that the roll can evenly fill the borehole and fully bond with the hole wall, so that the energy-releasing anchor 1 forms a stable anchoring system with the surrounding rock through the roll. The rod body 11 is made of chromium-molybdenum steel, which has high strength and good toughness, so that it can absorb and release energy when it is impacted by rock burst. For example, when the energy inside the surrounding rock is suddenly released to produce an impact, the rod body 11 will deform to a certain extent, converting part of the impact energy into its own elastic potential energy, and at the same time, through reasonable stress distribution, transferring the remaining energy to the anchor 12 and the surrounding rock mass, thereby effectively reducing the direct impact force on the support structure. After the energy release anchor 1 is installed, the fixing assembly 2 is installed on its second end.

[0031] The fixing assembly 2 can fix the protective net 3, and the protective net 3 is made of high-strength and corrosion-resistant steel wire material. The shape and size of the mesh are determined according to the results of the previous analysis of the rock burst strength and the rock mass particle size. In areas with high rock burst risk and high possibility of rock debris ejection, a diamond mesh and a smaller size protective net 3 is used, which can more effectively block debris. The grid side length of the protective net 3 can be controlled to be 3-5 cm. In areas with relatively low risks, a rectangular mesh and a properly enlarged size protective net 3 is used, which can not only meet the protection requirements, but also reduce material costs and construction difficulties. The grid side length of the protective net 3 can be adjusted to 5-8 cm. When fixing the protective net 3, it is necessary to ensure that it is connected to the energy release anchor rod 1 and fits tightly on the inner wall of the surrounding rock of the wellbore. The protective net 3 can be tied to the rod body 11 with fine iron wire. The spacing between the tying points should not be too large, generally controlled to be 20-30 cm. The edge of the protective net 3 can increase the thickness and strength of the frame to prevent tearing during rock burst impact or long-term use. After the protection net 3 is installed, both sides thereof are fixedly connected so that it will not loosen or fall off under the impact of rock burst, thereby enhancing the integrity and stability of the protection net 3.

[0032] The tie bars 4 are installed. The tie bars 4 are made of high-strength steel bars or steel strands. The diameter of the tie bars 4 is determined according to the stress analysis of the support structure and the rock burst risk assessment results. In the area with greater stress, the diameter of the tie bars 4 can be appropriately increased. The anti-corrosion treatment of the surface of the tie bars 4 adopts methods such as hot-dip galvanizing or coating with anti-corrosion paint to improve its corrosion resistance in a humid wellbore environment. The tie bars 4 are installed on the fixed component 2 to ensure that the tension of the tie bars 4 is moderate. Too tight may cause uneven stress on the energy release anchor rod 1 or affect its deformation energy release function; too loose will not effectively transfer stress. After the installation is completed, a special tension detection instrument can be used to detect the tension of the tie bars 4 to ensure that the tension of the tie bars 4 meets the requirements. When a rock burst occurs, the tie bars 4 can quickly connect the energy release anchor rods 1 into a whole, effectively transfer stress, make the stress of the entire support structure more uniform, and avoid local excessive stress causing the support structure to fail. At the same time, the tie bars 4 themselves can resist the impact of rock bursts by virtue of their high strength characteristics, further improving the stability of the support structure.

[0033] Install the reinforcement layer 5. When spraying the reinforcement layer 5, professional spraying equipment is required to adjust the spraying angle and distance. The spraying angle is generally controlled at 75°-90°, and the spraying distance is 0.8-1.5 meters. Ensure that the sprayed reinforcement layer 5 can evenly cover the inner surface of the wellbore surrounding rock and wrap the protection net 3 and the reinforcement 4. Determine the spraying thickness based on the rock burst risk assessment and the mechanical properties of the wellbore surrounding rock. In areas with high rock burst risks, the spraying thickness can reach 10-15 cm; in areas with low risks, the thickness can be controlled at 5-8 cm. The sprayed reinforcement layer 5 can provide timely protection for the protection net 3 and the reinforcement 4.

[0034] The energy release anchor rod 1 can achieve dynamic release and compression while maintaining high pull-out force. The protective net 3 can effectively block the ejection of rock debris and maintain its own integrity. The tie rod 4 connects the energy release anchor rods 1 and evenly distributes the support force. The spray reinforcement layer 5 provides early support and enhances the strength and toughness of the overall structure. This device can adapt to the complex geological conditions and rock burst stress environment of ultra-deep wells, and provide reliable safety guarantees for the construction and operation of ultra-deep wells.

[0035] The stirring member 13 further includes a first stirring rib 131 and a second stirring rib 132 . The first stirring rib 131 and the second stirring rib 132 are disposed on the outer circumference of a side of the stirring member 13 away from the rod body 11 .

[0036] The first stirring rib 131 and the second stirring rib 132 are cross-arranged on the stirring member 13 , and the length of the first stirring rib 131 is smaller than that of the second stirring rib 132 .

[0037] In this technical solution, the first stirring rib 131 and the second stirring rib 132 are located on the outer circumference of the side of the stirring member 13 away from the rod body 11. When the stirring member 13 rotates to stir the resin roll or cement roll injected into the borehole, the first stirring rib 131 and the second stirring rib 132 can increase the range and intensity of stirring, so that the roll can fill the borehole more evenly, thereby further enhancing the bonding force between the anchor rod and the surrounding rock.

[0038] The first stirring ribs 131 and the second stirring ribs 132 are cross-arranged on the stirring member 13, so that the stirring is more complete, and the resin or cement rolls can be effectively prevented from being partially uneven in the borehole. At the same time, the first stirring ribs 131 and the second stirring ribs 132 of different lengths cooperate with each other to achieve multi-level stirring, improve the efficiency and quality of stirring, and form a stable anchoring system.

[0039] Anchoring ribs 121 are cross-arranged on the outer circumference of the anchoring member 12 .

[0040] In this technical solution, the cross-arranged anchor bars 121 on the outer circumference of the anchor 12 can effectively prevent the anchor 12 from slipping in the borehole when the energy-releasing anchor rod 1 is subjected to the huge stress generated by rock burst, ensuring that the anchor rod is tightly combined with the surrounding rock, thereby improving the stability of the entire support structure. The cross-arranged anchor bars 121 can interact with the surrounding rock from different directions, so that the anchor 12 can obtain a good anchoring effect in all directions. This multi-directional anchoring force can better adapt to the complex stress state of the wellbore surrounding rock and improve the support structure's resistance to the impact of rock bursts in different directions.

[0041] In the actual construction process, the presence of the anchor bar 121 makes it easier for the anchor 12 to fully combine with the resin or cement roll. The anchor bar 121 can be embedded in the roll, increasing the contact area between the anchor 12 and the roll and improving the bonding force. At the same time, after the roll solidifies, the anchor bar 121 can also enhance the connection strength with the inner wall of the borehole, further improving the anchoring effect of the anchor rod.

[0042] The fixing assembly 2 comprises: A first fixing plate 21, the first fixing plate 21 is disposed on the second end of the rod body 11; A second fixing plate 22, which is disposed on the second end of the rod body 11 and is located on one side of the first fixing plate 21; The fastener 23 is disposed on the second end of the rod body 11 . The fastener 23 is located on a side of the second fixing plate 22 away from the first fixing plate 21 .

[0043] In this technical solution, the first fixing plate 21 is threadedly connected to the second end of the rod body 11. The second fixing plate 22 is installed on one side of the first fixing plate 21 through a fastener 23. The second end of the rod body 11 is provided with a thread. The fastener 23 is a nut, which is used to tightly fix the first fixing plate 21, the second fixing plate 22 and the protective net 3 together.

[0044] After the second fixing plate 22 is installed on the rod body 11 , it is necessary to ensure that the angle and position of the second fixing plate 22 are installed accurately.

[0045] The second fixing plate 22 is an L-shaped structure, and a hole is provided at the bottom thereof, and the hole is used to connect the tie rod 4 .

[0046] The protection net 3 is arranged inside the first fixing plate 21 , and net clips 6 are arranged on both sides of the protection net 3 .

[0047] In this technical solution, the protective net 3 is located on the inner side of the first fixed plate 21 and is tightly attached to the inner wall of the surrounding rock of the wellbore. The first fixed plate 21 can provide support and restriction to the protective net 3 to prevent the protective net 3 from being displaced or deformed under the impact of rock burst. The net clamps 6 arranged on both sides of the protective net 3 further enhance the stability of the protective net 3. The net clamps 6 are usually made of high-strength metal materials and have good clamping force and durability. The net clamps 6 can tightly clamp the edges on both sides of the protective net 3 to prevent the protective net 3 from escaping from the fixed assembly 2. When a rock burst occurs, the net clamps 6 can withstand huge impact forces, ensuring that the protective net 3 always remains in the correct position, playing its role in blocking the ejection of rock debris, and improving the overall reliability of the support structure.

[0048] The tie rod 4 is disposed on the second fixing plate 22 .

[0049] In this technical solution, the tie bars 4 are installed on the second fixing plate 22 through the pulling holes, and the second fixing plate 22 can provide reliable support for the tie bars 4. When a rock burst occurs, the tie bars 4 can quickly connect the energy-releasing anchor rods 1 together to form an integral support structure, and can also effectively transfer stress, making the force of the entire support structure more uniform. In addition, the arrangement of the tie bars 4 on the second fixing plate 22 is also convenient for construction and installation. After installing the fixing assembly 2, the construction personnel can fix the tie bars 4 in series on the second fixing plate 22, thereby improving the construction efficiency. At the same time, this arrangement also makes the position of the tie bars 4 clearer, which is convenient for later inspection and maintenance.

[0050] The reinforcement layer 5 includes a concrete layer.

[0051] In this technical solution, the reinforcement layer 5 includes a concrete layer. Before construction, the raw materials of the concrete layer need to be tested. The strength grade of cement needs to meet the requirements. The particle size of crushed stone and sand should be moderate and well graded. The amount of accelerator added is precisely controlled according to the on-site construction conditions and the risk of rock burst. In areas with high humidity and high risk of rock burst, the amount of accelerator is appropriately increased to accelerate the setting speed of concrete and improve the early strength. The model and addition ratio of water reducer are optimized according to the type of cement and aggregate characteristics. For example, for silicate cement, high-efficiency water reducer can be selected, and the addition ratio is generally 0.5% - 1.5% of the cement mass, which improves the strength and durability of concrete by reducing the water-cement ratio. The type (such as steel fiber or polypropylene fiber) and length of fiber reinforcement materials are determined according to the stress characteristics of concrete and the requirements for rock burst protection. In areas where it is necessary to improve the toughness of concrete, steel fiber can be used, and the fiber length is generally 20-40 mm; in areas where higher durability requirements are required, polypropylene fiber can be used, and the fiber length is 10-20 mm. After the raw materials of the concrete layer are mixed, they are sprayed onto the inner surface of the surrounding rock of the shaft through professional equipment to cover the protective net 3 and the reinforcement 4, forming an overall support system to enhance the support.

[0052] See also Figure 6 As shown, the second aspect of the present application provides a method for constructing a wellbore anti-rockburst energy release support structure, using the wellbore anti-rockburst energy release support structure in any embodiment of the first aspect, comprising the following steps: S1, drilling the surrounding rock of the wellbore and placing the energy-releasing anchor rod 1 in the borehole to form a stable anchoring system; Specifically, before construction, a detailed geological survey of the surrounding rock of the wellbore is required, and professional instruments and equipment are used to measure parameters such as the size of ground stress, rock strength, and distribution of joints and fissures. Based on these survey results and combined with the rock burst risk assessment model, key parameters such as the length and diameter required for the energy release anchor 1 are accurately calculated. At the same time, the layout of the drilling holes is planned according to the geological characteristics of different areas. In areas with more broken surrounding rocks, the drilling holes are appropriately increased; in relatively stable areas, the drilling spacing can be reasonably adjusted to save costs and improve construction efficiency.

[0053] Perform drilling operations. Use advanced drilling equipment to ensure the accuracy and stability of its drill bit. During the drilling process, strictly control the depth of the borehole so that the depth error with the design requirements is controlled within a very small range. For example, for a borehole with a design depth of 5 meters, the actual depth error should not exceed ±0.1 meters. At the same time, use inclinometers and other equipment to monitor the verticality of the borehole in real time to ensure that the inclination of the borehole does not exceed the specified value, which should generally be controlled within 1°. When the borehole reaches the predetermined depth, the inside of the borehole needs to be cleaned to remove floating dust and loose rock debris on the hole wall to create good conditions for the subsequent installation of resin or cement rolls.

[0054] When placing resin or cement rolls in the borehole, pay attention to the placement and quantity of the rolls. According to the diameter and depth of the anchor hole, accurately calculate the amount of rolls required to ensure the anchoring effect. After the energy-releasing anchor 1 is inserted into the hole, start the installation equipment. The installation equipment drives the energy-releasing anchor 1 to rotate in the hole. The anchor 12 and the stirring member 13 can stir the rolls under the drive of the installation equipment. The rotation speed is generally controlled at 200-300 revolutions per minute. The rotation time depends on the type of roll and the situation in the hole, usually 30-60 seconds, to ensure that the roll can evenly fill the borehole and fully bond with the hole wall, so that the energy-releasing anchor 1 forms a stable anchoring system with the surrounding rock through the roll. The rod body 11 is made of chromium-molybdenum steel, which has high strength and good toughness, so that it can absorb and release energy when it is impacted by rock burst. For example, when the energy inside the surrounding rock is suddenly released to produce an impact, the rod body 11 will deform to a certain extent, converting part of the impact energy into its own elastic potential energy, and at the same time, through reasonable stress distribution, transferring the remaining energy to the anchor 12 and the surrounding rock mass, thereby effectively reducing the direct impact force on the support structure. After the energy release anchor 1 is installed, the fixing assembly 2 is installed on its second end.

[0055] S2, determine the mesh shape and size of the protection net 3 according to the rock burst intensity and the rock particle size, and install the protection net 3 on the second end of the rod body 11 through the fixing component 2; Specifically, the fixing assembly 2 can fix the protective net 3, and the protective net 3 is made of high-strength and corrosion-resistant steel wire material. The shape and size of the mesh are determined according to the results of the previous analysis of the rock burst strength and the rock mass particle size. In areas with high rock burst risk and high possibility of rock debris ejection, a protective net 3 with a diamond mesh and a smaller size is used, which can more effectively block debris. The grid side length of the protective net 3 can be controlled to be 3-5 cm. In areas with relatively low risks, a protective net 3 with a rectangular mesh and an appropriately increased size is used, which can not only meet the protection requirements, but also reduce material costs and construction difficulties. The grid side length of the protective net 3 can be adjusted to 5-8 cm. When fixing the protective net 3, it is necessary to ensure that it is connected to the energy release anchor rod 1 and fits tightly on the inner wall of the surrounding rock of the wellbore. The protective net 3 can be tied to the rod body 11 with a thin iron wire. The spacing between the tying points should not be too large, generally controlled to be 20-30 cm. The edge of the protective net 3 can increase the thickness and strength of the frame to prevent tearing during rock burst impact or long-term use. After the protection net 3 is installed, both sides thereof are fixedly connected so that it will not loosen or fall off under the impact of rock burst, thereby enhancing the integrity and stability of the protection net 3.

[0056] S3, connecting the tensioning bar 4 to the second fixing plate 22 of the wellbore anti-rock burst energy release support structure, and detecting the tension after installation; Specifically, the tie rod 4 is installed. The tie rod 4 uses high-strength steel bars or steel strands, and its diameter is accurately determined according to the stress analysis of the support structure and the rock burst risk assessment results. In the area with greater stress, the diameter of the tie rod 4 can be appropriately increased. The anti-corrosion treatment of the surface of the tie rod 4 adopts methods such as hot-dip galvanizing or coating with anti-corrosion paint to improve its corrosion resistance in a humid wellbore environment. The tie rod 4 is installed on the fixed component 2, and the tension of the tie rod 4 must be moderate. Too tight may cause uneven stress on the energy release anchor rod 1 or affect its deformation energy release function; too loose will not effectively transfer stress. After the installation is completed, a special tension detection instrument can be used to detect the tension of the tie rod 4 to ensure that the tension of the tie rod 4 meets the requirements. When a rock burst occurs, the tie rod 4 can quickly connect the energy release anchor rods 1 into a whole, effectively transfer stress, make the stress of the entire support structure more uniform, and avoid local excessive stress causing failure of the support structure. At the same time, the tie rod 4 itself can resist the impact of rock burst due to its high strength, further improving the stability of the support structure.

[0057] S4. Spray a reinforcement layer 5 inside the surrounding rock of the wellbore, and determine the spraying thickness based on the rock burst risk assessment and the mechanical properties of the surrounding rock.

[0058] Specifically, the raw materials of the concrete layer need to be tested before construction. The strength grade of cement needs to meet the requirements. The particle size of crushed stone and sand should be moderate and well graded. The amount of accelerator added should be precisely controlled according to the on-site construction conditions and the risk of rock burst. In areas with high humidity and high risk of rock burst, the amount of accelerator should be appropriately increased to accelerate the setting speed of concrete and improve the early strength. The model and addition ratio of water reducer should be optimized according to the type of cement and aggregate characteristics. For example, for silicate cement, high-efficiency water reducer can be selected, and the addition ratio is generally 0.5% - 1.5% of the cement mass, which can improve the strength and durability of concrete by reducing the water-cement ratio. The type (such as steel fiber or polypropylene fiber) and length of fiber reinforcement materials are determined according to the stress characteristics of concrete and the requirements for rock burst protection. In areas where the toughness of concrete needs to be improved, steel fibers can be used, and the fiber length is generally 20-40 mm; in areas where durability requirements are high, polypropylene fibers can be used, and the fiber length is 10-20 mm. After the raw materials of the reinforcement layer 5 are mixed, they are sprayed onto the inner surface of the surrounding rock of the wellbore through professional equipment to cover the protective net 3 and the reinforcement 4 to form an overall support system to enhance the support. When spraying the reinforcement layer 5, adjust the spray angle and distance. The spray angle is generally controlled at 75°-90°, and the spray distance is 0.8-1.5 meters. Ensure that the reinforcement layer 5 after spraying can evenly cover the inner surface of the surrounding rock of the wellbore and wrap the protective net 3 and the reinforcement 4. Determine the spray thickness based on the rock burst risk assessment and the mechanical properties of the surrounding rock of the wellbore. In areas with high rock burst risks, the spray thickness can reach 10-15 cm; in areas with low risks, the thickness can be controlled at 5-8 cm. The sprayed reinforcement layer 5 can provide timely protection for the protective net 3 and the reinforcement 4.

[0059] The energy release anchor rod 1 can achieve dynamic release and compression while maintaining high pull-out force. The protective net 3 can effectively block the ejection of rock debris and maintain its own integrity. The tie rod 4 connects the energy release anchor rods 1 and evenly distributes the support force. The spray reinforcement layer 5 provides early support and enhances the strength and toughness of the overall structure. This device can adapt to the complex geological conditions and rock burst stress environment of ultra-deep wells, and provide reliable safety guarantees for the construction and operation of ultra-deep wells.

[0060] Optionally, in S3 , after the protective net 3 is installed, two sides of the protective net 3 are connected by a net clamp 6 .

[0061] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A wellbore anti-rock burst energy release support structure, characterized in that: include: An energy-releasing anchor rod (1), the energy-releasing anchor rod (1) being used for being arranged in a borehole in the surrounding rock of a wellbore, the energy-releasing anchor rod (1) comprising a rod body (11), anchoring pieces (12) arranged at intervals on the rod body (11), and a stirring piece (13) arranged on a first end of the rod body (11); A fixing assembly (2), wherein the fixing assembly (2) is arranged on the second end of the rod body (11); A protective net (3), the protective net (3) being arranged inside the fixing component (2); Tie bars (4), the tie bars (4) being arranged on the fixing assembly (2), and the tie bars (4) being located on a side of the protection net (3) away from the surrounding rock of the wellbore; A reinforcement layer (5), wherein the reinforcement layer (5) is arranged on the surrounding rock of the wellbore, and the reinforcement layer (5) covers the reinforcement (4) and the fixing assembly (2).

2. The wellbore anti-rock burst energy release support structure according to claim 1 is characterized in that: It also comprises a first stirring rib (131) and a second stirring rib (132), wherein the first stirring rib (131) and the second stirring rib (132) are arranged on the outer circumference of a side of the stirring member (13) away from the rod body (11).

3. The wellbore anti-rock burst energy release support structure according to claim 2 is characterized in that: The first stirring rib (131) and the second stirring rib (132) are cross-arranged on the stirring member (13), and the length of the first stirring rib (131) is smaller than that of the second stirring rib (132).

4. The wellbore anti-rock burst energy release support structure according to claim 1, characterized in that: Anchoring ribs (121) are cross-arranged on the outer circumference of the anchoring piece (12).

5. The wellbore anti-rock burst energy release support structure according to any one of claims 1 to 4, characterized in that: The fixing assembly (2) comprises: A first fixing plate (21), the first fixing plate (21) being arranged on the second end of the rod body (11); A second fixing plate (22), the second fixing plate (22) being arranged on the second end of the rod body (11) and located on one side of the first fixing plate (21); A fastener (23), wherein the fastener (23) is arranged on the second end of the rod body (11), and the fastener (23) is located on a side of the second fixing plate (22) away from the first fixing plate (21).

6. The wellbore anti-rock burst energy release support structure according to claim 5, characterized in that: The protective net (3) is arranged on the inner side of the first fixing plate (21), and net clips (6) are arranged on both sides of the protective net (3).

7. The wellbore anti-rock burst energy release support structure according to claim 5, characterized in that: The tensioning rod (4) is arranged on the second fixing plate (22).

8. The wellbore anti-rock burst energy release support structure according to claim 1, characterized in that: The reinforcement layer (5) comprises a concrete layer.

9. A construction method for a wellbore anti-rock burst energy release support structure, characterized in that: The wellbore anti-rock burst energy release support structure according to any one of claims 1 to 8 comprises the following steps: S1, drilling the surrounding rock of the wellbore and placing the energy-releasing anchor rod (1) in the borehole to form a stable anchoring system; S2, determining the mesh shape and size of the protection net (3) according to the rock burst intensity and the rock mass particle size, and installing the protection net (3) on the second end of the rod body (11) through the fixing component (2); S3, connecting the tensioning bar (4) to the second fixing plate (22) of the wellbore anti-rock burst energy release support structure, and detecting the tension after installation; S4. Spraying the reinforcement layer (5) inside the surrounding rock of the wellbore, and determining the spraying thickness based on the rock burst risk assessment and the mechanical properties of the surrounding rock.

10. The method for constructing a wellbore anti-rockburst energy release support structure according to claim 9, characterized in that: In S2, after the protective net (3) is installed, two sides of the protective net (3) are connected by means of a net clamp (6).

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