High impact toughness anchor net for deep roadway surrounding rock support

Abstract

The utility model relates to a kind of high impact toughness anchor net for deep roadway surrounding rock support, its structure is: steel wire net is by the weft flat needle weaving structure of several steel wires;Each steel wire is by several U-shaped steel wire coils;The U-shaped steel wire coil of each phase row steel wire is sequentially threaded in the same direction and forms steel wire net;Heteromorphic spring is provided on every interval row steel wire, and heteromorphic spring is distributed at intervals. The high impact toughness anchor net not only can bear static load like traditional metal net, more importantly, under the premise that fracture does not occur, by the plastic deformation of itself, the huge energy generated by surrounding rock deformation is absorbed, the integrity of support is maintained, while cooperating with shell, the energy absorption efficiency is improved, the fatigue damage of connecting structure is greatly relieved, so that the long-term service ability of anchor net system under complex geological conditions is comprehensively enhanced.

Description

Technical Field

[0001] This utility model relates to a high impact toughness anchor mesh for supporting the surrounding rock of deep tunnels, belonging to the technical field of protective net reinforcement. Background Technology

[0002] In underground engineering projects such as mining, transportation tunnels, and water conservancy and hydropower, tunnel excavation disrupts the original rock stress balance, leading to a redistribution of surrounding rock stress. This often results in roof collapses, sidewall spalling, and other rock instability phenomena, seriously threatening construction and operational safety. Therefore, developing efficient and reliable tunnel support technology has always been a core issue in the field of geotechnical engineering. Traditional tunnel support methods have mainly gone through the following stages: Initially, passive support systems, represented by wooden supports and steel frames, were commonly used. These structures only passively provide support after the surrounding rock deforms, failing to effectively suppress early deformation and loosening of the surrounding rock. They are ill-suited to complex and variable geological conditions, have limited support effectiveness, and consume a large amount of materials.

[0003] To address this issue, metal mesh was introduced as a necessary surface protection component, forming an "anchor-mesh support" system together with anchor bolts. Early metal meshes were mostly rigid wire mesh or steel mesh, which, while preventing debris from falling, lacked flexibility and ductility. As coal mines in my country have gradually entered deeper mining operations, rock bursts and other dynamic impacts causing damage to the surrounding rock have become increasingly common. When the surrounding rock undergoes significant impact deformation, rigid mesh is highly susceptible to brittle fracture due to stress concentration, losing its protective function and potentially triggering a chain reaction of damage. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a high impact toughness anchor mesh for supporting the surrounding rock of deep tunnels. This high impact toughness anchor mesh can not only withstand static loads like traditional metal mesh, but more importantly, it can absorb the huge energy generated by the deformation of the surrounding rock through its own plastic deformation without breaking, thus maintaining the integrity of the support. At the same time, when used with the outer shell, it improves the energy absorption efficiency and greatly alleviates the fatigue damage of the connection structure, thereby comprehensively enhancing the long-term service capability of the anchor mesh system under complex geological conditions.

[0005] To solve the above problems, the specific technical solution of this utility model is as follows: a high impact toughness anchor mesh for supporting the surrounding rock of deep tunnels, wherein the wire mesh is a weft plain needle braided structure composed of several steel wires; each steel wire is composed of several U-shaped steel wire coils; the U-shaped steel wire coils of each row of steel wires are sequentially strung together in the same direction to form a wire mesh; irregular springs are provided on each alternate row of steel wires, and the irregular springs are evenly distributed.

[0006] The irregularly shaped spring and the corresponding row of steel wires are an integral structure.

[0007] The irregularly shaped spring is located at the end of the U-shaped steel wire coil in the opposite direction.

[0008] The steel wire is made of low-alloy high-strength steel and is coated with an anti-corrosion coating.

[0009] The opening width of the U-shaped steel wire coil is smaller than the width of the non-open end.

[0010] A U-shaped frame is provided around the wire mesh, with the opening of the U-shaped frame facing outward; an anchor block is provided at the intersection of two U-shaped frames, and the two end faces of the anchor block body are respectively inserted into the horizontally and vertically arranged U-shaped frames. Anchor holes are provided on the anchor block, and anchor rods are inserted into the anchor holes.

[0011] The anchor block has a double-layer structure, and shock-absorbing springs are installed inside the double-layer structure.

[0012] The high impact toughness anchor mesh for deep roadway surrounding rock support in this application adopts the above-mentioned structure and has the following advantages: 1. The wire mesh adopts a weft plain needle weave structure, which can achieve good ductility when stretched in both the horizontal and vertical directions; 2. By using irregularly shaped springs, the traditional passive support is transformed into active pressure relief and energy absorption support, which can more effectively control roadway deformation, suppress roof collapse and sidewall spalling, and provide a higher level of safety protection for underground workers and equipment. 3. Excellent comprehensive mechanical properties: Thanks to the selection of low alloy high strength steel, the outer frame has both high strength and high toughness, which can avoid brittle fracture when subjected to huge static loads and strong dynamic impacts, thus ensuring the reliability of the support. 4. Excellent multi-stage energy absorption and buffering capacity: Combining the macroscopic plastic deformation of the U-shaped frame with the microscopic elastic deformation of the micro springs inside the platform, a highly efficient multi-stage energy absorption mechanism is formed, which can gradually consume the deformation and impact energy of the surrounding rock and significantly reduce the peak load. 5. Excellent adaptability to deformation: This design enables the support system to undergo a certain degree of coordinated deformation with the surrounding rock through the irregular spring energy-absorbing structure of the anchor mesh, thereby better adapting to geological conditions such as soft rock and high ground pressure tunnels that are prone to large deformation. 6. Improved local stress dissipation efficiency: The shock-absorbing springs inside the anchor block can quickly respond to and disperse concentrated stress from the anchor rod, preventing excessive stress concentration at the connection point, protecting the anchor rod and its accessories, and extending the overall service life. 7. Good economy and maintainability: Low alloy high strength steel provides excellent performance while being more cost-effective than higher-end alloy steel, and its modular design makes it easy to replace and maintain locally damaged units in the system. 8. Enhanced active safety protection level: This design transforms traditional passive support into active pressure relief and energy absorption support, which can more effectively control roadway deformation, suppress roof collapse, and provide a higher level of safety protection for underground workers and equipment. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a wire mesh structure.

[0014] Figure 2 This is a schematic diagram of the overall structure of the anchor net in this application.

[0015] Figure 3 This is a schematic diagram of a U-shaped frame structure.

[0016] Figure 4 This is a schematic diagram of the anchor block. Detailed Implementation

[0017] like Figures 1 to 4 As shown, a high impact toughness anchor mesh for deep roadway surrounding rock support is provided. The wire mesh 1 is a weft-needle braided structure composed of several steel wires 2. The wire mesh 1 is made of low alloy high strength steel and is coated with an anti-corrosion coating. It effectively isolates corrosive media such as moisture and acidic water vapor in the roadway, prevents the strength and toughness reduction caused by metal corrosion, avoids the support system from failing prematurely due to hidden corrosion, and ensures that it maintains reliable load-bearing and energy absorption capacity throughout its design life.

[0018] Each steel wire 2 is composed of several U-shaped steel wire coils 3, the opening width of the U-shaped steel wire coil 3 is smaller than the width of the non-open end; the U-shaped steel wire coils 3 of each row of steel wires 2 are strung together in the same direction to form a steel wire mesh; irregular springs 4 are provided on each alternate row of steel wires 2, and the irregular springs 4 are evenly distributed.

[0019] To improve the deformation capacity of the wire mesh 1, the irregular spring 4 is located at the end of the U-shaped wire coil 3 in the opposite direction.

[0020] To ensure the impact resistance and strength of the high-impact toughness anchor mesh, a U-shaped frame 5 is provided around the wire mesh 1, with the opening of the U-shaped frame 5 facing outward. The energy-absorbing outer frame is made of low-alloy high-strength material, which has high strength, good toughness, and excellent welding performance. The U-shaped frame 5 has a unique hollow cavity structure, which has good bending resistance and energy absorption characteristics. When subjected to the deformation pressure of the surrounding rock, the U-shaped frame can undergo controllable elastic or plastic deformation, converting the impact kinetic energy into deformation energy, thereby playing a preliminary buffering and energy dissipation role. Therefore, it has the dual functions of weight reduction and energy absorption.

[0021] An anchor block 6 is installed at the intersection of the two U-shaped frames 5. The two end faces of the anchor block 6 are respectively inserted into the horizontally and vertically arranged U-shaped frames 5. The anchor block 6 is provided with anchor holes 7, and anchor rods are inserted into the anchor holes 7. The anchor block 6 has a double-layer structure, and a shock-absorbing spring 8 is installed inside the double-layer structure. The shock-absorbing spring 8 can efficiently buffer and absorb these high-frequency, low-amplitude disturbances through its compression and rebound, effectively complementing the macroscopic energy absorption of the main outer frame. This design not only further improves the energy absorption efficiency, but also greatly alleviates the fatigue damage of the connection structure, thereby comprehensively enhancing the long-term service capability of the anchor net system under complex geological conditions.

Claims

1. A high-impact toughness anchor mesh for supporting surrounding rock in deep tunnels, characterized in that: The wire mesh (1) is a weft plain needle braided structure composed of several steel wires (2); each steel wire (2) is composed of several U-shaped steel wire coils (3); the U-shaped steel wire coils (3) of each row of steel wires (2) are strung together in the same direction to form a wire mesh; irregular springs (4) are provided on each row of steel wires (2), and the irregular springs (4) are evenly distributed.

2. The high impact toughness anchor mesh for deep tunnel surrounding rock support according to claim 1, characterized in that: The irregular spring (4) and the corresponding steel wire (2) are an integral structure.

3. The high impact toughness anchor mesh for deep tunnel surrounding rock support according to claim 1, characterized in that: The irregular spring (4) is located at the end of the U-shaped wire coil (3) in the opposite direction.

4. The high impact toughness anchor mesh for deep tunnel surrounding rock support according to claim 1, characterized in that: The steel wire (2) is a low-alloy high-strength steel and is coated with an anti-corrosion coating.

5. The high impact toughness anchor mesh for deep tunnel surrounding rock support according to claim 1, characterized in that: The opening width of the U-shaped steel wire coil (3) is smaller than the width of the non-open end.

6. The high impact toughness anchor mesh for deep tunnel surrounding rock support according to claim 1, characterized in that: A U-shaped frame (5) is provided around the wire mesh (1), with the opening of the U-shaped frame (5) facing outward; an anchor block (6) is provided at the intersection of the two U-shaped frames (5), and the two end faces of the main body of the anchor block (6) are respectively inserted into the horizontally and vertically arranged U-shaped frames (5), and an anchor hole (7) is provided on the anchor block (6), and an anchor rod is inserted into the anchor hole (7).

7. The high impact toughness anchor mesh for deep tunnel surrounding rock support according to claim 6, characterized in that: The anchor block (6) has a double-layer structure, and a shock-absorbing spring (8) is provided inside the double-layer structure.

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