A spiked head reinforced anchoring cable and method of use thereof

Abstract

This invention discloses a reinforced anchor cable with barbs and its application method. The cable includes an anchor cable body and a barb device. The anchor cable body is a steel strand, and the barb device consists of a metal wire wound and fixed to the anchor cable body. The two ends of the metal wire are hooked and twisted together to form a braided exposed barb, which forms an angle with the central axis of the anchor cable body. This invention increases the diameter of the anchor cable body, and the barbs easily hook and tear the resin anchoring agent. The invention is simple in structure, safe to use, uses readily available materials, and is inexpensive. On-site installation is fast and effective, with low labor intensity. It can improve the anchoring performance of anchor cables in soft and fractured coal (rock) bodies and solve the technical problem of high anchorage loss rate and difficulty in anchoring in highly rheological coal (rock) bodies.

Description

Technical Field

[0001] This invention relates to anchor cables for support or reinforcement in geotechnical engineering projects such as transportation, water conservancy and hydropower, bridges and tunnels, underground chambers, and urban foundation pits, and in particular to a barbed reinforced anchor cable suitable for mining soft coal (rock) bodies. Background Technology

[0002] Since its introduction in the 1960s, my country has witnessed significant advancements in anchor cable reinforcement technology. In particular, the successful development of small-diameter resin-anchored prestressed anchor cables in 1996 has led to their widespread application in coal mine roadways. This has significantly expanded the scope of anchor mesh support, improved the safety and reliability of roadways, and made them a primary means of reinforcing and strengthening difficult roadways.

[0003] However, during on-site construction and application, existing anchor cables have the following problems: ① Currently, the small-diameter anchor cables used in coal mines are mainly 1×7 structure steel strands with a nominal diameter of φ17.8mm or φ21.6mm. In loose coal (rock) bodies, if wet operation is used, the actual borehole diameter will be larger than the designed borehole diameter due to the vibration of the drill rod and the scouring of the water flow. This results in a mismatch between the borehole diameter, anchor cable diameter, and resin cartridge diameter. In addition, the anchoring agent itself is sometimes deformed by compression. Therefore, during anchoring, the anchor cable may not be properly mixed with the anchoring agent or the anchoring agent may not be fully mixed, which can easily lead to poor anchoring effect or loss of anchorage; ② For loose and broken coal (rock) bodies, the anchoring effect of ordinary anchor cables cannot be guaranteed. If the anchor cable fails to anchor, the upper coal (rock) seam will be unable to form a composite load-bearing structure. This will cause the soft, highly rheological coal (rock) mass to deform significantly under high ground stress, failing to suppress the deformation and damage of the surrounding rock and ensure roof stability, severely impacting construction safety and progress. Therefore, improving the anchoring effect of the anchor cable and increasing its prestress are crucial for maximizing its load-bearing capacity and effectively controlling the deformation of the surrounding rock in the roadway. This also helps avoid secondary expansion and repeated support of newly constructed roadways, thus reducing roadway support costs. Summary of the Invention

[0004] To address the problems caused by mismatched "three diameters" leading to insufficient or uneven mixing of anchoring agent in the borehole anchor cable, unbroken resin cartridges, incomplete extrusion and mixing of anchoring agent, failure to fully fill the borehole area of ​​the inner anchor head, poor adhesion between the anchoring agent and the anchor cable and borehole wall, short effective anchoring length, poor anchoring effect, and unreliable quality, this invention provides a barbed reinforced anchor cable and its application method.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A reinforced anchor cable with barbs includes an anchor cable body and a barb device. The anchor cable body is a steel strand, and the barb device is composed of a metal wire that is wound and fixed on the anchor cable body. The two ends of the metal wire are hooked and twisted into a twisted exposed barb, which forms an angle with the central axis of the anchor cable body.

[0007] One end of the metal wire passes through the inside of the multiple strands of steel wire in the anchor cable body and is fixed to the anchor cable body. The other end is wrapped around the anchor cable body and is wound into multiple turns, with each turn tightly arranged in a row. The exposed barbs of the two ends hooked and twisted together face the anchoring end inside the anchor cable.

[0008] The metal wire is wound 8 to 15 times and has a length of 25 to 50 mm.

[0009] The exposed length of the exposed spike is 5-10 mm.

[0010] The angle between the exposed spike and the central axis of the anchor cable body is 30°.

[0011] The distance from the root of the exposed spike to the inner anchoring end of the anchor cable is 100-200 mm.

[0012] A method for using a barbed reinforced anchor cable, the steps of which are as follows:

[0013] After the anchor cable borehole is formed and before installing the anchor cable, the anchoring agent cartridge is first sent to the bottom of the borehole. Then, the anchor cable body is pushed into the anchor cable borehole. After the anchor cable body slowly pushes the anchoring agent into the bottom of the hole, the anchor cable drilling rig is connected to the anchor cable body, and the anchor cable drilling rig is started. While stirring, the anchor cable body is pushed to the bottom of the hole. During the stirring process, the exposed barbs of the barbed device for reinforcing the anchor cable rotate at high speed, hooking and tearing the anchoring agent cartridge, so that the anchoring agent is stirred more thoroughly and fills the entire borehole area. After the anchoring agent solidifies, the anchor cable tray, gasket and anchor are installed in sequence to carry out the anchor cable pre-tightening work.

[0014] Beneficial effects: The significant technical effects of this invention are reflected in the following aspects:

[0015] 1. The new type of anchor cable with barbed head consists of a standard mining small-diameter resin-anchored prestressed anchor cable and a barbed head device made of 8-13# iron wire. It has a simple structure and is easy to process.

[0016] 2. The fabrication of a new type of barbed anchor cable can be completed using existing equipment. Using pliers, the pre-processed 8-13# iron wire is installed and fixed onto the anchor cable body, forming a... Figure 1 After the spiked device shown, the installation of the new anchor cable can be completed using existing anchor cable drilling rigs and anchoring agents. The anchor cable construction process is simple, with low labor intensity; construction materials are readily available and inexpensive.

[0017] 3. Due to the enlarged borehole diameter caused by the wet drilling and hydraulic perforation process, ordinary anchor cables often fail to break the tack cartridge, resulting in insufficient mixing of the anchoring agent and compromised anchoring effectiveness. This new type of anchor cable spike device, with its hook point rotating at high speed under the drive of the anchor cable drilling rig, acts like a sharp knife, easily breaking the tack cartridge and allowing the anchoring agent to be squeezed out smoothly, mixed evenly, and achieving a thorough anchoring effect.

[0018] 4. Compared with ordinary anchor cables, this new type of anchor cable with barbed reinforcement can more evenly mix the anchoring agent, making the anchoring agent more densely fill the borehole area and improving the bonding stress between the anchor body and the surrounding rock. Especially for soft and broken coal (rock) bodies, the improvement is greater, which can give full play to the anchoring effect of the anchor cable body and reduce the cost of roadway support. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the barbed reinforced anchor cable of the present invention;

[0020] Figure 2 yes Figure 1 AA-direction cross-section diagram;

[0021] Figure 3 This is a schematic diagram of the installation of the barbed reinforced anchor cable of the present invention;

[0022] In the figure: 1-Anchor cable body, 2-Barb device, 201-Exposed barb, 3-Drill hole, 4-Anchoring agent, 5-Anchor, 6-Gasket, 7-Anchor cable tray. Detailed Implementation

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] like Figure 1The diagram shows a reinforced anchor cable with barbs according to the present invention, comprising an anchor cable body 1 and a barb device 2. The anchor cable body 1 is a 1×7 steel strand. The barb device 2 is composed of a single iron wire. One end of the iron wire passes through an outer strand of the steel strand in the anchor cable body 1 and is clamped between the outer strand and the core wire of the steel strand, and is fixed to the anchor cable body 1. The other end is wound around the anchor cable body 1 and wound into 8 to 15 turns, each turn being tightly arranged in a row, with L2 generally being 25 to 50 mm. The two ends are hooked together and twisted into a spiral-shaped exposed barb 201 facing the inner anchoring end of the anchor cable. The exposed length of the exposed barb 201 is 5 to 10 mm, and the angle between the exposed barb 201 and the central axis of the anchor cable body 1 is 30°. The distance L1 from the root of the exposed barb 201 to the inner anchoring end of the anchor cable is approximately 100 to 200 mm. In this invention, the anchor cable body 1 adopts a steel strand cable body with a standard small-diameter resin anchoring prestressed anchor cable 1×7 structure for mining, with a nominal diameter D1 of φ17.8mm or φ21.6mm; the diameter of the iron wire is D3, and the total diameter of the cable body D2, including the area where the iron wire is wrapped, is approximately φ24~28mm.

[0025] This invention employs an 8-13# iron wire barbed device, one end of which passes through a strand of steel wire on the anchor cable body and is tightly squeezed between the steel strand and the core wire. This design prevents the anchor cable from slipping along the cable body towards the outer end during installation due to slippage between the barbed device and the anchor cable body, thus strengthening the anchoring effect and improving the anchoring performance. This increases the diameter of the anchor cable body, and the barbed device easily hooks and tears the resin anchoring agent. In soft and fractured coal (rock) bodies, anchor cable drilling results are unsatisfactory, especially in rheological coal (rock) bodies. When using wet drilling, the water flow can cause the actual borehole diameter to be larger than the designed diameter, resulting in insufficient mixing of the resin anchoring agent during anchor cable installation or reduced anchoring performance. This patent was developed to address this technical challenge. This invention has a simple structure, is safe to use, uses readily available materials, and is inexpensive. On-site installation is fast and effective, with low labor intensity. This technology can improve the anchoring performance of anchor cables in soft and fractured coal (rock) masses, and solve the technical problem of high anchoring failure rate and difficulty in anchoring in highly rheological coal (rock) masses. It creates conditions for smooth anchoring during installation in rheological coal (rock) masses, and ensures that the anchoring agent is evenly mixed and completely fills the anchoring area at the bottom of the borehole. It provides timely and active support for the anchor cables, and increases the anchoring force in rheological coal (rock) masses, preventing anchor cable failure. This reduces roadway support costs, maximizes the support performance of anchor cable support materials, and provides better technical support for effectively controlling the deformation of rheological coal (rock) masses.

[0026] like Figure 3 As shown, the method of using this invention is as follows:

[0027] After the anchor hole 3 is formed and before installing the anchor cable, the anchoring agent cartridge is first sent to the bottom of the borehole. Then, the anchor cable body 1 is pushed into the anchor hole 3. After the anchor cable slowly pushes the anchoring agent 3 into the bottom of the hole, the anchor cable drilling machine is connected to the anchor cable body 1, and the drilling machine is started. While stirring, the anchor cable body 1 is pushed to the bottom of the hole. During the stirring process, the outer barb 201 of the barb device 2 on the anchor cable body 1 rotates at high speed, like a sharp knife, which easily hooks and cuts the anchoring agent cartridge, thereby making the resin anchoring agent 4 more fully stirred and filling the entire borehole area. At the same time, the iron wire wrapped on the anchor cable body 1 also increases the diameter of the anchor cable body. This locally enlarged diameter anchor cable enhances the anchoring effect and provides stronger anchoring force. After the anchoring agent solidifies, the anchor cable tray 7, gasket 6, and anchor 5 are installed in sequence to perform anchor cable pre-tightening work to achieve the designed pre-tightening force.

[0028] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A barbed reinforced anchor cable, characterized in that: It includes an anchor cable body (1) and a spike device (2). The anchor cable body (1) is a steel strand, and the spike device (2) is composed of a metal wire, which is wound and fixed on the anchor cable body (1). The two ends of the metal wire are hooked and twisted into a twisted exposed spike (201). The twisted exposed spike (201) forms an angle with the central axis of the anchor cable body (1). One end of the metal wire passes through the inside of the multiple strands of steel strands in the anchor cable body (1), is sandwiched between the steel strands on the outer ring of the anchor cable body (1) and the core wire of the steel strands, and is fixed on the anchor cable body (1). The other end is wrapped around the anchor cable body (1) and is wound into multiple turns, each turn is tightly arranged in a row, and the exposed barb (201) of the two ends hooked and twisted together faces the anchoring end inside the anchor cable. The angle between the exposed spike (201) and the central axis of the anchor cable body (1) is 30°.

2. The reinforced anchor cable with barbed head according to claim 1, characterized in that: The metal wire is wound 8 to 15 times and has a length of 25 to 50 mm.

3. The barbed reinforced anchor cable according to claim 1, characterized in that: The exposed length of the exposed spike (201) is 5-10 mm.

4. The barbed reinforced anchor cable according to claim 1, characterized in that: The distance from the root of the exposed spike (201) to the inner anchoring end of the anchor cable is 100-200 mm.

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