Expansion threaded anchor rod device for reinforcing dangerous rock mass and mounting method

Abstract

The invention relates to the technical field of civil engineering, in particular to an expansion threaded anchor rod device for reinforcing a dangerous rock body and an installation method. During use, an inner screw-in rod is pre-connected with a hollow outer anchor pipe through threaded connection to form an anchor rod assembly. And the anchor rod assembly is screwed into a bedrock drill hole to the designed depth according to a preset torque value, and the inner screw-in rod is separated through reverse rotation and completely drawn out. The expansion type chemical anchoring agent is put into a pipe cavity through a glue injection channel of the hollow outer anchor pipe, the inner screw-in rod is screwed into the hollow outer anchor pipe for the second time, and when the torque value reaches a threshold value, an extrusion head at the tail end of the screw-in rod breaks a brittle protective shell of the chemical anchoring agent. The chemical anchoring agents are mixed to generate expansion pressure, the wedge-shaped petal pieces of the expansion head are driven to be expanded in the radial direction and embedded into bed rock to form mechanical anchoring, exosmosis chemical slurry enters rock mass fractures and forms a reinforcing area with the diameter of 300-500 mm after being cured, and therefore the problem that a traditional anchor rod is prone to falling off and difficult to achieve long-term stable reinforcing is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering, and in particular to an expansion thread anchor device for reinforcing dangerous rock masses and an installation method thereof. Background Art

[0002] Anchor support technology originated in the early 20th century and was initially used primarily for mine tunnel support. With the development of technology and the diversification of engineering needs, its application has gradually expanded to geotechnical engineering fields such as tunnels, slopes, and foundation pits. Traditional support methods such as wooden supports, steel arches, or concrete linings rely primarily on passively bearing the pressure of the surrounding rock. This method not only consumes a large amount of material but also has obvious limitations in adaptability. With the continuous advancement of geotechnical mechanics theory, people have gradually realized that actively reinforcing the surrounding rock through the bonding and friction between anchors and rock and soil can effectively improve the self-stabilization capacity of the surrounding rock, making it a more efficient and economical support method.

[0003] Commonly used rock reinforcement anchors include ordinary steel anchors, resin anchors, and hollow grouting anchors. However, these traditional anchors have numerous drawbacks in practical applications: ordinary steel anchors lack sufficient flexibility and adaptability to effectively handle large rock deformations and are prone to falling off, potentially causing secondary damage to the rock; resin anchors are relatively expensive, and their performance is extremely unstable in complex environments with large temperature and humidity fluctuations, making it difficult to ensure long-term, reliable support; and the steel tube wall of hollow grouting anchors is susceptible to corrosion, reducing their durability and making it difficult to meet the requirements of long-term rock support. Summary of the Invention

[0004] The purpose of the present invention is to provide an expansion threaded anchor device and an installation method for reinforcing dangerous rock masses, aiming to solve the problem that traditional anchors are easy to fall off and difficult to achieve long-term stable reinforcement.

[0005] To achieve the above-mentioned objectives, in the first aspect, the present invention provides an expansion threaded anchor device for reinforcing dangerous rock bodies, comprising an inner threading rod, a hollow outer anchor tube and an expansion type chemical anchoring agent, wherein the outer surface of the inner threading rod is threaded, the inner and outer surfaces of the hollow outer anchor tube are threaded, the tail has an opening, and the head has an expansion head, the expansion type chemical anchoring agent is wrapped in a brittle shell and is located in the expansion head, the outer diameter of the inner threading rod is smaller than the inner diameter of the hollow outer anchor tube, and can be threadedly connected.

[0006] Wherein, the hollow outer anchor pipe and the expansion head are an integrated structure.

[0007] Wherein, the expansion head has a slot.

[0008] Wherein, the tail of the inward-screwing rod is provided with an anti-horizontal washer and a hexagonal nut.

[0009] In a second aspect, a method for installing an expansion threaded anchor for reinforcing a dangerous rock mass is provided, which is used in the expansion threaded anchor device for reinforcing a dangerous rock mass described in the first aspect, comprising the following steps:

[0010] The internal screw rod is pre-assembled into an anchor rod assembly by threading it with the hollow external anchor pipe. With the help of a rotary propulsion device, it is screwed into the bedrock borehole to the designed depth according to the predetermined torque, leaving a gap of 3-5mm between the expansion head at the end of the hollow external anchor pipe and the bottom of the hole;

[0011] After the anchor rod assembly is fixed, rotate it in the opposite direction to separate it and pull out the inner screw rod to form a glue injection channel. Inject the expansion type chemical anchoring agent into the hollow outer anchor tube to the position of the expansion head to keep the protective shell intact;

[0012] When the torque reaches a certain value during the secondary screwing of the inward screw rod, the extrusion head at the end of the inward screw rod breaks the outer shell of the chemical anchoring agent. The chemical anchoring agent mixes and generates expansion pressure, which pushes the wedge-shaped petals of the expansion head to expand radially to form a mechanical anchor. At the same time, the chemical anchoring agent seeps into the rock cracks and solidifies, forming a reinforcement area with a diameter of 300-500mm.

[0013] Add an anti-leveling washer to the tail of the inward-screwing rod and tighten the hexagonal nut to isolate it from the external environment.

[0014] The present invention provides an expansion threaded anchor device for reinforcing dangerous rock masses. When in use, the inner threaded rod is pre-connected with the hollow outer anchor tube through a threaded connection to form an anchor assembly. A rotary propulsion device is used to screw the anchor assembly into the bedrock borehole to the designed depth according to a predetermined torque value, ensuring that a gap of 3-5mm is maintained between the expansion head at the end of the hollow outer anchor tube and the bottom of the hole. After the anchor assembly is fixed, reverse rotation is performed to separate the inner threaded rod and completely pull it out. An expansion-type chemical anchoring agent is placed into the lumen through the glue injection channel of the hollow outer anchor tube, and it is ensured that the agent reaches the position of the expansion head and the protective shell is not damaged. The inner threaded rod is screwed into the hollow outer anchor tube for a second time. When the torque value reaches a certain value, the extrusion head at the end of the threaded rod will break the brittle protective shell of the chemical anchoring agent. At this point, the chemical anchoring agent generates expansion pressure after mixing, driving the wedge-shaped petals of the expansion head to expand radially and embed into the bedrock to form a mechanical anchor. The chemical slurry seeps into the rock cracks and solidifies to form a reinforcement zone with a diameter of 300-500mm. An anti-leveling washer is added to the tail of the internal threaded rod and the hexagonal nut is tightened to isolate the external environment and further strengthen the anchoring capacity of the anchor rod. This solves the problem of traditional anchor rods easily falling off and making it difficult to achieve long-term stable reinforcement. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0016] Figure 1 The present invention provides a structural schematic diagram of an expansion threaded anchor device for reinforcing dangerous rock masses.

[0017] Figure 2 It is a schematic diagram of the hollow outer anchor pipe structure of the present invention.

[0018] Figure 3 This is a schematic diagram of the inward-rotating rod structure of the present invention;

[0019] Figure 4 It is a schematic diagram of the top structure of the present invention.

[0020] Figure 5 Schematic diagram of the installation steps of the present invention.

[0021] Figure 6 It is a schematic structural diagram of the expansion head of the present invention.

[0022] Figure 7 yes Figure 1 sectional view of .

[0023] Figure 8 The present invention provides a flow chart of a method for installing an expansion threaded anchor rod for reinforcing a dangerous rock mass.

[0024] In the figure: 1-hollow outer anchor pipe, 2-inner screw rod, 3-expandable chemical anchor, 11-expansion head, 21-anti-leveling gasket, 22-hexagonal nut, 23-opening, 24-slot. DETAILED DESCRIPTION

[0025] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0026] See also Figures 1 to 7In the first aspect, the present invention provides an expansion threaded anchor device for reinforcing dangerous rock masses, comprising an inner threading rod 2, a hollow outer anchor tube 1 and an expansion type chemical anchoring agent 3, wherein the outer surface of the inner threading rod 2 is threaded, the inner and outer surfaces of the hollow outer anchor tube 1 are threaded, and the tail has an opening 23, and the head has an expansion head 11, the expansion type chemical anchoring agent 3 is wrapped in a brittle shell and is located in the expansion head 11, the outer diameter of the inner threading rod 2 is smaller than the inner diameter of the hollow outer anchor tube 1, and can be threadedly connected.

[0027] Furthermore, the hollow outer anchor pipe 1 and the expansion head 11 are an integrated structure.

[0028] Furthermore, the expansion head 11 has a slot 24 .

[0029] Furthermore, an anti-horizontal washer 21 and a hexagonal nut 22 are provided at the tail of the inwardly threaded rod 2 .

[0030] In this embodiment, when in use, the inner screw-in rod 2 is pre-connected with the hollow outer anchor tube 1 through a threaded connection to form an anchor rod assembly. Use a rotary propulsion device to screw the anchor rod assembly into the bedrock borehole to the designed depth according to a predetermined torque value, ensuring that the expansion head 11 at the end of the hollow outer anchor tube 1 maintains a gap of 3-5mm with the bottom of the hole. After the anchor rod assembly is fixed, reverse the rotation to separate the inner screw-in rod 2 and pull it out completely. Put the expandable chemical anchor 3 into the tube cavity through the glue injection channel of the hollow outer anchor tube 1, and ensure that the agent reaches the position of the expansion head 11 and the protective shell is not damaged. Screw the inner screw-in rod 2 into the hollow outer anchor tube 1 for the second time. When the torque value reaches a certain value, the extrusion head at the end of the screw-in rod will break the brittle protective shell of the chemical anchor. At this point, the chemical anchoring agent generates expansion pressure, driving the wedge-shaped petals of the expansion head 11 to expand radially, embedding into the bedrock to form a mechanical anchor. The chemical slurry seeps into the rock fissures and solidifies to form a reinforced area with a diameter of 300-500mm. Adding an anti-leveling washer 21 to the tail of the internal threaded rod 2 and tightening the hexagonal nut 22 isolates it from the external environment and further strengthens the anchoring capacity of the anchor rod. This solves the problem of traditional anchor rods easily falling off and making it difficult to achieve long-term stable reinforcement.

[0031] See also Figure 8 In a second aspect, a method for installing an expansion threaded anchor for reinforcing a dangerous rock mass is provided, which is used in the expansion threaded anchor device for reinforcing a dangerous rock mass described in the first aspect, comprising the following steps:

[0032] S1: Pre-assemble the internal screw rod 2 and the hollow external anchor pipe 1 into an anchor rod assembly by threading. Then, screw it into the bedrock borehole to the designed depth with the help of a rotary propulsion device according to a predetermined torque, leaving a gap of 3-5mm between the expansion head 11 at the end of the hollow external anchor pipe 1 and the bottom of the hole.

[0033] Specifically, the inner screw rod 2 is screwed together with the hollow outer anchor pipe 1 through threads to form a composite anchor rod assembly, and the assembly is screwed into the prefabricated rock mass borehole to the designed depth by a rotary propulsion method to complete temporary anchoring.

[0034] After the S2 anchor assembly is fixed, reverse the rotation to separate and extract the inner screw rod 2 to form a glue injection channel, and inject the expandable chemical anchoring agent 3 into the hollow outer anchor tube 1 to the position of the expansion head 11, keeping the protective shell intact;

[0035] Specifically, after the anchor system is initially fixed, the rod 2 is rotated in the reverse direction to exit the inner rotation to form a glue injection channel; the expandable chemical anchor glue is inserted through the hollow channel of the hollow outer anchor tube 1 to ensure that the glue is completely placed to the expansion head 11.

[0036] S3 is screwed into the inner screw rod 2 for the second time. When the torque reaches a certain value, the extrusion head at the end of the inner screw rod 2 breaks the shell of the chemical anchoring agent. The chemical anchoring agent mixes and generates expansion pressure, which pushes the wedge-shaped petals of the expansion head 11 to expand radially to form a mechanical anchor. At the same time, the exudate chemical anchoring agent enters the rock cracks and solidifies, forming a reinforcement area with a diameter of 300-500mm.

[0037] Specifically, the second screw-in screw rod 2 is screwed in for torque loading, and the brittle protective shell of the chemical anchor is broken by the shear device at the end of the screw; the expansion head 11 is driven to expand radially under the action of pressure to form a mechanical wedge anchor; the released chemical anchor adhesive reacts in the pores of the rock mass, producing a volume expansion effect, forming a chemical-mechanical composite anchoring system.

[0038] S4 adds an anti-horizontal washer 21 to the tail of the inwardly screwed rod 2 and tightens the hexagonal nut 22 to isolate it from the external environment.

[0039] Specifically, a standard anchor assembly (anti-horizontal gasket 21 and hexagonal nut 22) is installed at the tail of the internal threaded rod 2, and the designed torque value is applied to perform end sealing treatment. The internal cavity of the anchor rod is closed through the axial compression action of the threaded pair, blocking interference from external environmental factors, maintaining a closed reaction environment for the chemical anchor adhesive, and ensuring the continuous development of the expansion effect and the long-term durability of the anchoring system.

[0040] Beneficial effects:

[0041] 1. The device and installation method of the present invention make anchor construction flexible, convenient and fast, without requiring a large amount of support materials or reinforced formwork and other engineering conditions required for traditional support, which can effectively reduce the cost of support projects and shorten the construction period.

[0042] 2. Through the synergistic effect of mechanical expansion and chemical expansion, a dual anchoring effect is achieved, which effectively improves the load transfer performance and long-term stability of the anchoring system. The expansion pressure can better couple with the hole wall, making the expansion head more firmly anchored into the surrounding rock, thereby improving the overall stability and anchoring capacity of the anchor rod.

[0043] 3. The chemical anchoring agent on the head and the waterproof locking piece on the end isolate the internal environment of the anchor rod from the external environment, which enhances the durability of the anchor rod and effectively avoids the corrosion of the internal environment of the anchor rod due to external conditions.

[0044] 4. The space required for anchor support construction is relatively small, and it can be applied to more complex geological environments that are not suitable for large-scale construction.

[0045] 5. The later maintenance cost is low, and the overall safety and economic benefits are more prominent. The coordinated load-bearing of mechanical anchoring and chemical bonding anchoring further improves the anchoring capacity of the anchor rod and reduces the risk of rock collapse during construction.

[0046] 6. The infiltrated chemical slurry and the rock cuttings in the borehole produce an interfacial penetration effect. The broken rock mass and the broken brittle shell fragments are used as aggregates to form a composite reinforcement area during the curing process of the chemical anchoring agent, thereby improving the reinforcement effect.

[0047] The above disclosure is only a preferred embodiment of the expansion threaded anchor device and installation method for reinforcing dangerous rock masses of the present invention. Of course, this cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. An expansion thread anchor device for reinforcing dangerous rock mass, characterized in that: It includes an inner screw-in rod, a hollow outer anchor tube and an expandable chemical anchoring agent. The outer surface of the inner screw-in rod is threaded, the inner and outer surfaces of the hollow outer anchor tube are threaded, the tail has an opening, and the head has an expansion head. The expandable chemical anchoring agent is wrapped in a brittle shell and is located in the expansion head. The outer diameter of the inner screw-in rod is smaller than the inner diameter of the hollow outer anchor tube and can be threadedly connected.

2. The expansion thread anchor device for reinforcing dangerous rock mass according to claim 1, characterized in that: The hollow outer anchor pipe and the expansion head are an integrated structure.

3. The expansion thread anchor device for reinforcing dangerous rock mass according to claim 1, characterized in that: The expansion head has a slot.

4. The expansion thread anchor device for reinforcing dangerous rock mass according to claim 1, characterized in that: The tail of the inwardly threaded rod is provided with an anti-horizontal washer and a hexagonal nut.

5. A method for installing an expansion threaded anchor for reinforcing a dangerous rock mass, used for the expansion threaded anchor device for reinforcing a dangerous rock mass according to any one of claims 1 to 4, characterized in that: The following steps are involved: The internal screw rod is pre-assembled into an anchor rod assembly by threading it with the hollow external anchor pipe. With the help of a rotary propulsion device, it is screwed into the bedrock borehole to the designed depth according to the predetermined torque, leaving a gap of 3-5mm between the expansion head at the end of the hollow external anchor pipe and the bottom of the hole; After the anchor rod assembly is fixed, rotate it in the opposite direction to separate it and pull out the inner screw rod to form a glue injection channel. Inject the expansion type chemical anchoring agent into the hollow outer anchor tube to the position of the expansion head to keep the protective shell intact; When the torque reaches a certain value during the secondary screwing of the inward screw rod, the extrusion head at the end of the inward screw rod breaks the outer shell of the chemical anchoring agent. The chemical anchoring agent mixes and generates expansion pressure, which pushes the wedge-shaped petals of the expansion head to expand radially to form a mechanical anchor. At the same time, the chemical anchoring agent seeps into the rock cracks and solidifies, forming a reinforcement area with a diameter of 300-500mm. Add an anti-leveling washer to the tail of the inward-screwing rod and tighten the hexagonal nut to isolate it from the external environment.

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