Self-adaptive multi-point anchoring pre-stressed anchor rod and method

Abstract

The invention discloses a self-adaptive multi-point anchoring pre-stressed anchor rod and method, and relates to the technical field of tunnel construction, the self-adaptive multi-point anchoring pre-stressed anchor rod comprises a fixed check ring arranged in a drill hole and an anchor rod base plate arranged below the drill hole, a rapid anchoring type cartridge is arranged at the top of the drill hole, a hollow slow anchoring type cartridge is arranged on the fixed check ring, and the hollow slow anchoring type cartridge is arranged on the anchor rod base plate. A fixing nut is arranged below the anchor rod base plate, an anchor rod body sequentially penetrates through the fixing nut, the anchor rod base plate, the fixing check ring and the hollow slow anchoring type cartridge to extend into the drill hole, and the combination position of an anchoring agent and the anchor rod body is determined according to the distribution condition of surrounding rock within the anchor rod supporting range; and then asynchronous anchoring is achieved by adopting binding materials with different anchoring speeds according to the combination position, finally anchor rod fixing is conducted in the effective process of the anchoring agent, the bearing capacity of a supporting structure is improved by applying prestress, and stability and safety of a tunnel structure in the construction process are guaranteed.

Description

[0001] Methodology Area

[0002] The invention relates to the technical field of tunnel construction, and in particular to an adaptive multi-point anchoring prestressed anchor rod and a method thereof.

[0003] Background Methods

[0004] With the continuous construction and development of my country's transportation infrastructure, tunnel projects are gradually developing in the direction of being deeper, larger and longer, and the geological conditions they face are more complex. In order to ensure the safe construction of tunnel projects and the stability of surrounding rocks, reasonable construction methods and support structures are particularly important. In the process of tunnel excavation, in order to give full play to the bearing capacity of the surrounding rocks themselves, anchor support technology represented by anchor rods has been widely used. This technology mainly embeds anchors into the surrounding rocks by drilling, and combines anchoring agents to form an integral whole with the surrounding rocks, thereby enhancing the strength and stability of the surrounding rocks. However, in the current construction method, the anchoring section is mainly concentrated at the top of the anchor rod, and most of the remaining rod body is a free section, which is easy to cause uneven stress distribution of the rod body and stress concentration. In addition, the surrounding rock distribution is relatively complex, and the deformation of the surrounding rock at different depths is different, which further leads to uneven force and reduces the combination effect of the anchor rod and the surrounding rock. Therefore, a support method is needed to improve the force distribution of the rod body and the surrounding rock reinforcement effect, and improve the stability and applicability of the support structure;

[0005] In the prior art, for example, CN219472136U discloses a tunnel anchor for highway tunnel design, including a grouting pipe, a mounting box, a sliding block, a fixing assembly, a rack, and a gear. The grouting pipe is used to inject slurry into the mounting hole, and the slurry outlet hole is used to flow the slurry in the grouting pipe into the mounting hole. The mounting box provides an installation position for the fixing assembly, and the fixing assembly is used to fix the tunnel anchor. The limit assembly is used to limit the reverse rotation of the gear. When the sliding block moves to the side close to the grouting pipe, it drives the rack to move, causing the gear to rotate, and further drives the first fixing rod to rotate. When one end of the first fixing rod contacts the side wall of the borehole, it can form a support for the anchor rod body. In the subsequent construction process, the anchor rod is prevented from moving, thereby fixing the tunnel anchor rod, and forming support for the tunnel anchor rod before injecting slurry, reducing the shaking of the tunnel anchor rod when injecting slurry, and enhancing the stability of the tunnel anchor rod installed in the tunnel mounting hole.

[0006] However, in actual projects, the geological conditions of the tunnel surrounding rock are very complex. The single-point anchoring method currently used mainly regards the surrounding rock as a homogeneous rock mass for anchor rod structure design, without considering the changes in the geological conditions of the surrounding rock along the depth direction. There are differences in the deformation of different types of surrounding rock, which can easily lead to uneven force on the rod body. In addition, the structural design of the anchor rod body is relatively complex and difficult to adapt to the deformation of different types of surrounding rock. Therefore, how to consider the changes in the surrounding rock when designing the anchor support method is of great significance to the support effect.

[0007] Therefore, an adaptive multi-point anchoring prestressed anchor rod and method are provided to solve the above problems. Summary of the invention

[0008] The purpose of the present invention is to provide an adaptive multi-point anchoring prestressed anchor rod and method. During the tunnel excavation process, the anchor rod is embedded in the surrounding rock and combined with an anchoring agent to form an integral structure of the two to improve the bearing capacity and stability of the surrounding rock, thereby achieving the purpose of tunnel support. At the same time, the anchor rod force distribution and surrounding rock reinforcement effect are improved, so that the anchor rod can better adapt to the deformation of the surrounding rock.

[0009] To achieve the above-mentioned objectives, the present invention provides an adaptive multi-point anchoring prestressed anchor rod, comprising a fixed retaining ring arranged in a borehole and an anchor rod pad arranged below the borehole, a quick anchoring type drug coil is arranged at the top of the borehole, a hollow slow anchoring type drug coil is arranged on the fixed retaining ring, a fixing nut is arranged below the anchor rod pad, and the anchor rod body passes through the fixing nut, the anchor rod pad, the fixed retaining ring and the hollow slow anchoring type drug coil in sequence and extends to the interior of the borehole.

[0010] Preferably, the number of the fixed retaining ring and the hollow slow anchoring type medicine roll is not fixed, and the fixed retaining ring is a hollow rigid gasket.

[0011] Preferably, the hollow slow-anchoring medicine roll comprises a stirring device and a slow-anchoring medicine roll wrapped around the outside of the stirring device, the stirring device is a single-layer adhesive film, and the stirring device is fixedly connected to the anchor rod body by gluing.

[0012] Preferably, a plurality of stirring blades are symmetrically arranged on the outer walls of both sides of the stirring device, and the stirring blades are movably connected to the stirring device by means of a spherical hinge.

[0013] Preferably, the anchor rod body and the fixing retaining ring are fixedly connected by gluing, and the anchor rod body and the fixing nut are fixedly connected by a threaded structure.

[0014] A method for implementing an adaptive multi-point anchoring prestressed anchor rod comprises the following steps: S1: According to the engineering geological survey report and combined with the geological detection technology of the construction site, determine the boundary position of different types of surrounding rocks; S2: Place the quick anchoring coil in the drill hole, and install the hollow slow anchoring coil and fixed retaining ring at the corresponding position of the rod; S3: Use an anchor drilling rig to push the anchor rod body and the drug coil into the borehole until they come into contact with the deep surrounding rock, rotate the anchor rod body and stir the drug coil to make it contact with the anchor rod and the surrounding rock and react; S4: After the initial anchoring of the top of the anchor is completed, the anchor is tensioned at the free end using an anchor drill, and the anchor pad and fixing nut are installed to complete the prestressed locking and anchor installation.

[0015] Preferably, in step S2, a hollow slow anchoring type medicine coil and a fixed retaining ring are installed at corresponding positions of the rod body, which specifically includes the following steps: S21: Install the fixed retaining ring at the corresponding position of the anchor rod body; S22: Paste the stirring device around the rod body and onto the fixed retaining ring; S23: Wrap the slowly anchoring medicine around the rod body and wrap it around the outside of the stirring device.

[0016] Therefore, the present invention adopts an adaptive multi-point anchoring prestressed anchor rod and method of the above structure, which has the following beneficial effects: (1) This scheme takes into account the changes in the surrounding rock within the support range and adopts a distributed anchoring method, which can improve the force distribution of the anchor rod and the surrounding rock reinforcement effect, making the force distribution of the rod more uniform and better adapting to the deformation of the surrounding rock; (2) The operation process of this scheme is simple, convenient and fast. It does not require additional complicated construction steps and does not generate additional construction waste. It is economical, convenient, safe and environmentally friendly. (3) The hollow slow anchoring drug coils distributed on the anchor rod body of this scheme can ensure the stability of the anchor rod body in the borehole, that is, the axis of the rod body remains parallel to the axis of the borehole without deviation, which can improve construction efficiency and ensure excellent construction quality; (4) This scheme can adapt to different types of surrounding rock geological conditions and can be used as an auxiliary method to enhance the support effect of different types of anchor bolts, with wider applicability.

[0017] The method scheme of the present invention is further described in detail below through the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of an adaptive multi-point anchoring prestressed anchor rod of the present invention; Figure 2 This is a structural diagram of the hollow slow anchoring medicine roll of the present invention; Figure 3 is a structural diagram of the stirring device of the present invention; Figure 4 The present invention is a flow chart of an implementation method of an adaptive multi-point anchoring prestressed anchor rod.

[0019] Among them: 1. Tunnel surrounding rock; 2. Quick anchoring cartridge; 3. Drilling; 4. Hollow slow anchoring cartridge; 5. Anchor rod body; 6. Fixed retaining ring; 7. Anchor pad; 8. Fixed nut; 9. Slow anchoring cartridge; 10. Stirring device; 11. Stirring blade. DETAILED DESCRIPTION

[0020] The method scheme of the present invention is further described below through drawings and embodiments.

[0021] Unless otherwise defined, method terms or scientific terms used in the present invention shall have the common meanings understood by one of ordinary skill in the art to which the present invention belongs.

[0022] The words "include" or "comprises" and the like used in the present invention mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of also including other elements. The orientation or position relationship indicated by the terms "inside", "outside", "upper", "lower", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention. When the absolute position of the described object changes, the relative position relationship may also change accordingly. In the present invention, unless otherwise clearly specified and limited, the terms "attachment" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between 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.

[0023] Example like Figure 1 As shown, the present invention provides an adaptive multi-point anchoring prestressed anchor rod, comprising a fixed retaining ring 6 arranged in a borehole 3 and an anchor rod pad 7 arranged below the borehole 3, a quick anchoring type drug roll 2 is arranged at the top of the borehole 3, and the quick anchoring type drug roll 2 uses an anchoring agent with a fast anchoring speed, which is mainly stirred by rotating the top of the anchor rod body 5, and can be quickly bonded to form an integral structure between the anchor rod body 5 and the surrounding rock; A hollow slow anchoring type medicine roll 4 is arranged on the fixed retaining ring 6, and a fixing nut 8 is arranged under the anchor pad 7. The anchor rod body 5 passes through the fixing nut 8, the anchor pad 7, the fixed retaining ring 6 and the hollow slow anchoring type medicine roll 4 in sequence and extends to the inside of the borehole 3. The anchor rod body 5 and the fixed retaining ring 6 are fixedly connected by gluing, and the anchor rod body 5 and the fixing nut 8 are fixedly connected by a threaded structure. The number of fixed retaining rings 6 and hollow slow anchoring type medicine rolls 4 are not fixed, and the fixed retaining ring 6 is a hollow rigid gasket.

[0024] like Figure 2 As shown, the hollow slow anchoring medicine roll 4 includes a stirring device 10 and a slow anchoring medicine roll 9 wrapped around the outside of the stirring device 10. The slow anchoring medicine roll 9 uses an anchoring agent with a relatively slow anchoring speed. There is no connection between the slow anchoring medicine roll 9 and the anchor rod body 5. The stirring device 10 is a single-layer adhesive film, and the stirring device 10 and the anchor rod body 5 are fixedly connected by gluing.

[0025] like Figure 3 As shown, a plurality of stirring blades 11 are symmetrically arranged on the outer walls of both sides of the stirring device 10, and the stirring blades 11 are movably connected to the stirring device 10 by means of a spherical hinge; The slow anchoring medicine roll 9 mainly relies on the centrifugal force generated during the rotation of the anchor rod body 5 to rotate the stirring blades 11 installed around the stirring device 10, thereby achieving medicine roll stirring.

[0026] This distributed anchoring method can increase the number of free sections and anchoring sections of the anchor rod body 5, making the force distribution of the anchor rod body 5 more uniform, and the anchoring method that is adaptive to the surrounding rock type can achieve a more complete combination of the anchor rod body 5 and the surrounding rock, better adapt to the deformation of the surrounding rock, and thus improve the anchor force distribution and surrounding rock reinforcement effect, and improve the applicability and reliability of the support structure. In addition, in the process of sufficient stirring of the drug roll for bonding and anchoring, due to the different anchoring speeds, the top of the anchor rod body 5 first has a certain strength. During the anchoring process of the hollow slow anchoring drug roll 4, an anchor drill can be used to tension the anchor at the free end, and at the same time, the anchor pad 7 and the fixing nut 8 are installed for prestressed locking and anchor fixing. This asynchronous anchoring method can apply prestress to the anchor rod, further improve the bearing capacity and stability of the support structure, and ensure the stability and safety of the tunnel structure.

[0027] like Figure 4 As shown, a method for implementing an adaptive multi-point anchoring prestressed anchor rod comprises the following steps: S1: According to the anchor installation position predetermined in the construction plan, combined with the geological detection technology of the construction site, the anchor drilling rig is used to drill holes. During the drilling process, the construction personnel pay attention to the changes in the rock slag, determine the boundary positions of different types of surrounding rocks, obtain the engineering geological survey report, and combine the engineering geological survey report with the changes in the surrounding rock types revealed during the drilling construction process to determine the anchor rod position corresponding to the boundary positions of different types of surrounding rocks; S2: The quick anchoring drug coil is placed in the borehole, and the anchor drill pushes the anchor rod body to continuously go deeper into the borehole, thereby pushing the quick anchoring drug coil to continuously go deeper until it contacts the deep surrounding rock, and a hollow slow anchoring drug coil and a fixed retaining ring are installed at the corresponding position of the rod body; In step S2, a hollow slow anchoring type medicine coil and a fixed retaining ring are installed at corresponding positions of the rod body, which specifically includes the following steps: S21: Install the fixed retaining ring at the corresponding position of the anchor rod body; S22: Paste the stirring device around the rod body and onto the fixed retaining ring; S23: Wrap the slowly anchoring medicine around the rod body for one circle on the outside of the stirring device; S3: Use an anchor drill to push the anchor rod body and the drug coil into the borehole until they come into contact with the deep surrounding rock, rotate the anchor rod body to stir the drug coil, so that it contacts the anchor rod and the surrounding rock and reacts. For the top fast anchoring drug coil, the top of the anchor rod can be used to destroy the drug coil, so that it contacts the surrounding rock and the anchor rod and an anchoring reaction occurs; for the hollow slow anchoring drug coil, during the rotation of the anchor rod, since the stirring device is attached to the rod body, the stirring device will rotate with the anchor rod body, while the slow anchoring drug coil is only wrapped on the outside of the stirring device and there is no bonding effect. Therefore, the centrifugal force generated during the rotation of the anchor rod body can drive the stirring piece on the stirring device to rotate, thereby destroying the slow anchoring drug coil, so that it contacts the surrounding rock and the anchor rod and an anchoring reaction occurs; S4: After the initial anchoring of the top of the anchor bolt is completed, with the anchoring reaction of the drug coil, the anchoring speed of the top fast anchoring drug coil is faster than that of the rod body slow anchoring drug coil, and the top of the anchor bolt is combined with the surrounding rock quickly. The construction personnel monitor the anchoring force of the top with reference to relevant construction specifications. After determining that the anchoring force strength of the top of the anchor bolt meets the standard, since the hollow slow anchoring drug coil on the anchor rod body is still in the anchoring reaction process, the anchoring force has not yet reached the standard. The construction personnel use the anchor drilling rig to tension the anchor bolt at the free end, apply prestress with reference to the construction specifications, and finally install the anchor pad and fixing nut to complete the prestress locking and anchor bolt fixing. At this point, the installation of a single adaptive multi-point anchoring prestressed anchor bolt is completed.

[0028] Therefore, the present invention adopts the above-mentioned adaptive multi-point anchoring prestressed anchor rod and method, and adopts distributed anchoring and asynchronous anchoring methods according to the distribution of surrounding rock in the support range to improve the stress condition of the anchor rod body and the surrounding rock reinforcement effect. The hollow slow anchoring type medicine coil is distributed at the corresponding position of the rod body, and comprises two parts, a medicine coil and a stirring device. The medicine coil stirring can be realized by centrifugal force during the rotation of the anchor rod. The fast anchoring type medicine coil is located at the top of the anchor rod. The distributed arrangement can improve the stress distribution of the anchor rod body, better adapt to the deformation of the surrounding rock, and ensure the stability of the surrounding rock. Since the anchoring speed of the top medicine coil is faster than that of the rod body medicine coil, after the initial anchoring of the top of the anchor rod is completed, prestress can be applied to the anchor rod, thereby further improving the bearing capacity of the anchor rod support structure, thereby ensuring the safety and stability of the tunnel structure.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the method scheme of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary method personnel in the field should understand that they can still modify or replace the method scheme of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified method scheme to deviate from the spirit and scope of the method scheme of the present invention.

Claims

1. An adaptive multi-point anchoring prestressed anchor rod, characterized in that: It includes a fixed retaining ring arranged in a borehole and an anchor pad arranged below the borehole, a quick anchoring type medicine coil is arranged at the top of the borehole, a hollow slow anchoring type medicine coil is arranged on the fixed retaining ring, a fixing nut is arranged below the anchor pad, and the anchor rod body passes through the fixing nut, the anchor pad, the fixed retaining ring and the hollow slow anchoring type medicine coil in sequence and extends to the inside of the borehole.

2. The adaptive multi-point anchoring prestressed anchor rod according to claim 1, characterized in that: The number of the fixed retaining ring and the hollow slow anchoring type medicine roll is not fixed, and the fixed retaining ring is a hollow rigid gasket.

3. The adaptive multi-point anchoring prestressed anchor rod according to claim 1, characterized in that: The hollow slow anchoring medicine roll comprises a stirring device and a slow anchoring medicine roll wrapped outside the stirring device. The stirring device is a single-layer adhesive film. The stirring device is fixedly connected to the anchor rod body by gluing.

4. The adaptive multi-point anchoring prestressed anchor rod according to claim 3, characterized in that: A plurality of stirring blades are symmetrically arranged on the outer walls of both sides of the stirring device, and the stirring blades are movably connected to the stirring device by means of a spherical hinge.

5. The adaptive multi-point anchoring prestressed anchor rod according to claim 1, characterized in that: The anchor rod body is fixedly connected to the fixing retaining ring by bonding, and the anchor rod body is fixedly connected to the fixing nut by a threaded structure.

6. A method for implementing an adaptive multi-point anchoring prestressed anchor rod according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: According to the engineering geological survey report and combined with the geological detection technology of the construction site, determine the boundary position of different types of surrounding rocks; S2: Place the quick anchoring coil in the drill hole, and install the hollow slow anchoring coil and fixed retaining ring at the corresponding position of the rod; S3: Use an anchor drilling rig to push the anchor rod body and the drug coil into the borehole until they come into contact with the deep surrounding rock, rotate the anchor rod body and stir the drug coil to make it contact with the anchor rod and the surrounding rock and react; S4: After the initial anchoring of the top of the anchor is completed, the anchor is tensioned at the free end using an anchor drill, and the anchor pad and fixing nut are installed to complete the prestressed locking and anchor installation.

7. The method for implementing the adaptive multi-point anchoring prestressed anchor rod according to claim 6, characterized in that: In step S2, a hollow slow anchoring type medicine coil and a fixed retaining ring are installed at corresponding positions of the rod body, which specifically includes the following steps: S21: Install the fixed retaining ring at the corresponding position of the anchor rod body; S22: Paste the stirring device around the rod body and onto the fixed retaining ring; S23: Wrap the slowly anchoring medicine around the rod body and wrap it around the outside of the stirring device.

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