A tunnel anchor rod construction method

Abstract

The application discloses a tunnel anchor rod construction method, comprising the following steps: installing the tunnel anchor rod in a drilling hole and carrying out gap grouting between an anchoring section and the drilling hole; after gap grouting between the anchoring section and the drilling hole is completed and reaches a design requirement strength, injecting filling material into a gap between the anchor rod sleeve and the prestressed section; after filling material injection between the anchor rod sleeve and the prestressed section is completed and reaches a design requirement strength, carrying out gap grouting between the anchor rod sleeve and the drilling hole; after gap grouting between the anchor rod sleeve and the drilling hole is completed and reaches a design requirement strength, destroying the filling material, and completing anchor rod supporting work. The application solves the technical problems of high construction cost, great operation difficulty and unguaranteed quality of tunnel anchor rods in the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnels and underground engineering, and particularly relates to a tunnel anchor rod construction method. BACKGROUND

[0002] With the vigorous development of the transportation industry in China, the problems in tunnel construction are increasingly prominent, such as faults, soft rock, swelling rock, goaf, karst, etc., and the safety of tunnel structures faces major challenges. As a part of the tunnel support structure, anchor rods have great advantages in technology and economy, and can be applied to different working conditions. When facing engineering problems such as soft rock large deformation and rock burst, researchers and designers often recommend using prestressed anchor rods for support, and their good support characteristics have been widely recognized by the academic community.

[0003] The current tunnel anchor rod installation process mainly includes the following steps: drilling and installing anchor rods, grouting the anchoring section, after the grout is filled, the anchor rod puller oil top sleeve is placed on the anchor head, a steel plate and a nut are added to the end of the anchor head, the oil top is fixed, and prestress is then applied. After the anchor rod puller is used to apply prestress to the design requirement, a period of time is maintained, and then locking work is performed, that is, the steel plate nut at the root of the anchor head is tightened with a torque wrench, and the tightening torque is tightened. The steel plate, puller, and excess anchor head are removed, the hole is closed, and the anchor rod construction is completed. This method requires a smooth action surface, and the construction of anchor rods in the arch range is extremely difficult, making it difficult to ensure quality and efficiency, and there is a high safety risk.

[0004] In view of this, a prefabricated tunnel prestressed anchor rod is disclosed in Chinese patent CN115853566A, which can be directly installed and used on site, is simple to operate, and has good prestressed state, but requires the production of prestressed anchor rods in advance, resulting in increased production costs.

[0005] Therefore, there is an urgent need for a tunnel anchor rod construction method that has low production costs, small operation difficulty, and can ensure construction quality. SUMMARY

[0006] The present application aims to overcome the above technical deficiencies and provide a tunnel anchor rod construction method that solves the technical problems of high construction cost, large operation difficulty, and unguaranteed quality of tunnel anchor rods in the prior art.

[0007] To achieve the above technical purpose, the present application adopts the following technical solution:

[0008] A tunnel anchor rod construction method for installing a tunnel anchor rod, the tunnel anchor rod comprising an anchoring section and a prestressed section, a partition plate being installed between the anchoring section and the prestressed section, a grouting hole being formed in the partition plate, and an anchor rod sleeve being sleeved on the prestressed section, the anchor rod sleeve and the prestressed section having a gap therebetween, the construction method comprising the following steps:

[0009] installing the tunnel anchor rod in the borehole and performing the grouting between the anchoring section and the borehole;

[0010] after the grouting between the anchoring section and the borehole is completed and reaches the required design strength, injecting the filling material into the gap between the anchor rod sleeve and the prestressed section;

[0011] after the filling material injection between the anchor rod sleeve and the prestressed section is completed and reaches the required design strength, performing the grouting between the anchor rod sleeve and the borehole;

[0012] after the grouting between the anchor rod sleeve and the borehole is completed and reaches the required design strength, destroying the filling material to complete the anchor rod support work.

[0013] In some embodiments, the installing the tunnel anchor rod in the borehole and performing the grouting between the anchoring section and the borehole comprises:

[0014] installing the tunnel anchor rod in the borehole, inserting a grouting pipe and a grout outlet pipe between the anchoring section and the borehole through the grouting hole;

[0015] grouting the gap between the anchoring section and the borehole through the grouting pipe;

[0016] judging whether the grouting between the anchoring section and the borehole is completed through the grout outlet pipe.

[0017] In some embodiments, the judging whether the grouting between the anchoring section and the borehole is completed through the grout outlet pipe comprises:

[0018] when the distal end of the grout outlet pipe grouts, it is determined that the grouting between the anchoring section and the borehole is completed, otherwise, the grouting of the grouting pipe is maintained.

[0019] In some embodiments, the injecting the filling material into the gap between the anchor rod sleeve and the prestressed section after the grouting between the anchoring section and the borehole is completed and reaches the required design strength comprises:

[0020] after the grouting between the anchoring section and the borehole is completed and reaches the required design strength, inserting a liquid injection pipe and a liquid outlet pipe in the gap between the anchor rod sleeve and the prestressed section;

[0021] injecting the filling material into the gap between the anchor rod sleeve and the prestressed section through the liquid injection pipe;

[0022] judging whether the injection into the gap between the anchor rod sleeve and the prestressed section is completed through the liquid outlet pipe.

[0023] In some embodiments, the judging whether the gap between the anchor rod sleeve and the prestressed section is injected completely through the outflow pipe comprises:

[0024] When the distal end of the outflow pipe outflows, it is determined that the gap between the anchor rod sleeve and the prestressed section is injected completely, otherwise, the injection of the injection pipe is maintained.

[0025] In some embodiments, the filling material is inorganic material with fluidity and compressive strength after solidification meeting preset conditions.

[0026] In some embodiments, the filling material is material that can be destroyed by electricity or mechanical structure.

[0027] In some embodiments, after the filling material between the anchor rod sleeve and the prestressed section is injected completely and reaches the design required strength, the annular gap between the anchor rod sleeve and the borehole is grouted, comprising:

[0028] After the filling material between the anchor rod sleeve and the prestressed section is injected completely and reaches the design required strength, the grouting pipe and the outflow pipe are inserted into the annular gap between the anchor rod sleeve and the borehole;

[0029] The annular gap between the anchor rod sleeve and the borehole is grouted through the grouting pipe;

[0030] Whether the grouting of the annular gap between the anchor rod sleeve and the borehole is completed is judged through the outflow pipe.

[0031] In some embodiments, the judging whether the grouting of the annular gap between the anchor rod sleeve and the borehole is completed through the outflow pipe comprises:

[0032] When the distal end of the outflow pipe outflows, it is determined that the grouting of the annular gap between the anchor rod sleeve and the borehole is completed, otherwise, the grouting of the grouting pipe is maintained.

[0033] In some embodiments, the method further comprises:

[0034] After the tunnel anchor rod is installed in the borehole, the tunnel anchor rod is locked in the borehole through the locking device, and after the anchor rod supporting operation is completed, the locking device is removed.

[0035] Compared with the prior art, the tunnel anchor rod construction method provided by the application can directly use common tunnel anchor rods for construction, pre-applies prestress to the anchor rod body by first fixing the anchoring section, then injecting filling material between the anchor rod sleeve and the prestressed section, then performing gap grouting between the anchor rod sleeve and the borehole, and then destroying the filling material after grouting is completed, so that the prestress borne by the anchor rod is transferred to the surrounding rock, thereby eliminating the need for pre-preparing prestressed anchor rods, improving construction efficiency, eliminating the need for complex operations and special equipment, and being suitable for installation of prestressed anchor rods that are axially directed towards the center of the tunnel, and having high construction safety. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a flowchart of the tunnel anchor rod construction method provided by the embodiment of the application;

[0037] Figure 2 is a schematic diagram of an embodiment of the tunnel anchor rod provided by the embodiment of the application. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the application clearer, the application is further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and do not limit the application.

[0039] Please refer to Figure 1 and Figure 2 The tunnel anchor rod construction method provided by the application is used for installing a tunnel anchor rod, the tunnel anchor rod comprises an anchoring section 1 and a prestressed section 2, a partition plate 3 is installed between the anchoring section 1 and the prestressed section 2, a grouting hole 3a is formed in the partition plate 3, an anchor rod sleeve 4 is sleeved on the prestressed section 2, and a gap is formed between the anchor rod sleeve 4 and the prestressed section 2.

[0040] Optionally, the construction method comprises the following steps:

[0041] S100, installing the tunnel anchor rod in the borehole and performing gap grouting between the anchoring section and the borehole;

[0042] S200, after the gap grouting between the anchoring section and the borehole is completed and reaches the design requirement strength, injecting filling material into the gap between the anchor rod sleeve and the prestressed section;

[0043] S300, after the filling material injection between the anchor rod sleeve and the prestressed section is completed and reaches the design requirement strength, performing gap grouting between the anchor rod sleeve and the borehole;

[0044] S400, after the gap grouting between the anchor rod sleeve and the borehole is completed and reaches the design requirement strength, destroying the filling material, and completing the anchor rod support work.

[0045] In the embodiment, the common tunnel anchor rod can be directly used for construction, the anchor section is first fixed, then the filling material is injected between the anchor rod sleeve and the prestressed section, the prestress is applied to the anchor rod body in advance, the gap grouting is performed between the anchor rod sleeve and the borehole, after the grouting is completed, the filling material is damaged, so that the prestress of the anchor rod is transferred to the surrounding rock, and then the prestress anchor rod does not need to be prefabricated in advance, the construction efficiency is high, the special equipment is not needed, and the construction safety is high.

[0046] In some embodiments, the step S100 specifically comprises:

[0047] S110, installing the tunnel anchor rod in the borehole, and inserting the grouting pipe and the slurry outlet pipe between the anchor section and the borehole through the grouting hole;

[0048] S120, grouting the gap between the anchor section and the borehole through the grouting pipe;

[0049] S130, judging whether the gap grouting between the anchor section and the borehole is completed through the slurry outlet pipe.

[0050] In the embodiment, the tunnel anchor rod is first installed in the borehole, and then the grouting is performed through the grouting pipe. Due to the existence of the partition plate, the gap grouting between the anchor section and the borehole can be first performed, and the injected slurry does not fall into the prestressed section. After the grouting, the slurry outlet condition of the slurry outlet pipe is observed, and then it can be judged whether the gap between the anchor section and the borehole is filled with slurry. The method is simple and convenient.

[0051] In some embodiments, the step S130 specifically comprises:

[0052] When the distal end of the slurry outlet pipe is slurry, it is determined that the gap grouting between the anchor section and the borehole is completed, otherwise, the grouting of the grouting pipe is maintained.

[0053] In the embodiment, when the gap between the anchor section and the borehole is filled with slurry, if the slurry continues to be injected at this time, the slurry will overflow through the slurry outlet pipe. Therefore, whether the grouting is completed is judged according to the slurry outlet condition of the slurry outlet pipe. When the slurry flows out from the distal end of the slurry outlet pipe, it indicates that the gap between the anchor section and the borehole is filled, otherwise, the injection of the slurry needs to be continuously performed.

[0054] It should be noted that the distal end of the slurry outlet pipe in the embodiment of the application refers to the end of the slurry outlet pipe far away from the anchor section 1.

[0055] In some embodiments, the step S200 specifically comprises:

[0056] S210, inserting a liquid injection pipe and a liquid outlet pipe into the gap between the anchor rod sleeve and the prestressed segment after the grouting of the gap between the anchor segment and the borehole channel is completed and reaches the design requirement strength;

[0057] S220, injecting the filling material into the gap between the anchor rod sleeve and the prestressed segment through the liquid injection pipe;

[0058] S230, judging whether the injection into the gap between the anchor rod sleeve and the prestressed segment is completed through the liquid outlet pipe.

[0059] In the embodiment, after the grouting of the anchor segment is completed, the liquid injection into the gap between the anchor rod sleeve and the prestressed segment is performed, and after the filling material is injected, the liquid outlet condition of the liquid outlet pipe is observed to further judge whether the gap between the anchor rod sleeve and the prestressed segment is filled with the filling material, which is simple and convenient.

[0060] In some embodiments, the step S230 specifically comprises:

[0061] When the distal end of the liquid outlet pipe has liquid outlet, it is determined that the injection into the gap between the anchor rod sleeve and the prestressed segment is completed, otherwise, the liquid injection of the liquid injection pipe is kept.

[0062] In the embodiment, after the gap between the anchor rod sleeve and the prestressed segment is filled with the filling material, if the filling material is continuously injected at this time, the filling material will overflow through the liquid outlet pipe. Therefore, the embodiment judges whether the filling material is completed through the liquid outlet condition of the liquid outlet pipe. When the distal end of the liquid outlet pipe has liquid outlet, it indicates that the gap between the anchor rod sleeve and the prestressed segment has been filled, otherwise, the injection of the filling material needs to be continuously performed.

[0063] In some embodiments, the filling material adopts inorganic material with fluidity and compressive strength after solidification meeting preset conditions, which can better grip the anchor rod after solidification and give the prestressed segment to apply prestress in advance.

[0064] In some embodiments, the filling material is material that can be damaged by electricity or mechanical structure, which can be damaged under the action of electric current or mechanical structure, and then eliminate the gripping effect on the prestressed segment to make the prestress transfer to the surrounding rock.

[0065] In some embodiments, the step S300 specifically comprises:

[0066] S310, inserting a grouting pipe and a grout outlet pipe into the gap between the anchor rod sleeve and the borehole channel after the injection of the filling material between the anchor rod sleeve and the prestressed segment is completed and reaches the design requirement strength;

[0067] S320, grouting the gap between the anchor rod sleeve and the borehole channel through the grouting pipe;

[0068] S330, judging whether the grouting of the gap between the anchor rod sleeve and the borehole channel is completed through the grouting pipe.

[0069] In the embodiment, when the filling material solidifies to the required degree, prestress can be applied to the prestress section in advance, and then the grouting of the gap between the anchor rod sleeve and the borehole channel can be performed. After the grout is injected, the grouting of the gap between the anchor rod sleeve and the borehole channel can be judged according to the grouting of the grouting pipe, which is simple and convenient.

[0070] In some embodiments, the step S330 specifically comprises:

[0071] When the distal end of the grouting pipe grouts, it is determined that the grouting of the gap between the anchor rod sleeve and the borehole channel is completed, otherwise, the grouting of the grouting pipe is maintained.

[0072] In the embodiment, when the gap between the anchor rod sleeve and the borehole channel is filled with the grout, if the grout is continuously injected, the grout will overflow through the grouting pipe. Therefore, the embodiment judges whether the grouting is completed according to the grouting of the grouting pipe. When the grout flows out from the distal end of the grouting pipe, it indicates that the gap between the anchor rod sleeve and the borehole channel is filled, otherwise, the grout injection needs to be continuously performed.

[0073] In some embodiments, the method further comprises:

[0074] After the tunnel anchor rod is installed in the borehole channel, the tunnel anchor rod is locked in the borehole channel through the locking device. After the anchor rod support operation is completed, the locking device is removed.

[0075] In the embodiment, the locking device can comprise a washer and a locking nut. The tunnel anchor rod is locked in the borehole channel through the locking nut and the washer. The washer is provided with a plurality of holes. Optionally, the number of the holes is six. Three of the holes are respectively used for the grouting pipe of the anchoring section, the grouting pipe of the prestress section and the grouting pipe, and the other three of the holes are respectively used for the grouting pipe of the anchoring section, the grouting pipe of the prestress section and the grouting pipe, thereby facilitating the grouting and grouting and providing convenience for construction.

[0076] In summary, the tunnel anchor rod construction method provided by the application can directly use common tunnel anchor rods for construction, the anchor rod body is pre-stressed by first fixing the anchoring section, then injecting filling material between the anchor rod sleeve and the pre-stressed section, then performing gap grouting between the anchor rod sleeve and the borehole, and then destroying the filling material after grouting is completed, so that the pre-stress on the anchor rod is transferred to the surrounding rock, thereby eliminating the need for pre-preparing pre-stressed anchor rods, and the construction efficiency is high, no complex operation and special equipment are required, and the method is suitable for pre-stressed anchor rod installation in the axial direction of the tunnel center, and has high construction safety.

[0077] The specific embodiments of the application described above do not constitute a limitation on the protection scope of the application. Any various other corresponding changes and modifications made according to the technical concept of the application shall be included in the protection scope of the claims of the application.

Claims

1. A method of tunnel anchor construction, characterized in that, The application relates to a construction method for installing a tunnel anchor rod, wherein the tunnel anchor rod comprises an anchoring section and a prestressed section, a partition plate is arranged between the anchoring section and the prestressed section, a grouting hole is arranged on the partition plate, an anchor rod sleeve is arranged on the prestressed section, a gap is arranged between the anchor rod sleeve and the prestressed section, and the construction method comprises the following steps. The tunnel anchor rod is installed in a drilling hole, and the gap grouting between the anchoring section and the drilling hole is carried out; After the gap grouting between the anchoring section and the drilling hole is completed and reaches the design requirement strength, the gap between the anchor rod sleeve and the prestressed section is injected with filling material; After the filling material injection between the anchor rod sleeve and the prestressed section is completed and reaches the design requirement strength, the gap grouting between the anchor rod sleeve and the drilling hole is carried out; After the gap grouting between the anchor rod sleeve and the drilling hole is completed and reaches the design requirement strength, the filling material is destroyed, and the anchor rod supporting work is completed.

2. A method of tunnel anchor construction according to claim 1, characterised in that, The tunnel anchor rod is installed in a drilling hole, and the gap grouting between the anchoring section and the drilling hole is carried out, which comprises the following steps. The tunnel anchor rod is installed in a drilling hole, and a grouting pipe and a grouting outlet pipe are inserted into the gap between the anchoring section and the drilling hole through the grouting hole; The gap grouting between the anchoring section and the drilling hole is carried out through the grouting pipe; Whether the gap grouting between the anchoring section and the drilling hole is completed is judged through the grouting outlet pipe.

3. A method of tunnel anchor construction according to claim 2, characterised in that, Whether the gap grouting between the anchoring section and the drilling hole is completed is judged through the grouting outlet pipe, which comprises the following steps. When the distal end of the grouting outlet pipe grouts, it is determined that the gap grouting between the anchoring section and the drilling hole is completed, otherwise, the grouting of the grouting pipe is kept.

4. The method of claim 1, wherein, After the gap grouting between the anchoring section and the drilling hole is completed and reaches the design requirement strength, the gap between the anchor rod sleeve and the prestressed section is injected with filling material, which comprises the following steps. After the gap grouting between the anchoring section and the drilling hole is completed and reaches the design requirement strength, a liquid injection pipe and a liquid outlet pipe are inserted into the gap between the anchor rod sleeve and the prestressed section; The gap grouting between the anchoring section and the drilling hole is carried out through the grouting pipe; Whether the gap grouting between the anchoring section and the drilling hole is completed is judged through the grouting outlet pipe.

5. A method of tunnel anchor construction according to claim 4, wherein, Whether the gap grouting between the anchoring section and the drilling hole is completed is judged through the grouting outlet pipe, which comprises the following steps. When the distal end of the grouting outlet pipe grouts, it is determined that the gap grouting between the anchoring section and the drilling hole is completed, otherwise, the grouting of the grouting pipe is kept.

6. The method of tunneling a rock bolt according to claim 1, wherein, The filling material is inorganic material with flowability and compressive strength meeting preset conditions after solidification.

7. The method of tunneling a rock bolt according to claim 1, wherein, The filling material is material which can be destroyed by electricity or mechanical structure.

8. The method of tunneling a rock bolt according to claim 1, wherein, After the filling material injection between the anchor rod sleeve and the prestressed section is completed and reaches the design requirement strength, the gap grouting between the anchor rod sleeve and the drilling hole is carried out, which comprises the following steps. After the filling material injection between the anchor rod sleeve and the prestressed section is completed and reaches the design requirement strength, a grouting pipe and a grouting outlet pipe are inserted into the gap between the anchor rod sleeve and the drilling hole; The gap grouting between the anchoring section and the drilling hole is carried out through the grouting pipe; The method comprises judging whether the space grouting between the anchor rod sleeve and the borehole tunnel is completed through the out-grouting pipe.

9. A tunnel anchor construction method according to claim 8, characterised in that, The method comprises judging whether the space grouting between the anchor rod sleeve and the borehole tunnel is completed through the out-grouting pipe. When the distal end of the out-grouting pipe grouts, it is determined that the space grouting between the anchor rod sleeve and the borehole tunnel is completed, otherwise, the grouting of the grouting pipe is maintained.

10. The method of tunneling a rock bolt according to claim 1, wherein, The method further comprises: After the tunnel anchor rod is installed in the borehole tunnel, the tunnel anchor rod is locked in the borehole tunnel through a locking device, and after the anchor rod support operation is completed, the locking device is removed.

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