Advanced reinforcement method suitable for broken surrounding rock anchoring section

Abstract

The invention belongs to the technical field of broken surrounding rock anchoring section reinforcement, and particularly relates to an advanced reinforcing method suitable for a broken surrounding rock anchoring section, which comprises the following steps: S1, manufacturing an advanced small guide pipe, S2, positioning according to a designed circumferential distance and an externally inserted corner mark, and forming a hole through an air drill and a hydraulic drilling machine, S3, cleaning the hole, S4, checking and accepting the drilled hole, and detecting the hole depth, angle, distance and hole wall integrity. The advanced reinforcing mode is adjusted according to the situation that a normal construction section enters a broken surrounding rock anchoring section, slip collapse and chipping of a tunnel face vault are effectively controlled, in addition, the section is enlarged, advanced reinforcing and grouting are conducted through the advanced small guide pipe, the loose surrounding rock is effectively stabilized and loosened, an overall structure is formed, a loose ring is reinforced in advance, and the construction efficiency is improved. Safety accidents caused by falling of stones are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of reinforcement of anchor sections under broken surrounding rocks, in particular to an advanced reinforcement method suitable for anchor sections under broken surrounding rocks. Background Art

[0002] Currently, railway tunnel construction has entered its peak phase. With the increase in the design speed of trains, the quality of railway tunnel construction has also been significantly improved. Under the current railway construction situation, high standards and high requirements are indispensable. With the requirements of the four electrical specialties in high-speed railway tunnel construction, various electrical equipment need to be installed in the tunnel. Without affecting the train operation, the tunnel section can be continuously changed to achieve the purpose. The existing design and construction do not have advanced reinforcement measures for the normal section to enter the anchor section and expand the section. Due to improper reinforcement measures or premature failure after the expansion of the section, the arch surrounding rock collapses at the junction of the anchor section, resulting in safety accidents and affecting the construction progress. Therefore, it is urgent to provide an advanced reinforcement method suitable for the anchor section of the broken surrounding rock. Summary of the Invention

[0003] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid blurring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0004] Therefore, the purpose of the present invention is to provide a method for advance reinforcement of the anchor section under the broken surrounding rock, which can adjust the advance reinforcement form according to the normal construction section entering the anchor section under the broken surrounding rock, effectively control the collapse and falling of the arch crown of the heading face, and expand the section to use advance small pipes for advance reinforcement and grouting, effectively stabilize the loose surrounding rock, form an overall structure, reinforce the loose circle in advance, and avoid safety accidents caused by falling stones.

[0005] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0006] A method for pre-reinforcement of an anchor section under broken surrounding rock, comprising the following steps:

[0007] S1. To make the advanced small conduit, select φ45-φ50mm hot-rolled seamless steel pipe and cut it according to the designed length;

[0008] S2. Drill holes, locate them according to the designed circumferential spacing and external angle marks, and use pneumatic drills or hydraulic drills to drill holes;

[0009] S3. Clean the hole, blow out the residue in the hole with a high-pressure air pipe, and check the patency of the hole to see if there is any debris or mud blockage;

[0010] S4. Drilling acceptance, hole depth, angle, spacing and hole wall integrity inspection;

[0011] S5. Jack the small conduit. Apply lubricant to the conduit and slowly jack it in using a pneumatic pick or hydraulic jacking device to ensure the designed exposed length is 10-15 cm.

[0012] S6. Install the grouting head, expose the conduit, connect the stop valve and grouting pipeline, and use fast-hardening cement to seal the orifice gap;

[0013] S7. Grouting: When conducting pre-grouting, a water pressure test should be conducted before grouting to check whether the mechanical equipment is normal and whether the pipeline connection is correct. In order to speed up the grouting speed and maximize the efficiency of the equipment, group grouting can be adopted, 3-5 pipes at a time, and the grouting should be terminated when the grouting volume reaches the designed grouting volume or the grouting pressure reaches the designed final pressure;

[0014] S8. Seal. After grouting is completed, close the stop valve, remove the pipeline, and seal the tail end of the catheter with a steel plate.

[0015] As a preferred solution of the advance reinforcement method suitable for the anchor section under the broken surrounding rock described in the present invention, wherein: in the step S1, the specifications of the advance small guide tube are: hot-rolled seamless steel pipe, outer diameter 42mm, wall thickness 3.5mm, grouting holes are set in the pipe body, hole diameter 6mm, hole spacing 15cm, arranged in a plum blossom shape, the front end is processed into a cone, and the tail length is not less than 100cm, serving as a grouting stop section without drilling.

[0016] As a preferred solution of the method for pre-reinforcement of the anchor section under the broken surrounding rock of the present invention, in step S4, if the drilling is unqualified, the process returns to step S3 and re-drills.

[0017] As a preferred solution of the advance reinforcement method for the anchor section under the broken surrounding rock described in the present invention, wherein: in the step S5, if it is found that the resistance is too large during the jacking process, it is necessary to exit and re-clean the hole before performing the jacking operation.

[0018] As a preferred solution of the advance reinforcement method for the lower anchor section of broken surrounding rock described in the present invention, wherein: in the step S5, 3m before entering the lower anchor section, the advance reinforcement is set at 15°, and the advance reinforcement is set at 4m to meet the overlap length. 1.8m before entering the lower anchor section, the advance reinforcement is set at an angle of 23° when the cross section of the arch is expanded to the lower anchor section, and the advance reinforcement is set at 4m to meet the overlap length.

[0019] As a preferred solution of the advance reinforcement method for the anchor section under the broken surrounding rock described in the present invention, in which: in the step S5, the arch crown is used as the center line, and the other side is advanced by 4m at 15° to meet the overlap length. When entering the anchor section, the second arch frame can be used for advance construction, and the advance length is 3.5m.

[0020] As a preferred solution of the advance reinforcement method for the lower anchor section of broken surrounding rock described in the present invention, wherein: in the step S5, the construction of the lower anchor section is equivalent to the top construction of the auxiliary tunnel entering the main tunnel, and the spacing of the advance small guide tubes is adjusted according to the on-site construction, and it is appropriate to set it 1m above the arch foot of the upper step.

[0021] As a preferred solution of the advance reinforcement method for the anchor section under the broken surrounding rock described in the present invention, wherein: in the step S7, the changes in the grouting pressure and the discharge volume of the grouting pump should be observed at any time during the grouting process, the grouting situation should be analyzed, pipe blockage, paddle running, and grout leakage should be prevented, and grouting records should be kept to analyze the grouting effect.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Adjust the advance reinforcement method for the anchor section under the broken surrounding rock in the normal construction section to effectively control the collapse and falling of the arch crown of the tunnel face;

[0024] 2. Expand the cross section and use the advanced small pipe to reinforce and grout in advance to effectively stabilize the loose surrounding rock and form an integral structure;

[0025] 3. Reinforce the loose circle in advance to avoid safety accidents caused by falling stones;

[0026] 4. There are many anchor sections, which ensure safe and stable construction to avoid affecting the overall construction progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort. Among them:

[0028] Figure 1 This is a schematic block diagram of the steps of the advanced reinforcement method of the present invention;

[0029] Figure 2 This is the design drawing of the present invention with an external insertion angle of 15° for the advanced anchor rod;

[0030] Figure 3 This is the design drawing of the advanced anchor rod with external insertion angles of 15° and 23°;

[0031] Figure 4 For the present invention Figure 3 Detailed image;

[0032] Figure 5 Design drawings of 3.5m and 4m advance anchor rods of the present invention;

[0033] Figure 6 This is the pre-grouting parameter table of the present invention. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] Next, the present invention is described in detail with reference to schematic diagrams. For ease of illustration, cross-sectional views of device structures may be partially enlarged and not to scale when describing the embodiments of the present invention. Furthermore, the schematic diagrams are merely illustrative and should not limit the scope of protection of the present invention. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.

[0037] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0038] The present invention provides a method for pre-reinforcement of the anchor section under the broken surrounding rock. The pre-reinforcement form is adjusted according to the normal construction section entering the anchor section under the broken surrounding rock, effectively controlling the collapse and falling of the tunnel face vault. In addition, the expanded section is reinforced and grouting is carried out in advance using a small pre-reinforcement pipe, effectively stabilizing the loose surrounding rock to form an integral structure, and reinforcing the loose circle in advance to avoid safety accidents caused by falling rocks. Please refer to Figure 1-6 , including the following steps:

[0039] S1. To make the advanced small conduit, select φ45-φ50mm hot-rolled seamless steel pipe and cut it according to the designed length;

[0040] S2. Drill holes, locate them according to the designed circumferential spacing and external angle marks, and use pneumatic drills or hydraulic drills to drill holes;

[0041] S3. Clean the hole, blow out the residue in the hole with a high-pressure air pipe, and check the patency of the hole to see if there is any debris or mud blockage;

[0042] S4. Drilling acceptance, hole depth, angle, spacing and hole wall integrity inspection;

[0043] S5. Jack the small conduit. Apply lubricant to the conduit and slowly jack it in using a pneumatic pick or hydraulic jacking device to ensure the designed exposed length is 10-15 cm.

[0044] S6. Install the grouting head, expose the conduit, connect the stop valve and grouting pipeline, and use fast-hardening cement to seal the orifice gap;

[0045] S7. Grouting: When conducting pre-grouting, a water pressure test should be conducted before grouting to check whether the mechanical equipment is normal and whether the pipeline connection is correct. In order to speed up the grouting speed and maximize the efficiency of the equipment, group grouting can be adopted, 3-5 pipes at a time, and the grouting should be terminated when the grouting volume reaches the designed grouting volume or the grouting pressure reaches the designed final pressure;

[0046] S8. Plugging: After grouting is completed, close the stop valve, remove the pipeline, and weld the tail end of the conduit closed with a steel plate;

[0047] Further:

[0048] In step S1, the specifications of the advanced small conduit are: hot-rolled seamless steel pipe, outer diameter 42mm, wall thickness 3.5mm, grouting holes are set in the pipe body, hole diameter 6mm, hole spacing 15cm, arranged in a plum blossom shape, the front end is processed into a tapered shape, and the tail length is not less than 100cm, which serves as a grouting stop section without drilling;

[0049] In step S4, if the drilling is unqualified, return to step S3 and drill again;

[0050] In step S5, if the resistance is too great during the jacking process, it is necessary to exit and clean the hole again before continuing the jacking operation;

[0051] In step S5, 3 m before entering the lower anchor section, the lead angle is 15°, and the lead angle is 4 m to meet the overlap length. 1.8 m before entering the lower anchor section, the lead angle is 23° when measuring the expanded section of the arch downward anchor section, and the lead angle is 4 m to meet the overlap length.

[0052] In step S5, the arch is positioned at an angle of 15° on the other side of the centerline and is advanced by 4 meters to meet the overlap length. When the second arch frame is advanced into the anchor section, the advance length is 3.5 meters.

[0053] In step S5, the construction of the anchoring section is equivalent to the construction of the auxiliary tunnel into the main tunnel. The spacing of the advance small guide tubes is adjusted according to the on-site construction, and it is preferably set 1m above the arch foot of the upper step;

[0054] See also Figure 6In step S7, during the grouting process, the changes in the grouting pressure and the grouting pump discharge volume should be observed at any time to analyze the grouting situation, prevent pipe blockage, paddle movement, and grout leakage, and keep grouting records to analyze the grouting effect;

[0055] Working principle: When in use, the invention adjusts the advance reinforcement form for the anchor section under the broken surrounding rock according to the normal construction section, effectively controlling the collapse and falling of the arch of the heading face, and the expanded section uses the advance small guide tube for advance reinforcement and grouting, effectively stabilizing the loose surrounding rock, forming an overall structure, and reinforcing the loose circle in advance to avoid safety accidents caused by falling stones.

[0056] Although the present invention has been described above with reference to embodiments, various modifications may be made thereto and equivalent components may be substituted without departing from the scope of the present invention. In particular, as long as there are no structural conflicts, the various features of the embodiments disclosed herein may be combined with each other in any manner, and the omission of an exhaustive description of such combinations in this specification is solely for the sake of space and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for pre-reinforcement of anchor sections under broken surrounding rock, characterized in that: The steps are as follows: S1. To make the advanced small conduit, select φ45-φ50mm hot-rolled seamless steel pipe and cut it according to the designed length; S2. Drill holes, locate them according to the designed circumferential spacing and external angle marks, and use pneumatic drills or hydraulic drills to drill holes; S3. Clean the hole, blow out the residue in the hole with a high-pressure air pipe, and check the patency of the hole to see if there is any debris or mud blockage; S4. Drilling acceptance, hole depth, angle, spacing and hole wall integrity inspection; S5. Jack the small conduit. Apply lubricant to the conduit and slowly jack it in using a pneumatic pick or hydraulic jacking device to ensure the designed exposed length is 10-15 cm. S6. Install the grouting head, expose the conduit, connect the stop valve and grouting pipeline, and use fast-hardening cement to seal the orifice gap; S7. Grouting: When conducting pre-grouting, a water pressure test should be conducted before grouting to check whether the mechanical equipment is normal and whether the pipeline connection is correct. In order to speed up the grouting speed and maximize the efficiency of the equipment, group grouting can be adopted, 3-5 pipes at a time, and the grouting should be terminated when the grouting volume reaches the designed grouting volume or the grouting pressure reaches the designed final pressure; S8. Seal. After grouting is completed, close the stop valve, remove the pipeline, and seal the tail end of the catheter with a steel plate.

2. The method for pre-reinforcement of anchor sections under broken surrounding rocks according to claim 1, characterized in that: In step S1, the specifications of the advance small conduit are: hot-rolled seamless steel pipe, outer diameter 42mm, wall thickness 3.5mm, grouting holes are set on the pipe body, hole diameter 6mm, hole spacing 15cm, arranged in a plum blossom shape, the front end is processed into a cone, and the tail length is not less than 100cm, serving as a grouting stop section without drilling.

3. The method for pre-reinforcement of anchor sections under broken surrounding rocks according to claim 1, characterized in that: In step S4, if the drilling is unqualified, the process returns to step S3 and re-drills.

4. The method for pre-reinforcement of anchor sections under broken surrounding rocks according to claim 1, characterized in that: In step S5, if the resistance is too great during the jacking process, it is necessary to exit and clean the hole again before continuing the jacking operation.

5. The method for pre-reinforcement of anchor sections under broken surrounding rocks according to claim 1, characterized in that: In step S5, 3m before entering the lower anchor section, the driving is advanced by 15°, and the driving is advanced by 4m to meet the overlap length. 1.8m before entering the lower anchor section, the driving is advanced by 23° at the expanded section angle of the arch top toward the lower anchor section, and the driving is advanced by 4m to meet the overlap length.

6. The method for pre-reinforcement of anchor sections under broken surrounding rocks according to claim 1, characterized in that: In step S5, the arch is used as the center line, and the other side is set at 15°, and the advance is 4m to meet the overlap length. When entering the anchor section, the second arch frame can be advanced, and the advance length is 3.5m.

7. The method for pre-reinforcement of anchor sections under broken surrounding rocks according to claim 1, characterized in that: In step S5, the construction of the anchoring section is equivalent to the construction of the auxiliary tunnel into the main tunnel. The spacing of the advance small guide tubes is adjusted according to the on-site construction, and it is appropriate to set them 1m above the arch foot of the upper step.

8. The method for pre-reinforcement of anchor sections under broken surrounding rocks according to claim 1, characterized in that: In step S7, during the grouting process, the changes in the grouting pressure and the grouting pump discharge volume should be observed at any time to analyze the grouting situation, prevent pipe blockage, paddle movement, and grout leakage, and keep grouting records to analyze the grouting effect.

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