A comprehensive inspection method for the construction quality of inclined shaft and tunnel plugging using the mold bag method

Abstract

The present application discloses a comprehensive detection method for the construction quality of inclined shaft and tunnel plugging using the mold bag method, which comprehensively evaluates the plugging effect of the plugging section through a variety of detection means. The method includes six steps: first, coring is performed in the plugging section and the core height is measured to determine the plugging effect; then, water is pumped in an underwater environment to observe the water level drop to evaluate the plugging quality; water injection is performed in a waterless environment and the water level and leakage are measured to evaluate the plugging effect; the height, shape and contact condition of the plugging section are determined by drilling television; the flow rate change before and after water injection or grouting is observed by a flow rate tester to evaluate the plugging quality; and finally, cross-hole CT detection technology and tracer content detection method are used to perform cross-sectional scanning of the plugging section and evaluate the plugging effect. This method can comprehensively and accurately evaluate the construction quality of inclined shaft and tunnel plugging using the mold bag method, and has practical value and promotion significance.

Description

Technical Field

[0001] The present invention relates to the field of plugging tubular structures such as lanes, inclined shafts, tunnels, etc., and specifically relates to a comprehensive detection method for the construction quality of plugging inclined shafts and lanes using a mold bag method. Background Art

[0002] In patent application CN114658480, entitled "Device and method for plugging inclined shafts in goaf tunnels by mold bag grouting", a device and method for plugging inclined shafts in goaf tunnels by mold bag grouting is disclosed. The device includes a mold bag, a grouting pipe and a protective component. The public document details the principle of the method for plugging inclined shafts and tunnels in goafs by the mold bag method. The mold bag method refers to lowering the processed mold bag and the grouting pipe structure into the inclined shaft tunnel through surface drilling, and filling the mold bag completely by grouting to form a plugging structure. The mold bag method for grouting abandoned inclined shafts and tunnels in goafs has a good development prospect. The emergence of new plugging methods is accompanied by how to detect its plugging effect. If the detection is not timely or inaccurate, it will cause the grouting liquid to overflow in subsequent construction, affecting subsequent construction and causing waste. Based on this, the present invention proposes a comprehensive detection method for the construction quality of plugging inclined shafts and tunnels by the mold bag method. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the above technical defects and provide a comprehensive detection method for the construction quality of inclined shaft and tunnel plugging using the mold bag method. The comprehensive quality detection is performed using the coring height, the change in water level of the measuring hole, the internal imaging of the measuring hole, the change in flow velocity of the measuring hole, the cross-sectional scanning imaging, and the tracer content. The method specifically includes the following steps:

[0004] Step S1: After the grouting material in the mold bag has finally solidified to form a plugging section, drilling is performed to obtain a first measuring hole, and coring is performed on the plugging section to determine the height of the coring knot, thereby judging the plugging effect of the plugging section; when the height of the coring knot is lower than the height of the inclined shaft roadway, it indicates that the plugging effect of the mold bag method is poor; when the height of the coring knot is equal to the height of the inclined shaft roadway, it proves that the plugging effect of the mold bag method meets the plugging requirements;

[0005] Step S2: For a water-filled environment, a second measuring hole is drilled below the plugging section to obtain a second measuring hole, and a submersible pump is used to pump water in the inclined shaft tunnel at the bottom of the second measuring hole; when the water level drops significantly, it indicates that the mold bag has a good plugging effect, and the plugging quality of this section can be judged to be qualified; when the water level drops slightly or does not drop at all, the plugging effect of the mold bag cannot be judged because it is not possible to determine whether there is a water channel between the inclined shaft tunnel below the mold bag plugging structure and the stratum; for a waterless environment, a third measuring hole is drilled above the plugging section to obtain a third measuring hole, and the initial water level in the third measuring hole is first tested and recorded, and then water is injected into the third measuring hole. After a period of water injection, the plugging effect is comprehensively evaluated by testing the water level and leakage amount in the third measuring hole;

[0006] Step S3: A borehole camera is lowered into the first measuring hole or the second measuring hole. The built-in lighting system of the borehole camera can be used to preliminarily determine the height, shape, and contact status of the blocked section with the inclined shaft tunnel.

[0007] Step S4: Place the flow rate tester into the inclined shaft through the second measuring hole, perform water injection or grouting in the third measuring hole, and observe and record the flow rate change of the flow rate tester before and after the water injection or grouting; if there is no difference or a very small difference in the flow rate before and after the water injection or grouting, it indicates that the mold bag grouting and plugging quality is qualified; if the flow rate increases significantly after the water injection or grouting, and a water flow is obviously formed, it indicates that the mold bag grouting and plugging quality is unqualified;

[0008] Step S5: When the detection methods of steps S1 to S4 above are unable to provide a satisfactory determination, fourth measuring holes are drilled at the left-right symmetrical position of the blocked section and at a certain distance from the outer wall of the inclined shaft. A cross-hole CT detection technology is used in the fourth measuring holes to perform a cross-sectional scan of the blocked section to determine the shape and size of the blocked section.

[0009] Step S6: inject a tracer into the third measuring hole, and detect the tracer content in the second measuring hole below the plugging section to determine the plugging effect of the mold bag.

[0010] Furthermore, when there are ambiguous detection and evaluation standards in the detection methods of the above-mentioned steps S1 to S6, the grouting method is used for combined sealing, and the sealing quality of the combination of the mold bag and grouting is then evaluated; when the quality of the mold bag grouting sealing is determined to be qualified after the above-mentioned steps S1 to S6, the inclined shaft tunnel section is sealed. Cement fly ash slurry is usually used to seal the inclined shaft tunnel section. Based on the principle that different slurries of fly ash raw materials have different strengths and colors, fly ash with larger color differences is used for grouting sealing in the grouting sealing section and the adjacent sections. After the work, the differences in the color and strength of the grouting sealing section and the adjacent sections are detected to verify the accuracy of the detection methods of steps S1 to S6 again.

[0011] Furthermore, there are ambiguous situations in the detection method of steps S1 to S6 as follows:

[0012] In step S1, the height of the coring knot is close to the height of the inclined shaft tunnel; in step S2, the water replenishment speed cannot be judged or there is a water guide channel in the inclined shaft tunnel below the mold bag sealing structure; in step S4, there is a difference in water flow velocity before and after water injection or grouting, but the difference is small; in step S5, it is estimated that the shape and volume of the mold bag sealing structure are slightly different from the cross-section of the inclined shaft tunnel, but the difference is not large.

[0013] Furthermore, the construction method of the grouting plugging section specifically includes the following steps:

[0014] A first borehole and a second borehole are formed in the grouting plugging section, grouting material is injected into the third measuring hole, and the grouting is stopped after a setting zone is formed;

[0015] Secondary grouting is carried out in the first borehole. At this time, the second borehole serves as a drainage hole during the secondary grouting. In addition, the second borehole serves as an overflow hole for judging the grouting strength standard of the plugging section of the inclined well.

[0016] Once the slurry solidifies and the water is extracted from the plugging section of the inclined well, the pumping operation is carried out again, and the second borehole is used as the pumping hole;

[0017] Finally, after the pumping operation is completed, the third grouting is carried out, and the second borehole is used as the grouting hole.

[0018] Furthermore, during the initial grouting process, the third measuring hole is injected with a quick-setting, poorly fluid, paste-like grouting material. The secondary grouting slurry generally uses a cement fly ash slurry with better fluidity. The third grouting slurry uses a slightly expansive grouting material.

[0019] The advantages of the present invention over the prior art are: the present invention provides a comprehensive detection method for the construction quality of inclined shafts and tunnels using the mold bag method, provides corresponding detection methods for water-filled and water-free environments of inclined shafts and tunnels, and comprehensively evaluates the quality of mold bag blocking through multiple groups of detection methods. The emergence of the present invention forms a closed loop for the technology of blocking inclined shafts and tunnels using the mold bag method of grouting, which has played a boosting role in the promotion and application of this new method. The mold bag grouting method for blocking inclined shafts and tunnels, combined with its detection technology, solves the difficult problems of blocking and treating goafs, tunnels and inclined shafts with large internal water content and strong connectivity, saves a large amount of grouting materials, improves the blocking effect, reduces engineering costs, and brings good environmental and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a cross-sectional view of an inclined shaft tunnel sealed by grouting using the bag method.

[0021] Figure 2 This is a top view of the inclined shaft tunnel sealed by grouting using the bag method.

[0022] Figure 3 It is a schematic diagram of the cross-section of grouting to seal the inclined shaft tunnel construction.

[0023] Figure 4 It is the construction flow chart of grouting to seal inclined shaft tunnels.

[0024] Figure numerals: 1, plugging section, 2, grouting plugging section, 3, coagulation zone, 3-1, first measuring hole, 3-2, second measuring hole, 3-3, third measuring hole, 3-4, second borehole, 3-5, fourth measuring hole, 3-6, first borehole. DETAILED DESCRIPTION

[0025] The following is a complete and clear introduction to the technical solutions in the embodiments of the present invention. The described examples are only some examples of the present invention. Other embodiments obtained by ordinary technicians in this field without making creative work are all within the scope of protection of the present invention.

[0026] Combined with attachment Figure 1 -Attached Figure 4 A comprehensive quality inspection method for the construction of inclined shafts and tunnels plugged with a mold bag method is provided. The method utilizes the coring height, the change in water level in the measuring hole, the internal imaging of the measuring hole, the change in flow velocity in the measuring hole, the cross-sectional scanning imaging, and the tracer content to conduct a comprehensive quality inspection. The method specifically includes the following steps:

[0027] Step S1: After the grouting material in the mold bag has finally set to form a plugging section 1, drilling is performed to obtain a first measurement hole 3-1. Coring is then performed on the plugging section 1 to determine the height of the coring knot, thereby assessing the plugging effectiveness of the plugging section 1. If the coring knot height is lower than the height of the inclined shaft, the mold bag method is ineffective. If the coring knot height is equal to the height of the inclined shaft, the mold bag method meets the plugging requirements, but the effectiveness of the mold bag knot on the sidewall of the inclined shaft cannot be verified. This detection sub-method is low-cost, simple, efficient, and accurate, making it a crucial indicator and a mandatory test.

[0028] Step S2: For a water-filled environment, a second measuring hole 3-2 is obtained by drilling below the plugging section 1, and a submersible pump is used to pump water in the inclined shaft tunnel at the bottom of the second measuring hole 3-2; when the water level drops significantly, it indicates that the mold bag has a good plugging effect, and the plugging quality of this section can be judged to be qualified; when the water level does not drop significantly or does not drop at all, the plugging effect of the mold bag cannot be judged, because it is not possible to determine whether there is a water guide channel between the inclined shaft tunnel below the mold bag plugging structure and the stratum; for a water-free environment, a third measuring hole 3-3 is obtained by drilling above the plugging section 1, and the initial water level in the third measuring hole 3-3 is first tested and recorded, and then water is injected into the third measuring hole 3-3. After a period of water injection, the plugging effect is comprehensively evaluated by testing the water level and leakage amount in the third measuring hole 3-3; this method of judging the quality of mold bag grouting plugging based on water level change has the advantages of low cost, simple construction, and obvious judgment indicators;

[0029] Step S3: By lowering a borehole camera into the first measuring hole 3-1 or the second measuring hole 3-2, the height, shape, and contact status of the plugged section 1 with the inclined shaft tunnel can be preliminarily determined using the built-in lighting system of the borehole camera. This seed detection method relies heavily on the turbidity of the water environment in the inclined shaft tunnel in a water-filled environment, and has significant limitations in its implementation. However, this method is more applicable in the absence of groundwater interference and has the advantages of being fast, simple, easy to use, and low-cost.

[0030] Step S4: Place a flow rate tester into the inclined shaft through the second measuring hole 3-2, perform water injection or grouting in the third measuring hole 3-3, and observe and record the flow rate change of the flow rate tester before and after the water injection or grouting; if there is no difference or a very small difference in the flow rate before and after the water injection or grouting, it indicates that the mold bag grouting and plugging quality is qualified; if the flow rate increases significantly after the water injection or grouting, and a water flow is obviously formed, it indicates that the mold bag grouting and plugging quality is unqualified;

[0031] Step S5: If the detection methods in steps S1 through S4 above fail to provide a satisfactory result, fourth measuring holes 3-5 are drilled at symmetrical locations around the plugged section 1 and at a certain distance from the outer wall of the inclined shaft. Cross-hole CT scanning of the plugged section 1 is performed within these fourth measuring holes 3-5 to determine its shape and size. The quality of the mold bag plugging can then be comprehensively evaluated using the aforementioned methods. This detection method is relatively costly, but due to the smaller cross-hole spacing, CT detection technology is more accurate.

[0032] Step S6: inject a tracer into the third measuring hole 3-3, and detect the tracer content in the second measuring hole 3-2 below the plugging section 1 to determine the plugging effect of the mold bag.

[0033] In one embodiment, when there are ambiguous detection and evaluation criteria in the detection methods of steps S1 to S6 above, grouting is used for combined plugging, and the plugging quality of the combination of the mold bag and grouting is then evaluated. The ambiguous situations in the detection method are as follows: in step S1, the height of the coring knot is close to the height of the inclined shaft; in step S2, the water replenishment rate cannot be evaluated or there is a water guide channel in the inclined shaft below the mold bag plugging structure; in step S4, there is a difference in water flow rate before and after water injection or grouting, but the difference is small; in step S5, there is a slight difference between the estimated shape and volume of the mold bag plugging structure and the cross-section of the inclined shaft, but the difference is not large, etc.

[0034] When the quality of the mold bag grouting and plugging is determined to be qualified after the above-mentioned steps S1 to S6, the inclined shaft tunnel section is sealed. Cement fly ash slurry is usually used to plug the inclined shaft tunnel section. Based on the principle that different slurries of fly ash raw materials have different strengths and colors, fly ash with large color differences is used for grouting and plugging in section 2 and adjacent sections. After the work, the differences in color and strength of the grouting and plugging sections 2 and adjacent sections are tested to verify the accuracy of the detection methods of steps S1 to S6 again.

[0035] In one embodiment, the construction method of the grouting plugging section 2 specifically includes the following steps:

[0036] The first borehole 3-6 and the second borehole 3-4 are formed in the grouting plugging section 2, and the grouting material is injected into the third measuring hole 3-3. After the coagulation zone 3 is formed, the grouting is stopped. The first borehole 3-6 is grouted twice. The second grouting slurry generally uses cement fly ash slurry with good fluidity. At this time, the second borehole 3-4 is used as a drainage hole during the second grouting. Secondly, the second borehole 3-4 is used as an overflow hole to judge the grouting solidity standard of the inclined well plugging section. Once again, after the slurry solidifies and the water is extracted from the inclined well plugging section, pumping is performed. At this time, the second borehole 3-4 is used as a pumping hole. Finally, after the pumping operation is completed, the third grouting is performed, which can also be called grouting. The third grouting slurry uses a slightly expansive grouting material. At this time, the second borehole 3-4 is used as a grouting hole. In summary, the three grouting operations and related construction processes comprehensively ensure the construction quality of the inclined well plugging section.

[0037] The above is a detailed introduction to the construction quality method of sealing inclined shaft tunnels using the mold bag method provided by the implementation of the present invention. For those skilled in the art, the present invention can have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A comprehensive detection method for the construction quality of inclined shaft and tunnel plugging using a mold bag method, characterized in that: Comprehensive quality inspection is performed using the coring height, measurement of hole water level change, measurement hole internal imaging, measurement hole flow velocity change, cross-sectional scanning imaging, and tracer content. The specific steps include: Step S1, after the grouting material in the mold bag is finally solidified to form a plugging section (1), drilling construction is carried out to obtain a first measuring hole (3-1), and coring operation is carried out on the plugging section (1), and the height of the coring knot is determined to judge the plugging effect of the plugging section (1); when the height of the coring knot is lower than the height of the inclined shaft roadway, it indicates that the plugging effect of the mold bag method is not good; when the height of the coring knot is equal to the height of the inclined shaft roadway, it proves that the plugging effect of the mold bag method meets the plugging requirements; Step S2, for a water-filled environment, drilling construction is performed below the plugging section (1) to obtain a second measuring hole (3-2), and a submersible pump is used to perform water pumping operations in the inclined shaft tunnel at the bottom of the second measuring hole (3-2); when the water level drops significantly, it indicates that the mold bag plugging effect is good, and the plugging quality of this section can be judged to be qualified; when the water level drops slightly or does not drop at all, the mold bag plugging effect cannot be judged, because it is not possible to determine whether there is a water-conducting channel between the inclined shaft tunnel below the mold bag plugging structure and the stratum; for a water-free environment, drilling construction is performed above the plugging section (1) to obtain a third measuring hole (3-3), firstly, the initial water level in the third measuring hole (3-3) is tested and recorded, and then water is injected into the third measuring hole (3-3). After a period of water injection, the plugging effect is comprehensively evaluated by testing the water level and leakage amount in the third measuring hole (3-3); Step S3: by lowering a borehole television into the first measuring hole (3-1) or the second measuring hole (3-2), the height, shape and contact condition of the blocking section (1) with the inclined shaft tunnel can be preliminarily determined by using the built-in lighting system of the borehole television; Step S4, placing a flow rate tester into the inclined shaft through the second measuring hole (3-2), performing water injection or grouting in the third measuring hole (3-3), observing and recording the flow rate change of the flow rate tester before and after the water injection or grouting; if there is no difference in the flow rate before and after the water injection or grouting or the difference is extremely small, it indicates that the mold bag grouting and plugging quality is qualified; if the flow rate increases significantly after the water injection or grouting and a water flow is obviously formed, it indicates that the mold bag grouting and plugging quality is unqualified; Step S5: When the detection methods of the above steps S1 to S4 are unable to make a good judgment, fourth measuring holes (3-5) are drilled at the left and right symmetrical positions of the blocking section (1) and at a certain distance from the outer wall of the inclined shaft tunnel, and a cross-hole CT detection technology is used in the fourth measuring holes (3-5) to perform a cross-sectional scan of the blocking section (1) to determine the shape and size of the blocking section (1); Step S6: inject a tracer into the third measuring hole (3-3), and detect the tracer content in the second measuring hole (3-2) below the plugging section (1) to determine the plugging effect of the mold bag.

2. A comprehensive detection method for the construction quality of inclined shaft and tunnel plugging using a mold bag method according to claim 1, characterized in that: When there are ambiguous detection and evaluation standards in the detection methods of the above steps S1 to S6, the grouting method is used for combined plugging, and the plugging quality after the combination of the mold bag and the grouting is evaluated again; when the mold bag grouting plugging quality is determined to be qualified after the above steps S1 to S6 are detected, the inclined shaft tunnel section is plugged, and cement fly ash slurry is usually used to plug the inclined shaft tunnel section. Based on the principle that different slurries of fly ash raw materials have different strengths and colors, when grouting the plugging section (2) and the adjacent sections, fly ash with a large color difference is used for grouting plugging. After the work, the color and strength differences of the grouting plugging section (2) and the adjacent sections are detected to verify the accuracy of the detection methods of steps S1 to S6 again; The following are the ambiguous situations in the detection method of steps S1 to S6: In step S1, the height of the coring knot is close to the height of the inclined shaft tunnel; in step S2, the water replenishment speed cannot be judged or there is a water guide channel in the inclined shaft tunnel below the mold bag sealing structure; in step S4, there is a difference in water flow velocity before and after water injection or grouting, but the difference is small; in step S5, it is estimated that the shape and volume of the mold bag sealing structure are slightly different from the cross-section of the inclined shaft tunnel, but the difference is not large.

3. A comprehensive detection method for the construction quality of inclined shaft and tunnel plugging using a mold bag method according to claim 2, characterized in that: The construction method of the grouting plugging section (2) specifically comprises the following steps: A first borehole (3-6) and a second borehole (3-4) are formed in the grouting plugging section (2), grouting material is injected into the third measuring hole (3-3), and the grouting is stopped after a coagulation zone (3) is formed; Secondary grouting is performed in the first borehole (3-6), and the second borehole (3-4) is used as a drainage hole during the secondary grouting. The second borehole (3-4) is also used as an overflow hole for judging the grouting strength standard of the plugging section of the inclined well. Once the slurry solidifies and the water is extracted from the plugging section of the inclined well, the pumping operation is carried out again. At this time, the second borehole (3-4) is used as the pumping hole; Finally, after the pumping operation is completed, the third grouting is carried out, and the second borehole (3-4) is used as the grouting hole.

4. A comprehensive detection method for the construction quality of inclined shaft and tunnel plugging using a mold bag method according to claim 3, characterized in that: During the initial grouting process, the third measuring hole (3-3) is injected with a quick-setting, poorly fluid, paste-like grouting material. The secondary grouting slurry generally uses a cement fly ash slurry with better fluidity. The third grouting slurry uses a slightly expansive grouting material.

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