Coal mine burnt rock stratum tunneling roadway exploration-dredging-injection-inspection collaborative treatment method

Abstract

The invention discloses a coal mine burnt rock stratum tunneling roadway exploration-dredging-injection-inspection collaborative treatment method, and belongs to the field of advanced treatment of roadway tunneling. Firstly, transient electromagnetic characteristics of stratums and water bodies are calibrated through borehole peeping, secondly, distribution of burnt rock stratums and water-containing bodies of the burnt rock stratums at the 10-meter boundary of a tunneling roadway horizontally mapped to the ground is accurately determined through a dynamic multi-transient electromagnetic method for boundary area encryption, and a three-dimensional geological map of a mapping area is constructed; then, an advanced treatment area is accurately determined according to a roadway tunneling plan, partial roadway multilayer surrounding type grouting hole groups and super-long long-term drainage holes of'one main branch, multiple branches and parallel branches' are formed based on a directional drilling technology, and finally, the grouting effect is detected in real time in the grouting process through ground transient electromagnetic detection, and grouting is completed. Grouting, tunneling and grouting inspection are synchronously carried out, and complete water reducing and reinforcing treatment of a burnt rock stratum system independent of a tunneling face is achieved.

Description

Technical Field

[0001] The invention belongs to the field of advanced management of tunnel excavation, and specifically is a coordinated management method of exploration-dredging-injection-inspection in tunnel excavation of burned rock strata in coal mines. Background Art

[0002] The burned rock strata formed by spontaneous combustion of coal fires in the marginal areas of sedimentary basins are characterized by developed fissures and broken rock strata, which are prone to enriching groundwater and threaten the safety of tunneling.

[0003] Currently, transient electromagnetic, remote sensing, drilling and other methods are mostly used to detect burned rock strata and water-rich areas. The above methods are difficult to accurately reflect the three-dimensional distribution of burned rock strata and their water bodies. The grouting curtain method of drilling straight holes on the excavation face is often used for treatment. This method is complicated to construct, and the drilling and grouting are mutually exclusive with the tunneling, which seriously slows down the progress of the project.

[0004] The prior art with publication number CN111456765A discloses a thin and thick shell support structure and construction method for extremely broken tunnels, the support structure includes a tunnel, the tunnel section is circular, and includes a thin shell and a thick shell, the thin shell includes a spliced ​​steel plate arranged along the inner wall of the tunnel surrounding rock, and there is a gap between the spliced ​​steel plate and the inner wall of the tunnel surrounding rock, the thick shell includes a filling seam body, an anchor rod and a grouting body, the filling seam body is filled in the gap, the anchor rod penetrates into the tunnel surrounding rock after passing through the spliced ​​steel plate, and the grouting body spreads along the broken cracks of the tunnel surrounding rock. It uses an anchoring device and a grouting area to effectively support the extremely broken tunnel surrounding rock, ensuring the overall stability of the tunnel surrounding rock, but it cannot be constructed for the more complex terrain and special geographical characteristics of the coal mine burnt rock strata. Summary of the invention

[0005] In view of the shortcomings of the existing technology, a method of coordinated exploration-drainage-injection-inspection management of coal mine burnt rock strata excavation tunnels is provided, which can achieve coordinated exploration and management, multiple uses of one hole, and water reduction and reinforcement management of burnt rock strata.

[0006] The technical solution of the present invention is as follows: the present invention discloses a method for coordinated management of exploration-drainage-injection-inspection in tunneling of burned rock strata in coal mines, the method comprising the following steps:

[0007] Step 1: According to the tunnel excavation plan, the excavation tunnel is horizontally radially expanded by 10 meters and mapped to the ground. A peep borehole is arranged on the surface of a presumed burnt rock distribution area in the mapping area, and a small area transient electromagnetic network is arranged in conjunction with the peep borehole. The peep borehole is used to obtain the location information of the underground rock layer and the burnt rock layer. The data results obtained by the small area transient electromagnetic network are used to draw a small area resistance distribution map, and the resistance characteristics of each rock layer are determined in combination with the peep borehole results.

[0008] Step 2: Transient electromagnetic measuring points are arranged at the surface boundary of the entire mapping area to conduct transient electromagnetic detection; a resistance distribution map of the regional boundary is drawn according to the data results of the transient electromagnetic detection, and the initial exploration boundary of the burned rock layer is drawn according to the resistance characteristics of the rock layer, and transient electromagnetic measuring points are added in the resistance distribution map of the boundary area, which represents the resistance mutation area of ​​the burned rock layer, so as to encrypt the transient electromagnetic network of the area, and conduct secondary fine transient electromagnetic detection again; based on the secondary fine detection data, network point coordinates, underground rock formation information and transient electromagnetic characteristics of the aquifer, a three-dimensional map of the distribution of strata and water bodies in the burned rock formation in the 10-meter boundary area of ​​the excavation tunnel is drawn, so as to determine the precise boundary of the burned rock formation;

[0009] Step 3: According to the location of the burnt rock layer and the distribution information of the water-bearing body, combined with the tunnel excavation plan that needs to pass through the burnt rock layer, determine that the advance treatment area of ​​the burnt rock layer that needs grouting treatment is within 5-10 meters outside the contour line of the pre-excavated tunnel section passing through the burnt rock layer;

[0010] Step 4. According to the advance treatment area of ​​the burnt rock stratum, determine the multi-layer surrounding directional drilling layout plan for the excavation tunnel passing through the burnt rock stratum, use directional drilling technology to form a main branch and multiple branches around the pre-developed excavation tunnel, and use a grouting method with parallel tunnels with branches. Drill a multi-layer surrounding grouting hole group and an ultra-long long-term drainage hole around the excavation tunnel passing through the burnt rock stratum. The lowest hole is used as a long-term drainage hole. Initially, all holes are drained. When only the long-term drainage hole is still discharging water, ground transient electromagnetic detection is used to check the grouting effect in real time during the grouting process, and grouting is used to carry out grouting. Finally, the grouting is completed, and grouting, excavation, and grouting inspection are carried out simultaneously to achieve complete water reduction and reinforcement treatment of the burnt rock stratum system.

[0011] Further, the specific process of step 6 is as follows:

[0012] Step 5.1, after excavating a part of the roadway, use the excavated part of the roadway to construct a directional long drainage hole and a grouting main hole along the roadway to be excavated and point to the burned rock stratum through which it passes, and construct multiple grouting branch holes on the grouting main hole, wherein the grouting main hole and the grouting branch holes are all around the pre-excavated roadway in the advanced treatment area of ​​the burned rock stratum, and are used to grout the burned rock stratum in the advanced treatment area of ​​the burned rock stratum;

[0013] Step 5.2: Deploy a high-density transient electromagnetic network with a grid spacing of no more than 10 meters over the advanced treatment area;

[0014] Step 5.3, use the long drainage hole to drain water, and after the water flow stabilizes, grouting is carried out into the pore and fissure space of the burnt rock formation from the grouting main hole. After the pressure of the grouting hole stabilizes, use the encrypted ultra-full-area transient electromagnetic network to conduct transient electromagnetic detection of the treatment area, and compare it with the initial transient electromagnetic detection results of the entire burnt rock distribution area in step 3, so as to obtain the information of the three-dimensional resistance change area, and determine the implementation of grouting according to the three-dimensional resistance change area. If the grouting area is smaller than the advanced treatment area of ​​the burnt rock formation, increase the grouting pressure and continue grouting. When the grouting area is larger than the advanced treatment area of ​​the burnt rock formation, stop grouting and seal the grouting holes to complete the treatment of the burnt rock formation in the coal mine.

[0015] Furthermore, transient electromagnetic detection uses ground transient electromagnetic detection technology without drilling.

[0016] Furthermore, the grouting radius of the grouting main holes and the grouting branch holes is obtained according to field practice, and the semi-enclosed grouting holes are cross-distributed between the contour line of the pre-excavation tunnel and the contour line of the advanced treatment area at a spacing of 1-2 times the grouting radius. The drilling starting point is located at the tunnel bottom plate and a side part; the grouting main holes and the grouting branch holes are arranged in a blood vessel-like spiral state to surround the super-pre-excavation tunnel.

[0017] Furthermore, when directional grouting main holes and grouting branch holes are constructed, the horizontal distance of the excavation surface from the burnt rock layer is greater than the designed tunnel excavation distance during the drilling-grouting-slurry solidification period, and the end point of the grouting branch hole is at the top of the burnt rock layer, and a geological casing with large holes is used to fix the hole;

[0018] Furthermore, the parallel tunnels of the grouting branch holes pass through the entire advanced treatment area section.

[0019] Compared with the prior art, the present invention has the following technical effects:

[0020] The present invention is based on the idea of ​​"coordination of governance and exploration - one hole for multiple uses - water reduction and reinforcement" during the excavation of burnt rock strata. The present invention uses the transient electromagnetic characteristics of borehole peek-a-bore to calibrate the strata and water bodies, and adopts the dynamic multiple transient electromagnetic method with boundary area encryption to accurately determine the distribution of the burnt rock strata and its water bodies, construct a regional three-dimensional geological map, and accurately determine the advance governance area according to the tunnel excavation plan. Based on the directional drilling technology, a multi-layer surrounded grouting hole group and an ultra-long long-term drainage hole for some tunnels with "one main branch and multiple branches, and the branches are parallel to the tunnels" are formed. Ground transient electromagnetic detection is used to check the grouting effect in real time during the grouting process and complete the grouting, simplifying the construction process, realizing the simultaneous grouting, excavation, and grouting inspection, realizing the complete water reduction and reinforcement governance of the burnt rock stratum system, ensuring the construction safety of the excavation tunnel, and greatly accelerating the progress of the tunnel excavation project. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1It is a schematic diagram of the transient electromagnetic layout of the borehole calibration in the exploration-drainage-injection-inspection coordinated management method for tunneling of burned rock strata in a coal mine according to an embodiment of the present invention;

[0022] Figure 2 It is a schematic diagram of regional dynamic multiple transient electromagnetic layout in an embodiment of the present invention;

[0023] Figure 3 It is a cross-sectional view of the advanced treatment area in the embodiment of the present invention;

[0024] Figure 4 Schematic diagram of directional drilling arrangement in an embodiment of the present invention.

[0025] In the figure: 1-peeping borehole, 2-transient electromagnetic measuring point, 3-distribution range of burned rock strata, 4-regional transient electromagnetic network, 5-transient electromagnetic measuring point, 6-precise boundary of burned rock strata, 7-preliminary exploration boundary of burned rock strata, 8-pre-excavation tunnel outline, 9-advanced treatment area outline, 10-excavation tunnel, 11-directional long drainage hole, 12-grouting main hole, 13-grouting branch hole. DETAILED DESCRIPTION

[0026] The embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0027] The present invention provides a "probe-drainage-injection-inspection" collaborative management method for coal mine burnt rock strata excavation tunnels. The method first uses borehole peeping to calibrate the transient electromagnetic characteristics of the strata and water bodies, and then uses a dynamic multiple transient electromagnetic method with boundary area encryption to accurately determine the distribution of the burnt rock strata and its water bodies, and constructs a regional three-dimensional geological map. Then, according to the tunnel excavation plan, the advanced management area is accurately determined, and based on the directional drilling technology, a multi-layer surrounded grouting hole group and ultra-long long-term drainage holes in some tunnels with "one main branch and multiple branches, and the branches are parallel to the tunnels" are formed. Finally, ground transient electromagnetic detection is used to check the grouting effect in real time during the grouting process and complete the grouting, so that grouting, excavation, and grouting inspection are carried out simultaneously, and the complete water reduction and reinforcement management of the burnt rock stratum system is realized.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1 and Figure 2 As shown, a "probe-drainage-injection-inspection" collaborative management method for tunneling in coal mine burnt rock strata includes the following steps:

[0030] Step 1, drilling a hole 1 in the estimated burned rock distribution area to the aquiclude below the burned rock layer distribution range 3, performing drilling observation to determine the rock layer distribution characteristics, water body layer and burned rock layer, using a non-drilling ground transient electromagnetic method, evenly arranging multiple transient electromagnetic measuring points 2 within a certain range on the ground around the borehole, jointly forming a transient electromagnetic network, and performing transient electromagnetic detection;

[0031] Step 2, comparing the water bodies and formation data of boreholes at different burial depths and transient electromagnetic results to determine the transient electromagnetic characteristics of the water bodies in the burned rock formations and each rock formation;

[0032] Step 3, a super-full-area transient electromagnetic network 4 is laid on the ground with a certain mesh density for the inferred burned rock distribution area, and transient electromagnetic detection is performed to draw a regional resistance distribution map, and the transient electromagnetic mesh density 5 at the resistance mutation point 7 is increased to perform secondary fine detection to determine the burned rock layer boundary 6, and a three-dimensional distribution map of the regional strata and the burned rock layer water body 3 is drawn according to the detection data, mesh point coordinates, and transient electromagnetic characteristics of the rock layer and aquifer;

[0033] Step 4, according to the distribution of the burned rock layer and the water-bearing body, combined with the tunnel excavation plan 8, determine that the burned rock layer advance treatment area 9 is within 5-10 meters outside the outline of the pre-excavated tunnel section passing through the burned rock layer;

[0034] Step 5. According to the advanced treatment area of ​​the burned rock strata, determine the layout plan of multi-layer surrounding directional drilling for some tunnels, where the grouting radius is obtained according to on-site practice, and the semi-enclosed grouting holes are cross-distributed between the contour line of the pre-excavated tunnel and the contour line of the advanced treatment area at a spacing of 1-2 times the grouting radius. The starting point of the drilling is located at the bottom plate and the side of the tunnel. The drilling adopts the layout method of "one main branch and multiple branches, and the branches are parallel to the tunnel". During the directional drilling construction, the horizontal distance of the excavation face from the burned rock stratum is greater than the designed tunnel excavation distance during the drilling-grouting-slurry solidification period. The end point of the drilling is at the top plate of the burned rock stratum. A geological casing with large holes is used to fix the hole, and the branch drilling holes parallel to the tunnel pass through the entire advanced treatment area. Figure 3 As shown, it includes a grouting trunk hole 12 and a grouting branch hole 13, and a tubular bifurcated structure is formed between the grouting trunk hole 12 and the grouting branch hole 13. The drilling structure composed of the grouting trunk hole 12 and the grouting branch hole 13 surrounds the super-pre-dig tunnel 10 in a spiral state, ensuring that the distance between the grouting trunk hole 12 and the grouting branch hole 13 and the super-pre-dig tunnel 10 is the same;

[0035] Step 6: deploy a high-density transient electromagnetic network with a grid spacing of no more than 10 meters over the advanced treatment area;

[0036] Step 7, implement directional drilling, open the drainage hole 11, wait for the water flow to stabilize, and then grout the crack space of the burnt rock stratum from the grouting hole 12. After the pressure of the grouting hole is stable, perform transient electromagnetic detection on the treatment area, and compare the detection results of step 1. Determine the grouting range according to the three-dimensional resistance change area. If the grouting area is smaller than the advanced treatment area of ​​the burnt rock stratum, increase the grouting pressure and continue grouting. When the grouting area is larger than the advanced treatment area of ​​the burnt rock stratum, stop grouting and seal the grouting hole. Figure 4 shown.

Claims

1. A method for coordinated management of exploration-dredging-injection-inspection in tunneling of coal mine burnt rock strata, characterized in that: The method comprises the following steps: Step 1: According to the tunnel excavation plan, the excavation tunnel is horizontally radially expanded by 10 meters and mapped to the ground. A peep borehole (1) is arranged on the surface of a presumed burnt rock distribution area in the mapping area, and a small area transient electromagnetic network (4) is arranged in conjunction with the peep borehole (1). The peep borehole (1) is used to obtain the location information of the underground rock layer and the burnt rock layer. The data results are obtained by using the small area transient electromagnetic network (4) to draw a small area resistance distribution map, and the resistance characteristics of each rock layer are determined in combination with the peep borehole results. Step 2: arranging transient electromagnetic measuring points at the surface boundary of the entire mapping area to conduct transient electromagnetic detection; drawing a resistance distribution map of the regional boundary based on the data results of the transient electromagnetic detection, drawing a preliminary exploration boundary of the burned rock layer based on the resistance characteristics of the rock layer (7), and adding transient electromagnetic measuring points (5) in the resistance distribution map of the boundary area representing the resistance mutation area of ​​the burned rock layer, thereby encrypting the transient electromagnetic network of the area, and conducting a secondary fine transient electromagnetic detection again; drawing a three-dimensional map of the stratum and water body distribution of the burned rock layer in the 10-meter boundary area of ​​the excavation tunnel based on the secondary fine detection data, the coordinates of the network points, the underground rock layer information and the transient electromagnetic characteristics of the aquifer, thereby determining the precise boundary of the burned rock layer (6); Step 3, according to the location of the burnt rock layer and the distribution information of the water-bearing body, combined with the tunnel excavation plan that needs to pass through the burnt rock layer, determine that the burnt rock layer advance treatment area (9) that needs grouting treatment is within 5-10 meters outside the outline of the pre-excavated tunnel (10) passing through the burnt rock layer; Step 4, according to the advance treatment area of ​​the burned rock stratum, determine the multi-layer surrounding directional drilling layout plan for the excavation tunnel (10) passing through the burned rock stratum, use directional drilling technology to form a main branch and multiple branches around the pre-developed excavation tunnel (10), and use a grouting method in which the branches are parallel to the tunnel. Multi-layer surrounding grouting hole groups and ultra-long long-term drainage holes are drilled around the excavation tunnel (10) passing through the burned rock stratum, among which the lowest hole is used as a long-term drainage hole. Initially, all holes are drained. When only the long-term drainage hole is still emitting water, ground transient electromagnetic detection is used to check the grouting effect in real time during the grouting process, and grouting is performed using the grouting hole group. Finally, grouting is completed, and grouting, excavation, and grouting inspection are carried out simultaneously, so as to realize complete water reduction and reinforcement treatment of the burned rock stratum system.

2. The method for coordinated management of exploration-dredging-injection-inspection in tunneling of coal mine burnt rock strata according to claim 1 is characterized in that: The specific process of step 6 is as follows: Step 5.1, after excavating a part of the tunnel, use the excavated part of the tunnel to construct a directional long drainage hole (11) and a grouting main hole (12) along the tunnel to be excavated and point to the burned rock layer it passes through, and construct a plurality of grouting branch holes (13) on the grouting main hole (12), wherein the grouting main hole (12) and the grouting branch holes (13) are all around the pre-excavated tunnel (8) in the area of ​​the burnt rock layer advance treatment area (9), and are used to grout the burnt rock layer in the burnt rock layer advance treatment area (9); Step 5.2: Deploy a high-density transient electromagnetic network with a grid spacing of no more than 10 meters over the advanced treatment area; Step 5.3, drain water through the long drainage hole (11), and after the water flow stabilizes, grouting is performed into the pore and fissure space of the burnt rock formation from the grouting main hole (12). After the pressure of the grouting hole stabilizes, the transient electromagnetic network of the encrypted ultra-full area is used to perform transient electromagnetic detection on the treatment area, and compared with the initial transient electromagnetic detection result of the entire burnt rock distribution area in step 3, the information of the three-dimensional resistance change area is obtained, and the implementation of grouting is determined according to the three-dimensional resistance change area. If the grouting area is smaller than the burnt rock formation advance treatment area (9), the grouting pressure is increased and grouting is continued. When the grouting area is larger than the burnt rock formation advance treatment area (9), the grouting is stopped and the grouting holes are sealed to complete the treatment of the burnt rock formation in the coal mine.

3. The method for coordinated management of exploration-dredging-injection-inspection in tunneling of coal mine burnt rock strata according to claim 1 is characterized in that: Transient electromagnetic detection uses ground transient electromagnetic detection technology without drilling.

4. The method for coordinated management of exploration-dredging-injection-inspection in tunneling of coal mine burnt rock strata according to claim 2 is characterized in that: The grouting radius of the main grouting holes (12) and the branch grouting holes (13) is obtained according to field practice. The semi-enclosed grouting holes are cross-distributed between the contour line of the pre-excavated tunnel and the contour line of the advanced treatment area (9) at intervals of 1-2 times the grouting radius. The drilling starting point is located at the tunnel bottom plate and a side part. The main grouting holes (12) and the branch grouting holes (13) are arranged in a blood vessel-like spiral state to surround the super pre-excavated tunnel (10).

5. The method for coordinated management of exploration-dredging-injection-inspection in tunneling of coal mine burnt rock strata according to claim 2 is characterized in that: When directional grouting the main hole (12) and the branch hole (13) is constructed, the horizontal distance of the excavation surface from the burnt rock layer is greater than the designed tunnel excavation distance during the drilling-grouting-slurry solidification period. The end point of the branch hole (13) is at the top of the burnt rock layer, and a geological casing with large holes is used to fix the hole.

6. The method for coordinated management of exploration-dredging-injection-inspection in tunneling of coal mine burnt rock strata according to claim 5 is characterized in that: The grouting branch holes (13) are parallel to the tunnel and pass through the entire advanced treatment area.

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