A process for treating seepage water from the roof of a roadway

Abstract

This invention provides a method for treating seepage water from the roof of a roadway, belonging to the field of mine safety production technology. The process includes: collecting hydrogeological data, conducting three-dimensional surveying of the roadway, and logging the roadway's engineering geology and hydrogeology; determining the construction location of water guide holes based on the logging results, constructing multiple rows of water guide holes arranged in a diamond pattern, installing orifice pipes and main water guide pipes, and collecting and discharging the seepage water to the roadway drainage ditch, etc. This invention reduces seepage pressure and the phreatic line within the roof rock mass through active diversion, concentrating and channeling dispersed seepage water, significantly improving the roadway working environment, mitigating the softening effect of groundwater on the surrounding rock, and significantly improving the long-term stability of the roadway's surrounding rock.

Description

Technical Field

[0001] This invention belongs to the field of mine safety production technology, specifically relating to a method and system for treating seepage water in roadway roof. Background Technology

[0002] In the development of non-coal and metal / non-metal mines, tunnel construction and long-term maintenance often face the severe challenge of groundwater seepage. When tunnels traverse areas with complex hydrogeological conditions and well-developed fault structures, roof seepage is particularly prominent. This scattered, large-scale roof seepage leads to slippery conditions within the tunnel, severely deteriorating the working environment and affecting normal production. More importantly, seepage continuously softens the surrounding rock of the tunnel roof, especially phyllite and mudstone, which are easily softened by water. This significantly reduces the bearing capacity of the surrounding rock, posing a serious threat to the long-term stability of the tunnel's surrounding rock and easily triggering safety accidents such as roof collapse, spalling, or even large-scale landslides.

[0003] To address the above problems, existing technologies mainly employ the following methods: ① Grouting and sealing, which involves injecting cement grout or chemical grout into rock fissures to block seepage channels. However, for fractured rock masses with well-developed fissures, the grout diffusion range is difficult to control, resulting in limited sealing effectiveness. Furthermore, the sealing body is prone to failure again under water pressure, leading to recurrence of seepage. ② Simply setting up drainage ditches or water pipes. These methods can only treat water that has already dripped onto the tunnel floor. They cannot effectively collect and guide water that has dripped onto the roof over a large area, which leads to a long-term high-humidity environment in the tunnel and fails to fundamentally solve the problem of water softening the surrounding rock.

[0004] Therefore, there is an urgent need for a treatment method that can effectively collect and divert dispersed seepage water from the roof of the roadway, and actively reduce groundwater pressure and phreatic line height in the surrounding rock, so as to fundamentally improve the working environment of the roadway and enhance the long-term stability of the surrounding rock. Summary of the Invention

[0005] This invention addresses the problem of dispersed seepage from the roof of tunnels under complex geological conditions, which leads to softening of the surrounding rock and deterioration of the working environment, by providing a process for treating seepage water from the roof of tunnels.

[0006] The technical solution adopted in this invention is as follows: A process for treating seepage water from the roof of a roadway includes the following steps: Data preparation steps: Collect and analyze hydrogeological data of the mining area to determine the associated area between the surface recharge source and the roadway roof; specifically, collect topographic and geological maps of the mining area, hydrogeological maps of the mine, and relevant data on geological structures, sort out the engineering geological and hydrogeological conditions of the roadway construction area, understand the source, seepage path and flow direction of the seepage water in the roadway, and draw the seepage curve at the bottom of the riverbed.

[0007] The tunnel measurement steps are as follows: 3D measurement of the tunnel is carried out to establish a 3D model of the tunnel; specifically, a total station or 3D laser scanner is used to accurately measure the target tunnel to obtain the required data such as tunnel cross-sectional dimensions, direction, and elevation, and a 3D model of the tunnel is drawn, and the required information such as the tunnel centerline, roof outline, and floor elevation are marked.

[0008] The tunnel logging process involves: First, performing engineering geological and hydrogeological logging of the tunnel to identify seepage areas and pathways, and creating a logging map. Specifically, detailed logging is conducted along the tunnel's direction, recording lithological change boundaries, fault locations and attitudes, and the density and direction of joint and fracture development. The location, extent, and volume of roof seepage points, sprinkling areas, and inrush points are marked, along with the water turbidity. The guiding and controlling effects of faults and joints on groundwater are analyzed to determine the main seepage channels. Then, the logging information is overlaid on the tunnel's 3D map to create a clear engineering geological and hydrogeological logging map that shows lithological zoning, structural distribution, and the extent of seepage areas.

[0009] Steps for determining the location of the water guide hole: Based on the logging map, superimpose the projection areas of the seepage area and the related area on the roadway roof to determine the construction location of the water guide hole; specifically, based on the comprehensive analysis of the logging map, determine the section with the most severe seepage and the largest water volume on the roof as the core treatment area, and mark the corresponding roadway roof range on the three-dimensional map of the roadway in conjunction with the projection position of the bottom of the surface riverbed or the main recharge source. Prioritize the overlapping area of ​​the above two as the starting point for the construction of the water guide hole.

[0010] Construction steps for water guide holes: At the construction location of the water guide holes, construct multiple rows of water guide holes along the roof of the roadway; specifically, the water guide holes are arranged in a diamond pattern, symmetrically extending from the center line of the roof of the roadway to both sides, and the number of water guide holes in each row is determined according to the width of the roadway; among them, the parameters such as the diameter, depth, row spacing, radial center height, forward inclination angle and side hole angle of the water guide holes are all set according to the on-site hydrogeological conditions, and a hydraulic rock drilling rig is used for drilling, and the advance pressure during the opening and normal rock drilling stages is strictly controlled.

[0011] Water diversion system installation steps: Install orifice pipes at the opening of each water diversion hole, and install a pipe network to collect and drain the seepage water to the roadway drainage ditch; specifically, install orifice pipes at the opening of each water diversion hole, ensuring that the orifice pipes are in tight contact with the hole wall; below the orifice pipes, lay an arc-shaped main water diversion pipe along the cross-section of the roadway; reserve T-type interfaces on the main water diversion pipe corresponding to the position of each orifice pipe, and insert the lower end of the orifice pipe into the corresponding T-type interface; use expansion bolts and pipe clamps to fix the main water diversion pipe to the roadway arm, and connect the end of the main water diversion pipe to the drainage ditches on both sides of the roadway, so that the seepage water flows by gravity along the pipe to the drainage ditch for unified discharge.

[0012] In the above process, as a preferred technical solution, the water guide holes are arranged in a diamond pattern, and the depth of each row of water guide holes gradually decreases from the center line of the roof in the roadway to both sides; and the radial center of the water guide holes is located at the center line of the roadway; specifically, the water guide holes include intermediate water guide holes and lateral water guide holes, and the depth of the intermediate water guide holes is greater than the depth of the lateral water guide holes.

[0013] In the above process, as a preferred technical solution, a hydraulic trolley is used to construct the water guide hole. The propulsion pressure at the time of drilling is the first propulsion pressure. After the drill bit enters the rock to a predetermined depth, the propulsion pressure is adjusted to the second propulsion pressure for rock drilling. The second propulsion pressure is greater than the first propulsion pressure. When constructing the water guide hole, the centerline of the hydraulic trolley is aligned with the centerline of the roadway, and the jack bases on both sides of the trolley are used as reference points for relocation and positioning to control the deviation between the relocation position and the design position.

[0014] The beneficial effects of this invention are as follows: On the one hand, by constructing multiple rows of medium-deep water guide holes, this invention actively reduces the seepage pressure and wetting line height in the roof rock mass of the roadway, transforming the dispersed fissure water in the fractured roof rock mass from disordered seepage to orderly flow, thereby achieving centralized and efficient collection and orderly discharge of roof seepage water, significantly improving the working environment in the roadway. On the other hand, by actively draining and reducing pressure, this invention effectively mitigates the softening, mudification, and scouring effects of groundwater on fractured surrounding rock and water-softened rock strata, thereby curbing the deterioration of surrounding rock strength from the source. This significantly improves the long-term stability of the roadway roof, reduces safety risks such as roof collapse and slab fall, and ensures safe production in the mine. This invention is highly targeted and efficient in construction, and is especially suitable for roadway seepage control under complex hydrogeological conditions where surface water replenishment and tectonic fracture zones are developed. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the process flow of the present invention; Figure 2 This is a schematic diagram of the water guide hole structure in this invention; Figure 3 This is a schematic diagram of the tunnel water diversion system in this invention; Figure 4 This is a schematic diagram of the tunnel drainage system in this invention.

[0016] In the diagram: 1-seepage tunnel, 2-drainage ditches on both sides of the tunnel, 3-water guide hole, 4-fixture, 5-orifice pipe, 6-T-type interface, 7-main water guide pipe. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] This embodiment provides a process for treating seepage water from the roof of a roadway. Taking a ventilation roadway in a metal mine affected by seepage from the bottom of a riverbed as the engineering background, the roadway roof is mainly composed of phyllite with well-developed fault fracture zones. After construction, large-scale, dispersed seepage occurred, with the water-soaked area accounting for more than 60% of the total roof area. The maximum seepage rate at a single point reached 0.5 cubic meters per hour, seriously threatening the stability of the roadway and the safety of workers. This embodiment includes the following steps: First, data preparation and on-site investigation were carried out, including collecting regional hydrogeological maps, topographic geological maps, and engineering geological survey reports of the surrounding tunnels in the mining area. The focus was on analyzing the hydraulic connection between surface rivers, alluvial layers, and the tunnels below. Based on borehole water level data and pumping test results, a groundwater seepage curve at the bottom of the riverbed was drawn.

[0019] like Figure 1 As shown in the diagram, the seepage curve indicates that the groundwater level in the gravel layer at the bottom of the riverbed is about 15 meters higher than the elevation of the tunnel roof, forming a stable pressure head. It is determined that the main channel for surface water to replenish the deep tunnel is downward seepage along the fault fracture zone, with the affected area covering a section of about 200 meters in the middle of the entire ventilation tunnel. It is clear that the seepage water in this ventilation tunnel mainly comes from the surface water seeping down from the gravel layer in the riverbed, and the seepage flow rate is positively correlated with the upstream river water level.

[0020] Secondly, precise measurement and 3D modeling of the tunnel were carried out. A Leica total station was used to accurately measure the target tunnel, with the measuring point spacing set at 2 meters, and the spacing increased to 0.5 meters in fault zones and areas with severe water seepage. Data such as tunnel cross-sectional dimensions, orientation, floor and roof elevations were obtained. Specifically, the tunnel cross-section is a three-centered arch shape with a net width of 4.5 meters and a net height of 3.8 meters.

[0021] Based on the measurement data, a three-dimensional model of the tunnel was drawn using the mining 3D modeling software Surpac. Key geometric information such as the tunnel's central axis, roof outline, and floor elevation were clearly marked in the model. The model coordinate system was aligned with the mining area's geodetic coordinate system to provide an accurate spatial reference for subsequent borehole design. At the same time, the known fault locations and attitudes were marked in the 3D model.

[0022] Then, detailed engineering geological and hydrogeological logging was carried out; at the tunnel site, meticulous logging work was carried out along the tunnel direction, with the logging length covering the entire seepage section, totaling 200 meters.

[0023] The boundary line recording lithological changes: the top lithology is mainly phyllite, interbedded with thin layers of metamorphic sandstone. The phyllite is gray to grayish-green, with well-developed foliation, and softens when squeezed by hand after contact with water.

[0024] Record the specific location and attitude of the fault: A normal fault was exposed at a certain point in the tunnel. The fault strikes 30 degrees north of east and dips southeast at an angle of 65 degrees. The fault fracture band is about 1.2 meters wide and is filled with fault breccia and mylonite.

[0025] Joint density: Near the fault zone, the joint density reaches 15 to 20 joints per meter, and the joint surfaces are mostly open and filled with clay and iron-manganese films.

[0026] The exact location, size, and estimated volume of each seepage point, water-spraying section, and gushing point on the top slab should be clearly marked.

[0027] In some sections, the roof slab experienced continuous water spray, covering 90% of the roof slab area in that section. Using measuring cylinders and stopwatches, the water flow rate at one single point reached 0.8 cubic meters per hour.

[0028] Record the turbidity of the water: the water is relatively clear at first, but gradually becomes turbid, containing fine sand and rock fragments, indicating that the seepage channels are well connected.

[0029] Analysis of the water-conducting effect of fault fracture zones and dense joint and fissure zones on groundwater: It was determined that the main seepage channels are partial fault sections and their derived fissure networks. Surface water moves downward along the fault zone and seeps out in a dispersed manner at the roadway roof due to stress unloading.

[0030] All information was integrated, and a geological and hydrogeological logging map of the tunnel was drawn based on the three-dimensional model of the tunnel. The map was printed at a scale of 1:200 and clearly showed the lithological zoning, structural distribution, and the range of the three main seepage zones, of which Zone A was a severely seepage zone with a length of 40 meters.

[0031] Next, the construction location of the water diversion holes was determined. Section A, marked on the tunnel logging map as having the most severe roof seepage and the largest water volume, was selected as the core treatment target area. At the same time, the projection area of ​​the bottom of the surface riverbed obtained from the previous data analysis was marked on the 3D tunnel map to indicate its corresponding roof range. The projection area of ​​the bottom of the riverbed exactly covers part of the tunnel mileage. The above-mentioned severely seeping area was spatially superimposed with the projection area of ​​the surface recharge source, and the section with the highest degree of overlap was selected as the priority to determine the construction starting point of the first row of water diversion holes. This can directly intercept the main groundwater flow from the fault zone and cut off the main channel for surface water seepage into the tunnel.

[0032] Next, as Figure 2 As shown, the design and construction of the water guide hole are carried out.

[0033] The water guide holes 3 are arranged in a diamond pattern. The boreholes are drilled symmetrically from the center line of the roof plate in the roadway to both sides. The roadway is 4.5 meters wide, and 14 water guide holes 3 are arranged in each row. The radial center of the boreholes is located on the center line of the roadway, 1.6 meters above the floor plate. This height is convenient for the operation of the hydraulic trolley.

[0034] The forward inclination angle of the water guide hole 3 is designed to be 87 degrees, meaning that the borehole is basically vertical upward, but tilted 3 degrees towards the inside of the roadway. This allows the bottom of the hole to enter the upstream of the seepage zone more accurately. The side angle of the outermost water guide hole is 50 degrees, meaning that the angle between the outermost borehole and the horizontal plane is 50 degrees, so that the borehole can cover the cracks in the roof and side shoulder areas.

[0035] The depth of the same row of water guide holes 3 decreases symmetrically from the centerline of the top plate to both sides. The deepest water guide hole 3 in the middle is designed to be 25 meters deep, and the depths of the holes on both sides are 23 meters, 20 meters, 17 meters, 14 meters, 11 meters and 10 meters respectively. The depth of the two outermost holes is 10 meters. Along the direction of the tunnel, the spacing between adjacent rows of water guide holes 3 is 2 meters. A total of 6 rows are constructed, with a total treatment length of 20 meters, covering the main seepage section of Area A. The diameter of the water guide holes 3 is uniformly adopted as 89 mm, which is the preferred value considering both drilling efficiency and water guiding capacity.

[0036] The hydraulic rock drilling rig was used to construct the water guide hole 3. Before construction, the rig was moved to the designed starting position to ensure that the center line of the rig was strictly aligned with the center line of the roadway, and a laser pointer was used for verification. The rig was used with a crowbar and a pry bar to thoroughly remove loose rocks from the roof and sides of the work area to ensure work safety.

[0037] When positioning the trolley, use the jack bases on both sides of the trolley as fixed reference points. When it is necessary to move the trolley to drill the next hole, move the trolley according to the designed hole spacing of 0.6 meters, and ensure that after the relocation, the distance between the two sides of the trolley and the two sides of the roadway is equal, and the deviation between the relocation position and the designed position is controlled within 5 centimeters.

[0038] When drilling, adjust the trolley's feed pressure to 20 bar, place the drill bit holder in the guide position, ensuring the drill bit accurately contacts the drilling point, and advance slowly. Once the drill bit has penetrated 20 cm into the intact rock mass, confirm the drilling direction is correct, then increase the feed pressure to 50 bar for normal drilling speed. During drilling, operators closely observe the backflow of cuttings and water output. When the borehole passes through a fault fracture zone, the backflow of cuttings may suddenly increase, accompanied by high-pressure water output. At this point, slow down the drilling speed and increase the flushing water volume to prevent the drill from getting stuck. Record the initial water output depth and stable water output for each hole. After drilling, use an electronic inclinometer to check if the hole depth, inclination angle, and azimuth meet the design requirements. The allowable error for single hole depth is ±0.3 meters, and the inclination angle error should not exceed 2 degrees. Holes with depth deviations exceeding the requirements should be drilled again.

[0039] Finally, as Figure 3 and 4 As shown, the water diversion system is installed. At the opening of each completed water diversion hole 3, a 0.5-meter-long orifice pipe 5 is installed. The orifice pipe 5 is made of galvanized steel pipe with an outer diameter matching the borehole diameter. The gap between the pipe wall and the borehole wall is filled tightly with quick-setting cement roll anchoring agent to ensure no leakage. After the anchoring agent solidifies, a water injection test is conducted to check the sealing performance of the orifice pipe 5. Subsequently, below the orifice pipe 5, an arc-shaped main water diversion pipe 7 is laid along the cross-section of the tunnel. The main water diversion pipe 7 is made of PVC pipe with a diameter of 126 mm, which has the advantages of corrosion resistance, smooth inner wall, and low water resistance.

[0040] Before installation, according to the position of each orifice pipe 5, a corresponding T-shaped interface 6 is reserved on the main water guide pipe 7 using a hot air welding gun. The inner diameter of the T-shaped interface 6 and the outer diameter of the orifice pipe 5 form a socket fit. The main water guide pipe 7 is pressed tightly against the tunnel wall, and the curvature is adjusted to basically match the arched contour of the tunnel, so that the lower opening of each orifice pipe 5 can be accurately inserted into the corresponding T-shaped interface 6, with an insertion depth of not less than 10 cm.

[0041] Expansion bolts and pipe clamps 4 are used as fasteners to securely fix the main water diversion pipe 7 to the tunnel wall. Specifically, the expansion bolts and pipe clamps 4 are spaced 1.5 meters apart, with denser installation at joints and bends to prevent the main water diversion pipe 7 from loosening due to water flow impact or vibration. Finally, the two outlets of the main water diversion pipe 7 are connected to the bottom of the drainage ditches 2 on both sides of the tunnel through a section of bend and a reducing joint, so that the outlets are submerged in the water surface of the ditch to reduce noise and splashing. In this way, the seepage water flowing out of the water diversion hole 3 flows into the main water diversion pipe 7 through the orifice pipe 5 and T-shaped joint 6, and then flows along the main water diversion pipe 7 by gravity to the drainage ditches 2 on both sides of the tunnel, and is finally discharged into the water tank.

[0042] After the system is in operation, it is necessary to regularly check whether the water output of each water guide hole 3 is stable, and whether there is any leakage or blockage at the pipe connection. Specifically, in the initial stage of operation, check once a day; after stable operation, check once a week to confirm that no foreign objects have fallen into the main water guide pipe 7 and that the drainage is smooth.

[0043] Through the implementation of this process, the previously scattered water seepage from the roof of the roadway was effectively collected and discharged in an orderly manner, reducing the air humidity in the roadway, eliminating roof water seepage, and drying the floor without water accumulation, thus fundamentally improving the working environment. At the same time, due to the reduction in seepage pressure within the roof rock mass and the significant decrease in the phreatic line height, the softening effect of groundwater on weak surrounding rocks such as phyllite was effectively curbed. The water content of the treated surrounding rock decreased, the point load strength increased, and the engineering geological stability of the roof surrounding rock was significantly improved. Subsequent monitoring did not detect any new rockfalls or spalling phenomena, thereby eliminating the safety risk of roof collapse.

[0044] Those skilled in the art will understand that the specific drilling depth, angle, row spacing, borehole diameter, and trolley propulsion pressure parameters in the above embodiments are examples given based on specific tunnel cross-sectional dimensions, hydrogeological conditions, and construction equipment. In practical applications, the number of rows of water guide holes 3, the number of holes per row, the radial center height, the borehole depth gradient, the trolley model, the pipe diameter, and the material can be adaptively adjusted according to factors such as tunnel cross-sectional dimensions, rock mass fracturing degree, seepage volume, and surrounding rock lithology. For example, the forward inclination angle is not limited to 87 degrees and can be optimized within the range of 85 to 90 degrees based on the top strata attitude and fracture development angle. The connection method between the borehole pipe 5 and the main water guide pipe 7 is not limited to the T-type interface 6 plug-in connection and can also be a flange connection or a socket bonding connection. The fixing component is not limited to the expansion bolt pipe clamp 4 and can also be an anchor bolt plus clamp method. All the above adjustments do not depart from the technical concept of the present invention and are still within the protection scope of the present invention.

Claims

1. A method for treating seepage water from the roof of a roadway, characterized in that, Includes the following steps: Data preparation steps: Collect and analyze hydrogeological data of the mining area to determine the correlation area between surface recharge sources and roadway roof; Tunnel measurement steps: Perform three-dimensional measurement of the tunnel and establish a three-dimensional model of the tunnel; Tunnel logging steps: Conduct engineering geological and hydrogeological logging of the tunnels, identify seepage areas and seepage paths, and draw logging maps; Steps for determining the location of the water guide hole: Based on the logging diagram, superimpose the projection areas of the seepage area and the related area onto the roadway roof to determine the construction location of the water guide hole; Construction steps for water guide holes: At the construction location of the water guide holes, construct multiple rows of water guide holes along the roof of the roadway (3); Water diversion system installation steps: Install orifice pipe (5) at the orifice of each water diversion hole (3) and install a pipe network to collect and discharge seepage water to the roadway drainage ditch (2).

2. The tunnel roof seepage water treatment process according to claim 1, characterized in that, In the construction steps of the water guide holes, the multiple rows of water guide holes (3) are arranged in a rhomboid shape.

3. The tunnel roof seepage water treatment process according to claim 2, characterized in that, In the construction steps of the water guide holes, the depth of each row of water guide holes (3) gradually decreases from the center line of the roof in the roadway to both sides.

4. The tunnel roof seepage water treatment process according to claim 1, characterized in that, In the construction steps of the water guide hole: The water guide hole (3) is constructed using a hydraulic trolley, and the pushing pressure during hole opening is the first pushing pressure. Once the drill bit has penetrated to the predetermined depth in the rock, the propulsion pressure is adjusted to the second propulsion pressure for rock drilling. The second propulsion pressure is greater than the first propulsion pressure.

5. The tunnel roof seepage water treatment process according to claim 4, characterized in that, When constructing the water guide hole (3), align the centerline of the hydraulic trolley with the centerline of the roadway, and use the jack bases on both sides of the trolley as reference points for relocation and positioning, controlling the deviation between the relocation position and the design position.

6. The tunnel roof seepage water treatment process according to claim 1, characterized in that, In the installation steps of the water diversion system, the pipeline network includes an arc-shaped main water diversion pipeline (7) laid along the cross-section of the roadway, and a T-shaped interface (6) is reserved on the main water diversion pipeline (7).

7. The tunnel roof seepage water treatment process according to claim 6, characterized in that, The specific installation steps for the water guiding system are as follows: Install a hole pipe (5) at the opening of each water guide hole (3); An arc-shaped main water-guiding pipe (7) is laid along the cross-section of the tunnel. A T-shaped interface (6) is reserved on the main water supply pipe (7), and the position of the T-shaped interface (6) corresponds to the position of the orifice pipe (5); Insert the lower end of the orifice pipe (5) into the corresponding T-type interface (6); Fix the main water diversion pipe (7) to the tunnel arm; Connect the end of the main water diversion pipe (7) to the drainage ditch (2) on both sides of the roadway.

8. The tunnel roof seepage water treatment process according to claim 1, characterized in that, In the construction steps of the water guide hole, the radial center of the water guide hole (3) is located at the center line of the roadway.

9. The tunnel roof seepage water treatment process according to claim 1, characterized in that, In the construction steps of the water guide hole, the water guide hole (3) includes a middle water guide hole and a side water guide hole, and the depth of the middle water guide hole is greater than the depth of the side water guide hole.

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