A device and method for blocking high-pressure water inrush in karst areas by advanced exploration of tunnels

Abstract

The present invention discloses a device and method for blocking high-pressure water inrush in karst of tunnel advance exploration hole. The device comprises a tunnel advance exploration hole that penetrates the surrounding rock between the tunnel face and the karst pipeline. The tunnel advance exploration hole is provided with an inlet pipe on one side of the tunnel face. One end of the inlet pipe extends from the tunnel face into the tunnel advance exploration hole, and the other end is connected to a diversion pipe 1 and a diversion pipe 2 that form a bifurcated pipe structure; the diversion pipe 1 is connected to the drainage pipe 1 through a reducer 1, and the drainage pipe 1 leads to a sump; the diversion pipe 2 is connected to the drainage pipe 2 through a reducer 2, and the drainage pipe 2 is connected to a grouting pipe. A high-pressure gate valve 1 and a high-pressure gate valve 2 are respectively provided on the diversion pipe 1 and the diversion pipe 2. The present invention is to directly install a "diversion-drainage-grouting" processing device at the orifice and then select an opportunity to grout and block. On the one hand, it can avoid the adverse effects of the diversion method of the drainage hole on the groundwater ecological environment, and on the other hand, it increases the water-passing section and effectively reduces the water gushing velocity.

Description

Technical Field

[0001] The invention belongs to the field of tunnel engineering and underground cavern engineering, and relates to a plugging treatment structure and a treatment method suitable for a tunnel advance exploration hole after karst high-pressure water gushing occurs. Background Art

[0002] In order to obtain geological information ahead of the excavation face during tunnel construction, advance geological drilling is usually used for advance geological forecasting. Tunnel advance drilling generally uses impact drills, which have a fast drilling speed and can roughly explore the geological conditions ahead through the sound of the impactor, drilling speed and its changes, rock powder, drill sticking, drill rod vibration, flushing fluid color and flow changes, etc. The disadvantage is that it cannot be cored. When drilling ahead in complex geological areas or special destination areas, rotary coring drills are generally used. Rotary coring drills can accurately and reliably identify cores, and the mileage of formation changes can be accurately determined. The disadvantage is that the drilling speed is slow.

[0003] When constructing tunnels in karst areas, when the tunnel is buried deep and the karst pipelines are well developed within the tunnel excavation range, the groundwater head in the pipeline is high. Due to the fast construction speed of impact drilling, advance drilling is mostly done by impact drilling, but impact drilling is usually done in bare holes without orifice protection devices. When it penetrates the high-pressure, water-rich karst pipeline, there is a high possibility of high-pressure karst water gushing in the advance drilling. Under the action of high water head, the water gushing from the borehole has a high injection rate, which poses a great safety hazard to personnel, equipment and the project itself. When the groundwater flow is large, it may also cause the tunnel section near the face to be flooded, and the subsequent treatment technology is extremely difficult.

[0004] In order to deal with high-pressure karst water gushing in tunnel advance exploration, indirect methods such as diversion through drainage holes, pouring concrete water-blocking walls and then grouting to seal are usually used, as well as direct sealing methods such as installing straight grouting anchor rods with bags. The diversion treatment of drainage holes requires the excavation of several kilometers of drainage holes to the karst pipeline exposed by the advance exploration holes, which requires large investment and long construction period, and has a great impact on the surrounding groundwater environment. The pouring of concrete water-blocking walls and then grouting to seal requires pumping out water and then diverting and pouring concrete in sections. The treatment time is long, and pouring concrete in a dynamic water environment is difficult. The existing direct treatment methods are mostly to wrap a bag around the outside of the straight grouting anchor rod, anchor the straight grouting anchor rod to the inner wall of the borehole by grouting into the bag, and finally grouting the grouting anchor rod to seal the water gushing. There are two major disadvantages of direct sealing with straight grouting anchor rods. First, the anchoring force provided by the anchor rod outer sleeve is limited. When the water gushing velocity is particularly high, the device is easy to fall off and eject, resulting in sealing failure. Second, during the installation process, water gushes out in one direction through the straight grouting anchor rod, and the water-passing cross-section is not effectively increased. The water gushing velocity is still high, which poses a great safety hazard to the operators. Summary of the invention

[0005] The purpose of the present invention is to provide a fast, safe and low-cost method for treating high-pressure karst water gushing in tunnel advance exploration holes by directly treating the water gushing hole.

[0006] The technical solution of the present invention is as follows:

[0007] A tunnel advance exploration hole karst high-pressure water inrush plugging device includes a tunnel advance exploration hole that penetrates the surrounding rock between the tunnel face and the karst pipeline, the tunnel advance exploration hole is provided with an inlet pipe on one side of the tunnel face, one end of the inlet pipe extends from the tunnel face into the tunnel advance exploration hole, and the other end is connected to a diversion pipe 1 and a diversion pipe 2 that form a bifurcated pipe structure; the diversion pipe 1 is connected to a drainage pipe 1 through a reducer 1, and the drainage pipe 1 leads to a sump; the diversion pipe 2 is connected to a drainage pipe 2 through a reducer 2, and the drainage pipe 2 is connected to a grouting pipe. A high-pressure gate valve 1 and a high-pressure gate valve 2 are provided on the diversion pipe 1 and the diversion pipe 2, respectively.

[0008] The specific blocking method includes the following steps:

[0009] Step 1: Add a sewage pump to make the pumping flow greater than the water flow, and continue to pump water from the working area until machinery and personnel can enter the water gushing area.

[0010] Step 2, open all the gate valves on the device of the present invention, keep water flowing through all the diversion pipes, use excavators and loaders to lift, and manually cooperate to extend the inlet pipe wrapped with green hemp used in the device of the present invention into the water advance exploration hole, and use the excavator to increase the inlet length of the inlet pipe as much as possible.

[0011] Step three: keep all gate valves in the open state, divert the flow to release pressure and reduce the injection rate, and use steel bars, steel strands, steel pipes and other materials to anchor the orifice device to the surrounding rock and the primary support steel arch frame.

[0012] Step 4: Keep the gate valve on one side of the diversion pipe open to allow the gushing water to be discharged from the diversion pipe on that side; close the gate valve on the other side of the diversion pipe, and then connect it to a drainage pipe with a larger diameter through a reducer flange. The drainage pipe is laid along the side wall of the tunnel to a sump away from the heading.

[0013] Step five, open the gate valve on the side of the diversion pipe that has been connected to the drainage pipe, and let the gushing water discharge through the diversion pipe and the drainage pipe on this side; then close the gate valve on the diversion pipe that has not been connected to the drainage pipe, and then connect the larger diameter drainage pipe through the reducer flange, and lay it along the side wall on the other side of the tunnel to a position that is convenient for connecting to the grouting pipe.

[0014] Step six, open all gate valves, keep the pipelines on both sides in the drainage state, divert the flow to release pressure and reduce the injection rate, pour concrete piers at the orifice and anchorage parts of the device to further strengthen the orifice device.

[0015] Step seven, after the poured concrete pier reaches the designed strength, keep the gate valve on the diversion pipe on the side leading to the sump open to allow the gushing water to be discharged through the pipe on this side; then close the gate valve on the diversion pipe on the other side and connect the grouting pipeline to the end of the diversion pipe on this side.

[0016] Step 8: Close the gate valve on the pipeline leading to the sump to ensure that the slurry will not leak through the pipeline during grouting. Open all the gate valves on the pipeline connected to one side of the grouting pipeline, pour the quick-setting paste slurry, and inject the slurry into the karst pipeline through the pipeline on one side of the grouting pipeline. After reaching the end standard of grouting, close all the gate valves to screen the slurry and wait for it to solidify.

[0017] Step 9: After the setting time is reached, open the gate valves on both sides of the pipeline respectively to check whether there is still water gushing out at the outlets of the pipelines on both sides, or whether the water gushing flow meets the design requirements. If it does not meet the design requirements, close all valves and arrange grouting holes on the face for reinforcement grouting until there is no water gushing out at the outlets of the pipelines on both sides after the valves are opened or the water gushing flow meets the design requirements.

[0018] In the above operation, it is required that the diameter of the inlet pipe of the orifice device extending into the advance exploration hole section is 5 to 10 mm smaller than the diameter of the advance exploration hole, the diameter of the diversion pipe is not less than the diameter of the advance exploration hole, the diameter of the drainage pipe is 30 to 50 mm larger than the diameter of the diversion pipe, and the gate valves are all high-pressure gate valves with a withstand pressure of not less than 1.5 to 2 times the water gushing pressure.

[0019] The present invention increases the outlet flow rate of gushing water, reduces the outlet gushing water injection speed and reduces safety hazards through two-stage large-diameter shunt pipes; the water control valve on the device can control the drainage and dynamically control the water flow rate, which is conducive to the pumping of accumulated water; the drainage pipe guides the gushing water after diversion away from the gushing water face, creating a dry operating environment for reinforcing the device or reinforcing the surrounding rock of the face; the treatment device is anchored to the surrounding rock and the initial support steel arch frame through steel bars, steel strands, etc., and then concrete piers are poured, providing sufficient anchoring force and a higher safety factor; the end of the drainage pipe is connected to the grouting pipe, and the quick-setting paste slurry is poured to gradually move the groundwater to the deep part of the karst pipeline outside the tunnel range; after the grouting is completed, the shunt pipe valve can be opened to check the grouting effect, and it is reasonable to choose whether to reinforce the grouting.

[0020] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: the present invention directly installs a "diversion-drainage-grouting" treatment device at the hole mouth and then selects an opportunity to grout and seal it. On the one hand, it can avoid the adverse effects of the diversion method of the drainage tunnel on the groundwater ecological environment, and has a shorter treatment time and lower cost than indirect treatment methods such as diversion of drainage tunnels, pouring concrete water-blocking walls, and then grouting and sealing. On the other hand, compared with the direct sealing method of straight grouting anchor rods, the water-passing cross-section is increased by diversion and diameter change, which effectively reduces the injection velocity of the gushing water outlet, and the gushing water is diverted a long distance away from the heading face before grouting treatment, which significantly improves safety. The present invention has a good effect on the treatment of karst gushing water in tunnel advance exploration holes with high pressure, large flow, and high injection velocity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the present invention.

[0022] Explanation of the accompanying numbers: 1-karst pipeline, 2-tunnel advance exploration hole, 3-surrounding rock, 4-tunnel face, 5-entry pipe, 6-reinforcement anchor rod, 7-concrete pier, 8-diversion pipe one, 9-diversion pipe two, 10-high-pressure gate valve one, 11-high-pressure gate valve two, 12-drainage pipe one, 13-drainage pipe two, 14-reducing joint one, 15-reducing joint two, 16-collecting pit, 17-grouting pipe, 18-tunnel side wall. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0024] like Figure 1 As shown, the plugging system of the present invention includes a tunnel advance exploration hole 2 that penetrates the surrounding rock 3 between the tunnel face 4 and the karst pipeline 1. The tunnel advance exploration hole 2 is provided with an entry hole pipe 5 on one side of the tunnel face 4. One end of the entry hole pipe 5 extends from the tunnel face 4 into the tunnel advance exploration hole 2, and the other end is connected to the diversion pipe 1 8 and the diversion pipe 2 9 that form a bifurcated pipe structure; the diversion pipe 1 8 is connected to the drainage pipe 1 12 through the reducer 1 14, and the drainage pipe 1 12 leads to the sump 16; the diversion pipe 2 9 is connected to the drainage pipe 2 13 through the reducer 2 15, and the drainage pipe 2 13 is connected to the grouting pipe 17. In addition, the diversion pipe 1 8 and the diversion pipe 2 9 are respectively provided with a high-pressure gate valve 10 and a high-pressure gate valve 2 11.

[0025] When the present invention is specifically implemented, it is carried out according to the following steps:

[0026] Step 1: Add a sewage pump to make the pumping flow greater than the water flow, and continue to pump water from the working area until machinery and personnel can enter the water gushing area.

[0027] Step 2, open the valves of the gate valves on all the devices of the present invention (high-pressure gate valve 1 10, high-pressure gate valve 2 11), keep the diversion pipe 1 8 and the diversion pipe 2 9 both flowing with water, use an excavator and a loader to lift, and manually cooperate to extend the entry pipe 5 of the device of the present invention into the tunnel advance exploration hole 2, and use the excavator to increase the extension length of the entry pipe 5 as much as possible.

[0028] Step three, keep all gate valves (high pressure gate valve 1 10, high pressure gate valve 2 11) in an open state, use steel bars, steel strands, steel pipes and other materials to form an anchor system with reinforcement anchor rods 6 as the main body, and anchor the device to the surrounding rock 3 and the primary support steel arch frame.

[0029] Step 4, keep the valve of high-pressure gate valve 11 open to allow diversion pipe 9 to drain water; close the valve of high-pressure gate valve 10, connect a larger-diameter drainage pipe 12 to the high-pressure gate valve 10 through a reducer 14 flange, and lay it along one side of the tunnel side wall 18 to the sump 16 away from the tunnel face 4.

[0030] Step five, open the valve of high-pressure gate valve 10, let the gushing water pass through the diversion pipe 8 and the drainage pipe 12 into the sump 16 for centralized pumping; then close the valve of high-pressure gate valve 2 11, and then connect the larger diameter drainage pipe 2 13 through the flange of reducer 2 15, and the drainage pipe 2 13 is laid along the tunnel side wall 18 on the other side of the tunnel.

[0031] Step six, open the high-pressure gate valve 10 and the high-pressure gate valve 2 11, keep the pipelines on both sides in a drainage state, pour concrete piers 7 at the orifice and anchoring positions to further reinforce the orifice device.

[0032] Step seven, after the concrete pier 7 to be poured reaches the design strength, keep the valve of the high-pressure gate valve 10 in the open state to allow the diversion pipe 8 and the drainage pipe 12 to drain water; then close the high-pressure gate valve 2 11 on the diversion pipe 9, and connect the grouting pipe 17 to the drainage pipe 13.

[0033] Step eight, close the valve of high-pressure gate valve 10, the purpose is to ensure that the slurry will not escape through the shunt pipe 18-drainage pipe 12 pipeline during grouting and plugging. Open the high-pressure gate valve 2 11, inject the quick-setting paste slurry through the grouting pipe 17, and send the quick-setting paste slurry into the gushing karst pipeline through the drainage pipe 2 13-shunt pipe 2 9-tunnel advance exploration hole 2 line. The grouting pressure is the sum of the gushing pressure and the designed grouting pressure. After the grouting reaches the end standard, close the high-pressure gate valve 10 and the high-pressure gate valve 2 11 to screen the slurry and wait for solidification.

[0034] Step 9: After the setting time is reached, open the high-pressure gate valve 10 and the high-pressure gate valve 2 11 in sequence, and check whether there is still water gushing out of the drainage pipe 12 and the drainage pipe 2 13, or whether the water gushing flow meets the design requirements. If it does not meet the design requirements, close all valves, arrange grouting holes on the tunnel face 4 for reinforcement grouting, until there is no water gushing out of the drainage pipe 1 12 and the drainage pipe 2 13 after the valve is opened.

[0035] The present invention has been successfully applied in the grouting and water blocking project of Dejiang Tunnel on Dejiang-Wuchuan Expressway in Guizhou Province. In this project, the tunnel advance exploration hole 2 is φ80mm, the inlet pipe 5 of the device is selected as a φ75mm steel pipe, the diversion pipe 1 8 and the diversion pipe 2 9 are selected as φ80mm steel pipes, the drainage pipe 1 12 and the drainage pipe 2 13 are selected as φ130mm steel pipes, the water gushing pressure is about 2MPa, and the gate valve is selected as a 4.0MPa high-pressure gate valve.

[0036] Of course, the above are only specific application examples of the present invention. The present invention has other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A method for sealing karst high-pressure water inrush in advance exploration of a tunnel, characterized in that: A tunnel advance exploration hole karst high-pressure water-gushing plugging device is used, the device comprising a tunnel advance exploration hole (2) penetrating the surrounding rock (3) between the tunnel face (4) and the karst pipeline (1); the tunnel advance exploration hole (2) is provided with an entry hole pipe (5) on one side of the tunnel face (4); one end of the entry hole pipe (5) extends from the tunnel face (4) into the tunnel advance exploration hole (2); the other end of the entry hole pipe (5) is connected to a diversion pipe 1 (8) and a diversion pipe 2 (9) forming a bifurcated pipe structure; the diversion pipe 1 (8) is connected to a drainage pipe 1 (12) via a reducer 1 (14); the drainage pipe 1 (12) leads to a sump (16); the diversion pipe 2 (9) is connected to a drainage pipe 2 (13) via a reducer 2 (15); the drainage pipe 2 (13) is connected to a grouting pipe (17); The steps include: S1, add sewage pumps to make the pumping flow greater than the water flow, and continue to pump water from the working area until machinery and personnel can enter the water gushing area; S2, open the high-pressure gate valve 1 (10) and the high-pressure gate valve 2 (11), keep the diversion pipe 1 (8) and the diversion pipe 2 (9) flowing with water, and use an excavator and a loader to lift and extend the entry pipe (5) into the tunnel advance exploration hole (2); S3, keep the high-pressure gate valve 1 (10) and the high-pressure gate valve 2 (11) in an open state, and use materials including steel bars, steel strands, and steel pipes to form an anchor system to anchor the device to the surrounding rock and the primary support steel arch frame; S4, keep the valve of high-pressure gate valve 2 (11) open to allow diversion pipe 2 (9) to drain water; close the valve of high-pressure gate valve 1 (10), connect a larger-diameter drainage pipe 1 (12) to the high-pressure gate valve 1 (10) through a reducer 1 (14) flange, and lay it along the tunnel side wall (18) on one side to a sump (16) away from the tunnel face (4); S5, open the valve of high-pressure gate valve 1 (10), let the gushing water flow through the diversion pipe 1 (8) and the drainage pipe 1 (12) into the sump (16) and then be centrally pumped out; then close the valve of high-pressure gate valve 2 (11), and then connect the larger diameter drainage pipe 2 (13) through the flange of reducer 2 (15), and the drainage pipe 2 (13) is laid along the tunnel side wall (18) on the other side; S6, open the high-pressure gate valve 1 (10) and the high-pressure gate valve 2 (11), keep the pipelines on both sides in a drainage state, and pour concrete piers (7) at the orifice and anchoring positions; S7, after the poured concrete pier (7) reaches the designed strength, the valve of the high-pressure gate valve 1 (10) is kept in an open state, so that the diverter pipe 1 (8) and the drainage pipe 1 (12) can drain water; then the high-pressure gate valve 2 (11) on the diverter pipe 2 (9) is closed, and the grouting pipe (17) is connected to the drainage pipe 2 (13); the high-pressure gate valve 1 (10) and the high-pressure gate valve 2 (11) are respectively provided on the diverter pipe 1 (8) and the diverter pipe 2 (9); S8, close the valve of the high-pressure gate valve 1 (10), open the high-pressure gate valve 2 (11), inject the quick-setting paste slurry through the grouting pipe (17), and inject the quick-setting paste slurry into the gushing karst pipeline (1) through the drainage pipe 2 (13) - diversion pipe 2 (9) - tunnel advance exploration hole (2) line; after the grouting reaches the end standard, close the high-pressure gate valve 1 (10) and the high-pressure gate valve 2 (11) to screen the slurry and wait for it to solidify; S9, after the setting time is reached, open the high-pressure gate valve 1 (10) and the high-pressure gate valve 2 (11) in sequence, and check whether there is still water gushing out of the drainage pipe 1 (12) and the drainage pipe 2 (13), or whether the water flow rate meets the design requirements. If it does not meet the design requirements, close all valves again, arrange grouting holes on the tunnel face (4) for reinforcement grouting, until there is no water gushing out of the drainage pipe 1 (12) and the drainage pipe 2 (13) after the valves are opened.

2. The method for sealing karst high-pressure water inrush in advance exploration holes of a tunnel according to claim 1 is characterized by: A reinforced concrete pier (7) is provided at the opening of the tunnel advance exploration hole (2) to wrap the entry hole pipe (5).

3. The method for blocking karst high-pressure water inrush in advance exploration holes of a tunnel according to claim 1 is characterized by: The entry tube (5) is wrapped with green hemp.

4. The method for blocking high-pressure water inrush in karst tunnels by advanced exploration of tunnels according to claim 1 is characterized by: The diverter pipe 1 (8) and the diverter pipe 2 (9) are branched from the opening of the tunnel advance exploration hole (2) to the tunnel side walls (18) on both sides.

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