Ground negative pressure feeding system for water inrush closure and plugging of deep-buried tunnel

Abstract

The invention discloses a ground negative pressure feeding system for water inrush closure and plugging of a deep-buried tunnel. The ground negative-pressure feeding system comprises a pipeline, an adjustable-speed jet flow pump, a directional roadway-penetrating drill hole sleeve and a hopper, a directional roadway-penetrating drill hole communicated with a water gushing tunnel is formed in the ground, a second end of the directional roadway-penetrating drill hole sleeve is inserted into the directional roadway-penetrating drill hole and communicated with fluid of the water gushing tunnel, the adjustable-speed jet flow pump is arranged on the ground, and a second end of the directional roadway-penetrating drill hole sleeve is inserted into the directional roadway-penetrating drill hole and communicated with fluid of the water gushing tunnel. The water outlet end of the speed-adjustable jet flow pump is connected with the first end of the pipeline, and the second end of the pipeline is connected with the first end of the directional roadway penetrating drilling sleeve. According to the system provided by the invention, by optimizing the flow speed and the mixing proportion of the water flow carrying the gravel aggregate, the common problems of hole blockage, air column formation and the like in a traditional feeding mode are effectively avoided, and the aims of high efficiency, safety and economy of emergency treatment of water inrush of the deep-buried tunnel are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of blocking and controlling water inrush in deep buried tunnels and lanes, and more specifically to a ground negative pressure feeding system for blocking and controlling water inrush in deep buried tunnels. Background Art

[0002] As the scale of underground space development and utilization continues to expand, projects such as transportation tunnels, mine tunnels, and water conservancy tunnels are increasing. Some areas have rich groundwater systems, and there may be water-conducting channels such as faults, fissures, and caves in the strata. These underground projects face a high risk of sudden water inrush when crossing areas with complex geological structures. That is, when construction disturbs these areas, groundwater will flow into tunnels or tunnels under pressure. From the perspective of engineering construction, due to the limitations of preliminary geological surveys, technicians may not be able to fully and accurately grasp the underground geological and hydrological conditions, resulting in insufficient preventive measures against sudden water inrush during construction.

[0003] Water inrush accidents may cause casualties, equipment damage and project stagnation, causing huge losses to construction units and society. From an economic perspective, water inrush not only increases the direct cost of project management, but also causes construction delays, indirectly increasing the total cost of the project. In addition, the outflow of a large amount of untreated groundwater may have an adverse impact on the surrounding ecological environment and water resource balance. In order to ensure the safety and smooth progress of underground projects, protect the environment and save costs, it is necessary to carry out interception and plugging of water inrush in tunnels and roadways.

[0004] The ground directional through-tunnel drilling and feeding to intercept and plug the water is the primary task of deep-buried tunnels and tunnels for water inrush and gushing, and it is also one of the key tasks to form an accumulation in the water-gushing tunnel to reduce the water-passing section. The treatment of water inrush and gushing in deep-buried tunnels and tunnels is usually an emergency rescue project, and the efficiency of ground feeding directly affects the efficiency of emergency rescue. The traditional feeding method is to feed aggregates dry or to pour aggregates and water at the orifice at the same time, which cannot efficiently form an accumulation in the water-gushing tunnel or tunnel, and often causes aggregates to block the hole, which takes time and material to repeatedly sweep the hole. What's more, an air column is formed in the borehole, which causes the harm of aggregates spraying from the air mouth under the condition of pressure holding, which seriously restricts the smooth progress of emergency water plugging work in deep-buried tunnels and tunnels. Therefore, the development of a ground negative pressure feeding system for intercepting and plugging water inrush in deep-buried tunnels is of great significance to ensure the rapid, efficient and safe treatment of water inrush and gushing in deep-buried tunnels and tunnels. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide a ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels. The system effectively avoids the common problems of hole plugging and air column formation in traditional feeding methods by optimizing the flow rate and mixing ratio of sand and gravel aggregates carried by water flow, and achieves the goal of efficient, safe and economical emergency treatment of water inrush in deep buried tunnels.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A ground negative pressure feeding system for blocking and plugging water inrush in a deep-buried tunnel comprises a pipeline, an adjustable-speed jet pump, a directional tunnel drilling casing and a hopper. A directional tunnel drilling hole communicating with a water gushing tunnel is provided on the ground. The second end of the directional tunnel drilling casing is inserted into the directional tunnel drilling hole and communicates with the fluid of the water gushing tunnel. The adjustable-speed jet pump is arranged on the ground. The water outlet of the adjustable-speed jet pump is connected to the first end of the pipeline, and the second end of the pipeline is connected to the first end of the directional tunnel drilling casing. The discharge port of the hopper is connected and communicated with the pipeline, and graded sand and gravel aggregates are contained in the hopper. The adjustable-speed jet pump supplies high-speed water flow into the pipeline, and the graded sand and gravel aggregates in the hopper enter the pipeline through the discharge port and enter the directional tunnel drilling casing after being mixed with the high-speed water flow. The high-speed water flow drives the graded sand and gravel aggregates into the water gushing tunnel to form an aggregate accumulation body. The adjustable speed jet pump is used to control the speed of the water flow in the pipeline so that the water flow carries the graded sand and gravel aggregates and flows at a uniform speed in the water delivery pipeline. The pipeline is a conveying channel for water flow on the ground. The material is a national standard 16Mn seamless steel pipe with a wear-resistant material lining. Its wall thickness and pipe diameter are determined based on the aggregate particle size and flow rate.

[0008] The above-mentioned ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels, the pipeline is divided into a horizontal section parallel to the ground, a curved pipe section and a straight pipe section perpendicular to the ground, along the direction from the first end to the second end of the pipeline: the horizontal section, curved pipe section and straight pipe section of the pipeline are sequentially connected and fluidly connected; the discharge port of the hopper is fluidly connected with the middle part of the horizontal section. When the adjustable speed jet pump drives the water flow in the pipeline, a negative pressure is formed at the connection between the discharge port of the hopper and the pipeline, and at the same time, the graded sand and gravel aggregates in the hopper fall under the action of their own weight, and the graded sand and gravel aggregates are more easily sucked into the pipeline and flow forward with the water flow.

[0009] The above-mentioned ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels further comprises a pressure relief valve arranged on the straight pipe section of the pipeline.

[0010] The above-mentioned ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels, the ground negative pressure feeding system also includes a baffle, a baffle bracket, a connecting rod and a first connecting valve, the first connecting valve is a gate valve, the first connecting valve includes a valve stem and a gate connected to the second end of the valve stem; the first end of the baffle extends into the lumen of the pipeline, and the plate surface of the baffle is perpendicular to the direction of water flow in the pipeline, the second end of the baffle passes through the pipe wall of the pipeline and is hinged to the first end of the connecting rod outside the lumen of the pipeline; The second end of the connecting rod is hinged to the first end of the valve stem; the baffle bracket is fixedly installed on the outside of the pipe wall of the pipeline, and the baffle bracket is hinged at the middle of the baffle, and the hinge axis of the baffle bracket and the baffle is perpendicular to the extension direction of the pipeline; the first connecting valve is installed on the passage between the discharge port of the hopper and the pipeline, and the gate of the first connecting valve directly controls the opening and closing of the passage; when the water flow in the pipeline pushes the baffle, the discharge port of the hopper and the passage between the pipeline are connected.

[0011] The above-mentioned ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels, during the drilling construction of the directional tunnel drilling hole, the end away from the ground is drilled to 1m below the bottom plate of the water inrush tunnel.

[0012] In the above-mentioned ground negative pressure feeding system for blocking and plugging water inrush in deep buried tunnels, the directional tunnel drilling casing is divided into a first directional tunnel drilling casing and a second directional tunnel drilling casing; the upper end of the first directional tunnel drilling casing is conductively connected to the pipeline, the lower end of the first directional tunnel drilling casing is conductively connected to the upper end of the second directional tunnel drilling casing, and the inner diameter of the first directional tunnel drilling casing is greater than the inner diameter of the second directional tunnel drilling casing; the first directional tunnel drilling casing extends vertically downward from the ground to 5 to 15 meters below the bedrock in the stratum, and the lower end of the second directional tunnel drilling casing is flush with the top plate of the water-gushing tunnel. During the drilling construction of the directional tunnel drilling, the drilling is carried out in two sections. The first section is drilled to 5 to 15 meters below the bedrock in the bottom layer, and the first directional tunnel drilling casing is lowered. The second section is drilled to 1 meter below the bottom plate of the water-gushing tunnel, and the second directional tunnel drilling casing is lowered. The two-stage method can speed up the drilling rate and improve the hole quality. In addition, the directional tunnel drilling to 1m below the bottom plate of the water-gushing tunnel can facilitate the construction personnel to detect the bottom plate, and at the same time increase the contact area between the poured graded sand and gravel aggregate and the bottom plate, so that the bottom of the aggregate accumulation body formed by the graded sand and gravel aggregate forms a pile-like structure. The pile is inserted into the bottom plate of the water-gushing tunnel, which can improve the ability of the aggregate accumulation body to resist water flow impact.

[0013] The above-mentioned ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels, when the ground negative pressure feeding system is in operation, the graded sand and gravel aggregates contained in the hopper enter the pipeline and mix with the water in the pipeline to form a sand-carrying water flow; the flow rate of the sand-carrying water flow in the pipeline is greater than or equal to the free falling rate of the graded sand and gravel aggregates in still water. After the graded sand and gravel aggregates in the sand-carrying water flow enter the water-bursting tunnel, they are accumulated on the bottom plate of the water-bursting tunnel to form an aggregate accumulation body.

[0014] The above-mentioned ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels, when the sand-carrying water flow enters the water-gushing tunnel, the flow rate of the sand-carrying water flow is 1.3 to 2.0 times the flow rate of the water in the water-gushing tunnel. There is a large difference between the flow rate of the water flow that does not carry graded sand and gravel aggregates and the flow rate of the sand-carrying water flow in the pipeline. When the flow rate of the sand-carrying water flow in the pipeline is too high, the graded sand and gravel aggregates may not be able to form an aggregate accumulation in the water-gushing tunnel. If the flow rate of the sand-carrying water flow is too low, it is easy to cause problems such as pipe blockage. When the sand-carrying water flow enters the water-gushing tunnel, its flow rate should be 1.3 to 2.0 times the flow rate of the water in the water-gushing tunnel. This is because, when the flow rate of the sand-carrying water entering the water-gushing tunnel is too low, the gushing water in the tunnel may wash away the graded sand and gravel aggregates, making it difficult to form aggregate accumulation on the tunnel floor; and when the flow rate of the sand-carrying water entering the water-gushing tunnel is too high, the sand-carrying water will impact the tunnel floor with a greater force, easily dispersing the aggregate accumulation that has been formed.

[0015] The above-mentioned ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels, the ground negative pressure feeding system also includes a flow rate monitoring meter and a pressure monitoring meter arranged in sequence from the first end of the pipeline to the second end of the pipeline, and the flow rate monitoring meter is arranged on the pipeline on the downstream side of the hopper. The pressure monitoring meter has a range of -1MPa to 10MPa. When the pressure monitoring meter is at a negative value, it indicates that the working state is normal. When the pressure monitoring meter is at a positive value, it indicates that the working state is abnormal, there is a risk of plugging or plugging has occurred. The pressure monitoring meter is also equipped with an alarm flashing light. When the pressure monitoring meter measures that the pressure in the pipeline is greater than 1MPa, the alarm flashing light will flash, indicating that the borehole exists or has been blocked. At this time, the hopper discharge port and the water storage pump and the adjustable speed jet pump can be closed, and the pressure relief valve can be opened to avoid pipeline and borehole pressure accidents. At the same time, the pipe blockage and hole blockage accidents can be quickly handled to ensure that the graded sand and gravel aggregates are smoothly transported to the water tunnel through the ground directional through-lane drilling holes to form an aggregate accumulation body and reduce the water-passing section. The function of the flow rate monitoring meter is to monitor the flow rate of the graded sand and gravel aggregates carried by the water flow in the pipeline in real time, to ensure that the flow rate of the graded sand and gravel aggregates carried by the water flow is not lower than the free falling speed of the graded sand and gravel aggregates in still water. When the flow rate of the sand-carrying water flow is low, the flow rate of the sand-carrying water flow can be increased by the adjustable speed jet pump.

[0016] The above-mentioned ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels, the graded sand and gravel aggregate is a mixture of sand and gravel with a particle size distribution between 1mm and 50mm and containing multiple different particle sizes, and the porosity of the graded sand and gravel aggregate is 10% to 20%. The graded sand and gravel aggregate is made by mixing sand and gravel with different particle sizes of 1mm to 50mm at a certain solid ratio, and the solid ratio is determined according to the porosity of the graded sand and gravel aggregate. When the porosity of the graded sand and gravel aggregate exceeds this range, its physical and mechanical properties and anti-permeability performance are poor, and it cannot meet the requirements of intercepting and plugging water inrush in deep buried tunnels.

[0017] The technical solution of the present invention achieves the following beneficial technical effects:

[0018] 1. The ground negative pressure feeding system provided in the present invention ensures that the flow rate of the sand-carrying water flow is not lower than the free settling speed of the aggregate by adjusting the water flow velocity and the mixing ratio of the sand and gravel aggregates, which greatly reduces the risk of hole blockage and air column formation, and the success rate and efficiency of ground directional tunnel drilling and placement of graded sand and gravel aggregates. At the same time, it can quickly form aggregate accumulation bodies in water-gushing tunnels and lanes, reduce the water-passing section, and lay the foundation for the next step of grouting reinforcement. When pipe or hole blockage occurs, the pressure relief operation of the pressure relief valve of the ground negative pressure feeding system can achieve rapid pressure relief of the pipeline, save time in dealing with hole blockage accidents, and ensure the smooth progress of emergency rescue and water blocking work.

[0019] 2. The ground negative pressure feeding system of the present invention is simple in design and easy to operate, and is convenient for rapid deployment and use under various complex geological conditions. Through the automatic monitoring and adjustment functions, users can control the feeding process in real time to ensure the best feeding effect. At the same time, the positive warning function of pressure monitoring ensures the safety of feeding work.

[0020] 3. The ground negative pressure feeding system provided in the present invention significantly reduces the shutdown and rework costs caused by water inrush during the construction process, while reducing the dependence on manpower and material resources, improving the feeding efficiency and reducing the total project cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic cross-sectional view of the layout of the ground negative pressure feeding system of the present invention;

[0022] Figure 2 A schematic structural diagram of the automatic feeding device of the ground negative pressure feeding system in the present invention.

[0023] The reference numerals in the figure are as follows: 1-water storage pump; 2-speed adjustable jet pump; 3-pipeline; 31-horizontal section; 32-bend section; 33-straight section; 4-first connecting valve; 41-valve stem; 5-graded sand and gravel aggregate; 6-hopper; 7-flow rate monitoring meter; 8-pressure monitoring meter; 9-pressure relief valve; 10-directional tunnel drilling casing; 101-first directional tunnel drilling casing; 102-second directional tunnel drilling casing; 11-directional tunnel drilling; 12-water gushing tunnel; 13-aggregate accumulation body; 14-second connecting valve; 15-baffle; 16-baffle bracket; 17-connecting rod. DETAILED DESCRIPTION

[0024] In this embodiment, graded sand and gravel aggregate is used to intercept and plug the water inrush tunnel. According to on-site measurements, graded sand and gravel aggregate with a porosity of 14% is selected, and the solid ratio of the graded sand and gravel aggregate is: fine sand (1-3 mm): small gravel (5-10 mm): medium gravel (10-30 mm): large gravel (30-50 mm) = 1:1:2:1. In some other embodiments, other sand and gravel with different particle sizes of 1 mm to 50 mm can also be used, and the solid ratio is determined according to the porosity of the graded sand and gravel aggregate.

[0025] like Figure 1The figure is a schematic cross-sectional view of the layout of the ground negative pressure feeding system in this embodiment. As can be seen from the figure, the ground negative pressure feeding system in this embodiment includes a water storage pump 1, a pipeline 3 and a directional tunnel drilling casing 10 which are sequentially connected and fluid-conductive; the first end of the pipeline 3 is conductively connected to the drainage port of the water storage pump 1, and the pipeline 3 is conductively connected to the first end of the directional tunnel drilling casing 10 through a second connecting valve 14 located at the second end of the pipeline 3. The pipeline 3 is divided into a horizontal section 31 parallel to the ground, a curved section 32 and a straight section 33 perpendicular to the ground. Along the direction from the first end to the second end of the pipeline 3, the horizontal section 31, the curved section 32 and the straight section 33 of the pipeline 3 are sequentially connected and fluidly connected. The pressure relief valve 9 is arranged on the straight section 33 of the pipeline 3. The discharge port of the hopper 6 is fluidly connected with the middle part of the horizontal section 31. The distance between the discharge port of the hopper 6 and the adjustable speed jet pump 2 is smaller than the distance between the discharge port of the hopper 6 and the water outlet end of the horizontal section 31. The distance between the discharge port of the hopper 6 and the adjustable speed jet pump 2 is small, which is conducive to rapid contact and The horizontal section 31 downstream of the discharge port of the hopper 6 is relatively long to impact graded sand and gravel aggregate 5, which is conducive to the full mixing of water flow and graded sand and gravel aggregate 5. In actual use, the horizontal section 31 can be arranged in the horizontal direction, or the horizontal section 31 gradually rises along the direction of water flow, and the angle between the horizontal section 31 and the horizontal plane is 0° to 5°. When the flow fluctuation of the adjustable speed jet pump 2 is not enough to push the graded sand and gravel aggregate 5, the graded sand and gravel aggregate 5 can slide along the pipeline to the pump port of the adjustable speed jet pump 2. When the flow is restored, the graded sand and gravel aggregate 5 can be quickly pushed to mix with the water flow again to avoid the accumulation of graded sand and gravel aggregate 5. The second end of the directional tunnel drilling casing 10 passes through the directional tunnel drilling 11 between the ground and the water gushing tunnel 12 and extends to the top plate of the water gushing tunnel 12, and the inner cavity of the directional tunnel drilling casing 10 is connected to the water gushing tunnel 12.

[0026] Along the first end of the pipeline 3 toward the second end of the pipeline 3, the pipeline 3 is sequentially installed with an adjustable speed jet pump 2, a hopper 6, a flow rate monitoring meter 7 for measuring the flow rate of the fluid in the pipeline 3, a pressure monitoring meter 8 for measuring the pressure in the pipeline 3, and a pressure relief valve 9. The discharge port at the lower end of the hopper 6 is connected to the middle fluid of the horizontal section 31 of the pipeline 3 through the first connecting valve 4.

[0027] In the pipeline 3, the graded sand and gravel aggregates 5 will be mixed with water to form a sand-carrying water flow. The adjustable speed jet pump 2 is used to control the speed of the water flow in the pipeline 3, so that the water flow carrying the sand and gravel aggregates flows at a uniform speed in the water delivery pipeline, that is, the flow rate of the sand-carrying water flow in the pipeline 3 can be adjusted by the adjustable speed jet pump 2. However, no matter how it is adjusted, the minimum speed of the sand-carrying water flow must be greater than or equal to the falling speed of the sand and gravel aggregates in still water.

[0028] In this embodiment, when using the graded sand and gravel aggregate with the above-mentioned solid phase ratio, the flow rate of the sand-carrying water flow is controlled at 165m / s. 3 / h~175m 3 / h, the implementation effect is ideal and pipe blockage is unlikely to occur in pipeline 3.

[0029] When the adjustable-speed jet pump 2 drives the water to flow in the pipeline 3, negative pressure is formed at the connection between the discharge port of the hopper 6 and the pipeline. At the same time, under the action of the deadweight of the graded sand and gravel aggregates, the graded sand and gravel aggregates are more easily sucked into the pipeline and flow forward with the water.

[0030] Furthermore, in order to automatically control the discharge volume of the hopper 6, an automatic feeding control device is used in the ground negative pressure feeding system in this embodiment, and the automatic feeding control device includes a baffle 15, a baffle bracket 16, a connecting rod 17 and a first connecting valve 4. The first connecting valve 4 in this embodiment is a gate valve, which includes a valve stem 41 and a gate connected to the second end of the valve stem 41; the first end of the baffle 15 extends into the tube cavity of the pipeline 3, and the plate surface of the baffle is perpendicular to the direction of water flow in the pipeline 3, the second end of the baffle 15 passes through the tube wall of the pipeline 3 and is hinged to the first end of the connecting rod 17 outside the tube cavity of the pipeline 3; the second end of the connecting rod 17 is hinged to the first end of the valve stem 41; the baffle bracket 16 is fixedly installed outside the tube wall of the pipeline 3, and the baffle bracket 16 is hinged to the middle part of the baffle 15, and the hinge axis of the baffle bracket 16 and the baffle 15 is perpendicular to the extension direction of the pipeline 3; the first connecting valve 4 is installed on the passage between the discharge port of the hopper 6 and the pipeline 3, and the gate of the first connecting valve 4 directly controls the on-off of the passage.

[0031] A sealing ring is provided at the position where the baffle 15 passes through the pipe wall of the pipeline 3, and the sealing ring is sleeved on the outer periphery of the baffle 15 to prevent the water flow in the pipeline 3 from leaking from the position where the baffle 15 passes through.

[0032] like Figure 2As shown, when the water flow in the pipeline 3 pushes the baffle 15, the baffle 15 rotates with the hinge axis between it and the baffle bracket 16 as the rotation axis, and with the help of the transmission effect of the connecting rod 17, the first end of the valve stem 41 of the first connecting valve 4 moves away from the hopper 6. At this time, the valve stem 41 "pulls out" the gate from the passage between the discharge port of the hopper 6 and the pipeline 3, and the discharge port of the hopper 6 is opened, and the discharge port of the hopper 6 is connected to the passage between the pipeline 3; when there is no water flow in the pipeline 3 to push the baffle 15, the passage between the discharge port of the hopper 6 and the pipeline 3 is in a closed state. In this way, the automation of the feeding of graded sand and gravel aggregates can be realized, that is, when the adjustable speed jet pump 2 is turned on and there is water flow in the pipeline 3, the discharge port of the hopper 6 is automatically opened, and the greater the water flow rate, the greater the opening degree of the first connecting valve, and the greater the feeding amount of graded sand and gravel aggregates 5.

[0033] The ground negative pressure feeding system mainly includes the following steps during installation and operation:

[0034] Step 1: Construction of ground directional tunnel drilling 11. The ground directional tunnel drilling 11 penetrates all the strata between the ground and the water inrush tunnel. During the construction of the ground directional tunnel drilling, the ground is used as the starting point for downward drilling, and the drilling end point is 1m deep into the bottom plate of the water inrush tunnel.

[0035] The buried depth of the water-gushing tunnel in this embodiment is 300m. The ground directional tunnel drilling structure is divided into two stages for opening and drilling during construction. A 311mm drill bit is used for the first stage of drilling, and the drilling is started from the ground to 70-80m underground (5-15m below the bedrock), that is, the hole depth of the first stage of drilling is 70-80m. After the drilling of the first stage of drilling is completed, a first directional tunnel drilling casing 101 with an outer diameter of 244.5mm is lowered into the borehole. A 216mm drill bit is used for direct tunnel drilling in the second stage of drilling, and the drilling is carried out to 1m below the bottom plate of the water-gushing tunnel 12. After the drilling of the second stage of drilling is completed, a second directional tunnel drilling casing 102 with an outer diameter of 177.8mm is lowered into the second stage of drilling, and the inner diameter of the first directional tunnel drilling casing 101 is larger than the inner diameter of the second directional tunnel drilling casing 10. In some other embodiments, the depth of the first section of the borehole may vary depending on the depth of the bedrock in the stratum. However, in general, the first section of the borehole should be drilled to 5 to 15 meters below the bedrock.

[0036] Step 2: Laying ground pipeline 3. Lay 16Mn wear-resistant seamless steel pipe with wall thickness t=8mm and inner diameter r=152mm in the ground feeding site. The overhead height of pipeline 3 is 0.5m (referring to the vertical distance between the horizontal section of pipeline 3 and the ground is 0.5m).

[0037] Step 3: Install the water storage pump 1 and the adjustable speed jet pump 2, connect the water outlet of the water storage pump 1 to the first end of the pipeline 3, and install the adjustable speed jet pump 2, the hopper 6, the flow rate monitoring meter 7, the pressure monitoring meter 8 and the pressure relief valve 9 on the pipeline 3. The discharge port of the hopper 6 is connected to the pipeline 3 through the first connecting valve 4. The flow rate monitoring meter 7 and the pressure monitoring meter are installed on the pipeline 3 on the downstream side of the hopper 6. The pressure relief valve 9 is installed on the straight pipe section at the second end of the pipeline 3.

[0038] Step 4: closing the discharge port of the hopper 6 and loading the graded sand and gravel aggregate 5 into the hopper 6;

[0039] Step 5: Perform initial debugging. Open the water storage pump 1, the adjustable speed jet pump 2, and the discharge port of the hopper 6. At this time, the water storage pump 1 draws water from the water source through the water suction port, and pumps water into the pipeline 3 through the discharge port. The graded sand and gravel aggregate 5 contained in the hopper 6 enters the pipeline 3 and mixes with the water in the pipeline 3 to form a sand-carrying water flow. Since the end of the pipeline 3 has not yet been connected to the directional tunnel drilling casing 10, the discharge of aggregate with the water flow can be observed at the outlet of the ground pipeline end, and the flow rate monitoring meter 7 and the pressure monitoring meter 8 are observed to be working properly. In case of abnormal conditions, they can be adjusted before the end of the pipeline 3 is connected to the directional tunnel drilling casing 10. After the initial debugging is completed, the flow rate of the sand-carrying water flow is relatively uniform, and the flow rate monitoring meter 7 and the pressure monitoring meter 8 are working normally.

[0040] Step 6: Connect the pipeline 3 with the directional tunnel drilling casing 10. In the case that the initial debugging is normal, the pipeline 3 and the directional tunnel drilling casing 10 are tightly connected by bolts through the second connecting valve 14.

[0041] Step 7: Perform mid-term debugging. Open the water storage pump 1, the adjustable speed jet pump 2, and the outlet of the hopper 6, and observe whether the flow rate monitoring meter 7 and the pressure monitoring meter 8 are working normally. After the flow rate of the sand-carrying water flow in the pipeline 3 and the directional tunnel drilling casing 10 is stable, open the pressure relief valve 9 and observe whether it has a pressure relief effect. If there is any abnormality, further adjustments can be made.

[0042] Step 8: Open the water storage pump 1, the adjustable speed jet pump 2, and the discharge port of the hopper 6, close the pressure relief valve 9, dynamically adjust the water flow rate of the adjustable speed jet pump 2 according to the values ​​of the flow rate monitoring table 7 and the pressure monitoring table 8, and implement ground directional tunnel drilling negative pressure feeding.

[0043] Step 9: After the feeding amount reaches the designed feeding amount and the pressure in the pipeline 3 rises to greater than 0MPa, stop the negative pressure feeding of the ground directional tunnel drilling. The designed feeding amount is approximately equal to the volume of the aggregate accumulation body 13, and the volume of the aggregate accumulation body 13 is estimated based on the cross-sectional size of the water-gushing tunnel. In actual application, the feeding progress is judged according to the consumption of the graded sand and gravel aggregate 5 in the hopper 6. When the feeding amount reaches the designed feeding amount and the indication of the pressure monitoring meter 8 rises from a negative value to a positive value, the water storage pump 1, the adjustable speed jet pump 2, and the hopper 6 discharge port can be closed, and the pressure relief valve 9 can be opened to stop the feeding operation.

[0044] During the feeding process, when the value of the pressure monitoring gauge 8 is 0 or a positive value, it indicates that the pipeline 3 and the directional tunnel drilling hole 11 are blocked. When the value of the pressure monitoring gauge 8 exceeds 1MPa, the pressure monitoring gauge 8 will emit an alarm flashing light. At this time, the water storage pump 1, the adjustable speed jet pump 2, and the hopper 6 discharge port should be closed, and the pressure relief valve 9 should be opened to block the pipe or the hole.

[0045] When the depth of the water-gushing tunnel is different, the sand-carrying water flow will be accelerated to different degrees after flowing into the straight pipe section 33 of the pipeline 3, and enter the water-gushing tunnel at a flow rate greater than that in the pipeline 3. Engineering tests show that the flow rate of the sand-carrying water flow when entering the water-gushing tunnel should be 1.3 to 2.0 times the flow rate of the gushing water in the tunnel. This is because when the flow rate of the sand-carrying water flow entering the water-gushing tunnel is too low, the gushing water in the tunnel may wash away the graded sand and gravel aggregates, making it difficult to form aggregate accumulations on the tunnel floor; and when the flow rate of the sand-carrying water flow entering the water-gushing tunnel is too high, the sand-carrying water flow will impact the tunnel floor with a greater force, easily dispersing the aggregate accumulations that have been formed.

[0046] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A ground negative pressure feeding system for blocking water inrush in deep buried tunnels, characterized in that: The invention comprises a pipeline (3), an adjustable speed jet pump (2), a directional tunnel drilling casing (10) and a hopper (6); a directional tunnel drilling hole (11) which is in communication with a water gushing tunnel (12) is provided on the ground; the second end of the directional tunnel drilling casing (10) is inserted into the directional tunnel drilling hole (11) and is in fluid communication with the water gushing tunnel (12); the adjustable speed jet pump (2) is arranged on the ground; the water outlet end of the adjustable speed jet pump (2) is connected to the first end of the pipeline (3); the second end of the pipeline (3) is connected to the directional tunnel drilling casing (11); 0); the discharge port of the hopper (6) is connected to and conducted with the pipeline (3), and the hopper (6) is filled with graded sand and gravel aggregate (5); the adjustable speed jet pump (2) supplies a high-speed water flow into the pipeline (3), and the graded sand and gravel aggregate (5) in the hopper (6) enters the pipeline (3) through the discharge port and is mixed with the high-speed water flow before entering the directional tunnel drilling casing (10), and the high-speed water flow drives the graded sand and gravel aggregate (5) into the water-gushing tunnel (12) to form an aggregate accumulation body (13).

2. The ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels according to claim 1 is characterized in that: The pipeline (3) is divided into a horizontal section (31) parallel to the ground, a curved pipe section (32) and a straight pipe section (33) perpendicular to the ground. Along the direction from the first end to the second end of the pipeline (3): the horizontal section (31), the curved pipe section (32) and the straight pipe section (33) are sequentially connected and fluidly connected; the discharge port of the hopper (6) is fluidly connected to the middle part of the horizontal section (31).

3. The ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels according to claim 2 is characterized in that: The ground negative pressure feeding system further comprises a pressure relief valve (9) arranged on the straight pipe section (33) of the pipeline (3).

4. The ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels according to claim 1 is characterized in that: The ground negative pressure feeding system further comprises a baffle (15), a baffle bracket (16), a connecting rod (17) and a first connecting valve (4); the first connecting valve (4) is a gate valve, the first connecting valve (4) comprises a valve stem (41) and a gate connected to the second end of the valve stem (41); the first end of the baffle (15) extends into the lumen of the pipeline (3), and the plate surface of the baffle is perpendicular to the direction of water flow in the pipeline (3); the second end of the baffle (15) passes through the wall of the pipeline (3) and is hinged to the first end of the connecting rod (17) outside the lumen of the pipeline (3); the second end of the connecting rod (17) is connected to the valve stem The first end of the pipe (41) is hinged; the baffle bracket (16) is fixedly mounted outside the pipe wall of the pipeline (3), and the baffle bracket (16) is hinged at the middle part of the baffle (15), and the hinge axis of the baffle bracket (16) and the baffle (15) is perpendicular to the extension direction of the pipeline (3); the first connecting valve (4) is mounted on the passage between the discharge port of the hopper (6) and the pipeline (3), and the gate of the first connecting valve (4) directly controls the opening and closing of the passage; when the water flow in the pipeline (3) pushes the baffle (15), the discharge port of the hopper (6) and the passage between the pipeline (3) are connected.

5. The ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels according to claim 1 is characterized in that: During the drilling construction of the directional tunnel drilling hole (11), the end thereof away from the ground is drilled to 1 m below the bottom plate of the water-gushing tunnel (12).

6. The ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels according to claim 5 is characterized in that: The directional tunnel boring casing (10) is divided into a first directional tunnel boring casing (101) and a second directional tunnel boring casing (102); the upper end of the first directional tunnel boring casing (101) is conductively connected to the pipeline (3), the lower end of the first directional tunnel boring casing (101) is conductively connected to the upper end of the second directional tunnel boring casing (102), and the inner diameter of the first directional tunnel boring casing (101) is larger than the inner diameter of the second directional tunnel boring casing (102); the first directional tunnel boring casing (101) extends vertically downward from the ground to 5 to 15 meters below the bedrock in the stratum, and the lower end of the second directional tunnel boring casing (102) is flush with the top plate of the water-gushing tunnel (12).

7. The ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels according to claim 1 is characterized in that: When the ground negative pressure feeding system is in operation, the graded sand and gravel aggregate (5) contained in the hopper (6) enters the pipeline (3) and mixes with the water in the pipeline (3) to form a sand-carrying water flow; the flow rate of the sand-carrying water flow in the pipeline (3) is greater than or equal to the free falling rate of the graded sand and gravel aggregate (5) in still water.

8. The ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels according to claim 7, characterized in that: When the sand-carrying water flow enters the water gushing tunnel, the flow velocity of the sand-carrying water flow is 1.3 to 2.0 times the flow velocity of the gushing water in the water gushing tunnel (12).

9. The ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels according to claim 1, characterized in that: The ground negative pressure feeding system further comprises a flow rate monitoring meter (7) and a pressure monitoring meter (8) which are arranged in sequence along the first end of the pipeline (3) in the direction toward the second end of the pipeline (3), and the flow rate monitoring meter (7) is arranged on the pipeline on the downstream side of the hopper (6).

10. The ground negative pressure feeding system for intercepting and plugging water inrush in deep buried tunnels according to claim 1, characterized in that: The graded sand and gravel aggregate (5) is a mixture of sand and gravel with a particle size distribution between 1 mm and 50 mm and containing a plurality of different particle sizes, and the void ratio of the graded sand and gravel aggregate (5) is 10% to 20%.

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