Construction method for hydraulic high-gas tunnel

Abstract

The invention relates to the technical field of tunnel construction, and particularly discloses a hydraulic high-gas tunnel construction method, which comprises the following steps of: constructing an advanced detection hole in a tunnel, measuring the gas pressure in the advanced detection hole and the gas emission amount of the advanced detection hole, and when the gas pressure is greater than 0.15 MPa or the gas emission amount is greater than 4L / min, starting the advanced detection hole; gas is pumped and discharged through the gas pumping and discharging device, the gas pumping and discharging device comprises a framework, a filter barrel is detachably arranged in the framework and comprises a plurality of circular rings, each circular ring can slide in the axial direction of the framework, and a flexible metal filter screen is fixedly connected between every two adjacent circular rings. The framework is installed in the advanced detection hole, collapse of the advanced detection hole cannot be caused in the gas extraction process, the filter barrel is arranged in the framework, soil is filtered through the filter barrel and prevented from entering the gas extraction pipe, meanwhile, the inclined anchor rod is arranged at the tail end of the framework, the inclined anchor rod is inserted into a geological layer, and the gas extraction efficiency is improved. And the framework and surrounding soil form a whole.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, in particular to a hydraulic high-gas tunnel construction method. Background Art

[0002] As China's water conservancy infrastructure continues to improve, the use of deep, long, and dense hydraulic tunnels is becoming increasingly widespread, leading to more complex geological conditions. This is particularly true in areas rich in coal seams and high levels of gas. Gas is a colorless, odorless, non-toxic gas primarily composed of methane and ethylene. Gas is colorless, odorless, non-toxic, and lighter than air, easily accumulating at the top of tunnels. It has high permeability and diffuses rapidly. Excessive gas concentrations can significantly reduce the oxygen content in the air, causing suffocation. While highly flammable, it is not self-igniting. Under certain conditions, it can ignite or explode upon contact with a fire source, potentially causing engineering accidents.

[0003] Therefore, when constructing a tunnel in a high-gas area, it is necessary to first detect the gas content ahead. When the gas content is too high, the gas needs to be extracted. The existing technology for extracting gas from a gas tunnel involves first drilling an extraction hole, inserting an extraction pipe into the hole, and sealing the hole. The gas is then extracted out through the extraction pipe. During the extraction process, the extraction hole is always under negative pressure, which may cause the extraction hole to collapse during the gas extraction process. In addition, the soil in the extraction hole can easily enter the extraction pipe, blocking the pipe and affecting the gas extraction effect. Summary of the Invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a hydraulic high-gas tunnel construction method.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for constructing a hydraulic high-gas tunnel involves constructing a 40m advance detection hole in the tunnel, measuring the gas pressure in the advance detection hole and the gas outflow rate of the advance detection hole. When the gas pressure is greater than 0.15MPa or the gas outflow rate is greater than 4L / min, gas is extracted through a gas extraction device. After the gas extraction is completed, the advance detection hole is filled with grouting and cured. After the curing is completed, the tunnel is excavated.

[0007] The gas extraction device includes a frame, in which a filter barrel is detachably arranged. The filter barrel includes a plurality of rings, each of which can slide axially along the frame, and a flexible metal filter mesh is fixedly connected between two adjacent rings.

[0008] Preferably, one side of the frame is detachably connected to a sealing plate, and a gas extraction pipe is provided on the sealing plate.

[0009] Preferably, the skeleton includes two base rings, two groups of columns are fixedly connected between the two base rings, the two groups of columns are staggered and spaced one by one, and a plurality of arc-shaped support rods are fixedly connected between two adjacent columns.

[0010] Preferably, a guide groove is provided on one side of each group of columns, and a group of guide blocks are fixedly connected to each ring, and the guide blocks slide in the guide groove in a one-to-one correspondence.

[0011] Preferably, a slurry box is fixedly connected to the circular ring near the bottom of the frame, and a plurality of through holes are provided on the slurry box. A grouting pipe is provided on one side of the slurry box. The grouting pipe passes through each circular ring in turn and extends from the central hole of the sealing plate to the outside of the sealing plate.

[0012] Preferably, a plurality of mounting grooves are provided on one side of the other group of columns, a clearance hole penetrating the column is provided on one side of the mounting groove, and a reinforcement device is hingedly connected in the mounting groove via a first spring hinge.

[0013] Preferably, the reinforcement device includes a reinforcement block, which rotates in the installation groove through a first spring hinge. A storage hole is provided on one side of the reinforcement block, and a plug rod is slidably connected in the storage hole. One end of the plug rod is fixedly connected to the push rod. An avoidance hole that passes through the reinforcement block is provided at the bottom of the storage hole. The push rod passes through the avoidance hole, and one end of the push rod is fixedly connected to the touch ball.

[0014] Preferably, a clearance groove is provided on one side of the reinforcement block, and the touch ball can enter the clearance groove.

[0015] Preferably, an avoidance groove is provided at a corner of the reinforcement block, and the contact rod is rotatably connected in the avoidance groove through a second spring hinge.

[0016] Preferably, the bottom of the skeleton is slidably connected to a plurality of oblique anchor rods.

[0017] The beneficial effects of the present invention are as follows: the present invention installs a skeleton in the advance detection hole, so that the advance detection hole will not collapse during the gas extraction process; a filter barrel is set in the skeleton, and the soil is filtered through the filter barrel to prevent the soil from entering the gas extraction pipe; at the same time, an inclined anchor rod is set at the end of the skeleton, and the inclined anchor rod is inserted into the geological layer to form a whole with the skeleton and the surrounding soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram showing the configuration of the gas extraction device of the present invention;

[0019] Figure 2 This is the basic structural diagram of the gas extraction device;

[0020] Figure 3 This is the basic structure diagram of the filter barrel;

[0021] Figure 4 It is the usage status diagram of the filter barrel;

[0022] Figure 5 This is the first usage state diagram of the reinforcement device;

[0023] Figure 6 This is the second usage state diagram of the reinforcement device;

[0024] Figure 7 This is the third usage state diagram of the reinforcement device;

[0025] Figure 8 It is a basic structural diagram of the reinforcement device. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] Example 1

[0028] like Figure 1-8 As shown, a hydraulic high-gas tunnel construction method of this embodiment constructs a 40m advance detection hole in the tunnel, measures the gas pressure in the advance detection hole and the gas outflow of the advance detection hole, and when the gas pressure is greater than 0.15MPa or the gas outflow is greater than 4L / min, the gas is extracted by the gas extraction device 200. After the gas extraction is completed, the advance detection hole is grouting-filled and cured, and the tunnel is excavated after the curing is completed.

[0029] The gas extraction device 200 comprises a frame 1 comprising two base rings 11. Two sets of columns 13 are fixedly connected between the two base rings 11. In this embodiment, each set of columns 13 comprises four columns, and the four columns 13 in the two sets are spaced and staggered. Multiple curved support rods 14 are fixedly connected between adjacent columns 13. The curvature of the curved support rods 14 matches the diameter of the advance detection hole. A sealing plate 15 is removably connected to one side of the frame 1, and a gas extraction pipe 16 is mounted on the sealing plate 15. The sealing plate 15 is removably connected to the base rings 11. The method of removable connection in this embodiment is conventional and will not be further described here.

[0030] In this embodiment, when extracting gas, the skeleton 1 is first inserted into the advance detection hole, and the advance detection hole is sealed by the sealing plate 15. In this way, the skeleton 1 can support and protect the advance detection hole to prevent the collapse of the advance detection hole during the gas extraction process. The bottom of the skeleton 1 is slidably connected to multiple inclined anchor rods 10. Specifically, a "cross"-shaped mounting frame is set in the base ring 11, and a mounting hole is set on the mounting frame. The inclined anchor rod 10 slides in the mounting hole. After the skeleton 1 is placed in the advance detection hole, the inclined anchor rod 10 is pushed. The inclined anchor rod can be inserted into the surrounding soil. After the gas extraction is completed, the advance detection hole is grouting backfilled. The skeleton 1 and the inclined anchor rod form a whole with the surrounding soil, and the backfill reinforcement effect is significantly improved. In this way, it is strong and reliable when excavating the tunnel in the later stage, and it is not easy to cause the collapse of the tunnel.

[0031] When extracting gas, in order to prevent the soil in the advance detection hole from entering the gas extraction pipe 16 and causing blockage, a filter barrel 2 is detachably provided in the skeleton 1. After the gas extraction is completed, the filter barrel 2 needs to be removed. If it is not removed, the filter barrel 2 will block the mortar phase, and the cement mortar will not easily enter the surrounding soil layer. In this embodiment, the filter barrel 2 includes a plurality of rings 21, one side of which is provided with a guide groove, and each ring 21 is fixedly connected to a group of guide blocks 23, and the guide blocks 23 slide in the guide groove one by one. In this way, each ring 21 can slide axially along the skeleton 1, and a flexible metal filter screen 22 is fixedly connected between two adjacent rings 21. This not only prevents the soil from being extracted, but also provides auxiliary support to the skeleton through the rings 21. In order to facilitate the grouting backfilling of the advance detection hole after the gas extraction is completed, a slurry box 3 is fixedly connected to the circular ring 21 near the bottom of the skeleton 1. The slurry box 3 is provided with a plurality of through holes. A grouting pipe 33 is provided on one side of the slurry box 3. The grouting pipe 33 passes through each circular ring 21 in turn and extends from the center hole of the sealing plate 15 to the outside of the sealing plate 15. When the filter barrel 2 is placed into the skeleton 1, the inclined anchor rod 10 at the end of the skeleton 1 can be squeezed through the slurry box 3, so that the inclined anchor rod 10 is inserted into the soil layer at the front end. After the gas extraction is completed, when the filter barrel 2 is taken out, the slurry box 3 also moves outward, so that grouting is slowly carried out from the bottom of the advance detection hole upward. During the grouting process, the slurry can be shielded by the slurry box 3 to prevent a large amount of slurry from being lost from the advance detection hole.

[0032] To further backfill the advanced exploration borehole and reinforce the surrounding geological formations, multiple mounting slots 131 are provided on one side of the other set of columns 13. A clearance hole 132 is provided on one side of each mounting slot 131, extending through the column 13. A reinforcement device 4 is housed within each mounting slot 131. This reinforcement device 4 comprises a reinforcement block 41, which rotates within the mounting slot 131 via a first spring hinge 40. A storage hole 42 is provided on one side of the reinforcement block 41, into which a plunger 42 is slidably connected. One end of the plunger 42 is fixedly connected to a push rod 44. The bottom of the storage hole 42 is provided with a clearance hole extending through the reinforcement block 41. The push rod 44 passes through the clearance hole and is fixedly connected to a contact ball 45 at one end. A clearance slot 46 is provided on one side of the reinforcement block 41, into which the contact ball 45 can enter. When a thrust is applied to the push rod 44, the push rod 44 pushes the insertion rod 42 through the clearance hole 132 and into the surrounding soil. A relief groove 47 is provided at the corner of the reinforcement block 41. The relief groove 47 is connected to the contact rod 49 through the second spring hinge 48. When the second spring hinge 48 is in a free state, the contact rod 49 is parallel to the push rod 44. Figure 5-Figure 7 , the first spring hinge 40 is in a free state and when there is no other external force, the push rod 44 in the reinforcement device 4 is coaxially arranged with the clearance hole 132. Figure 5 and Figure 6 When the filter barrel 2 is inserted into the frame 1, the slurry box 3 first contacts the contact rod 49 extending from the reinforcement device 4. As the slurry box 3 descends, the reinforcement device 4 rotates around the first spring hinge 40, thereby rotating into the installation groove 131. A limit rod 133 is installed in the installation groove 131. When the reinforcement device 4 contacts the limit rod 133, the push rod 44 is exactly coaxial with the clearance hole 132.

[0033] When the reinforcement device 4 is completely in the installation groove 131 , the position of the ring 21 corresponds exactly to the reinforcement device 4 . At this time, under the extrusion force of the ring 21 , the reinforcement device 4 is always in the installation groove 131 . After the gas extraction is complete and the filter barrel 2 is removed, the ring 21 sequentially leaves the reinforcement device 4. After the reinforcement device 4 loses the protection of the ring 21, the first spring hinge 40 causes the reinforcement device 4 to pop out of the mounting slot 131. At this point, the push rod 44 is coaxially arranged with the clearance hole 132. When the slurry box 3 passes through the push rod 44, the conical surface 31 at the upper end of the slurry box 3 contacts the touch ball 45. The slurry box 3 generates a thrust on the touch ball 45, causing the push rod 44 and the insertion rod 43 to move together. This allows the insertion rod 43 to pass through the clearance hole 132 and be inserted into the surrounding soil, thereby reinforcing the skeleton 1 and forming a whole with the surrounding soil. This significantly increases the strength of the surrounding geological layer after grouting reinforcement, making it less likely to collapse or deform during tunnel excavation. When the slurry box 3 passes through the touch rod 49, the touch rod 49 flips over and enters the mounting slot 131, without affecting the movement of the slurry box 3.

Claims

1. A hydraulic high-gas tunnel construction method, characterized in that: An advance detection hole is constructed in the tunnel, and the gas pressure in the advance detection hole and the gas outflow rate of the advance detection hole are measured. When the gas pressure is greater than 0.15 MPa or the gas outflow rate is greater than 4 L / min, the gas is extracted and drained through a gas extraction device (200). After the gas extraction is completed, the advance detection hole is grout-filled and cured. After the curing is completed, the tunnel is excavated; The gas extraction device (200) comprises a frame (1), a filter barrel (2) is detachably arranged in the frame (1), and the filter barrel (2) comprises a plurality of rings (21), each of which is capable of sliding axially along the frame (1), and a flexible metal filter screen (22) is fixedly connected between two adjacent rings (21).

2. A hydraulic high-gas tunnel construction method according to claim 1, characterized in that: One side of the frame (1) is detachably connected to a sealing plate (15), and a gas extraction pipe (16) is provided on the sealing plate (15).

3. A hydraulic high-gas tunnel construction method according to claim 1, characterized in that: The skeleton (1) comprises two base rings (11), two groups of columns (13) are fixedly connected between the two base rings (11), the two groups of columns (13) are staggered and arranged one by one, and a plurality of arc-shaped support rods (14) are fixedly connected between two adjacent columns (13).

4. A hydraulic high-gas tunnel construction method according to claim 3, characterized in that: One side of one group of upright posts (13) is provided with a guide groove, and each of the circular rings (21) is fixedly connected to a group of guide blocks (23), and the guide blocks (23) slide in the guide groove in a one-to-one correspondence.

5. A hydraulic high-gas tunnel construction method according to claim 3, characterized in that: A slurry box (3) is fixedly connected to a circular ring (21) near the bottom of the frame (1), and a plurality of through holes are provided on the slurry box (3). A grouting pipe (33) is provided on one side of the slurry box (3), and the grouting pipe (33) passes through each circular ring (21) in sequence and extends from the central hole of the sealing plate (15) to the outside of the sealing plate (15).

6. A hydraulic high-gas tunnel construction method according to claim 5, characterized in that: A plurality of mounting grooves (131) are provided on one side of the other group of upright posts (13), and a clearance hole (132) penetrating the upright posts (13) is provided on one side of the mounting grooves (131). The reinforcement device (4) is hinged in the mounting grooves (131) via a first spring hinge (40).

7. A hydraulic high-gas tunnel construction method according to claim 6, characterized in that: The reinforcement device (4) includes a reinforcement block (41), the reinforcement block (41) rotates in the installation groove (131) through a first spring hinge (40), a storage hole (42) is provided on one side of the reinforcement block (41), an insertion rod (42) is slidably connected in the storage hole (42), one end of the insertion rod (42) is fixedly connected to a push rod (44), a avoidance hole penetrating the reinforcement block (41) is provided at the bottom of the storage hole (42), the push rod (44) passes through the avoidance hole, and one end of the push rod (44) is fixedly connected to a contact ball (45).

8. A hydraulic high-gas tunnel construction method according to claim 7, characterized in that: A clearance groove (46) is provided on one side of the reinforcement block (41), and the touch ball (45) can enter the clearance groove (46).

9. A hydraulic high-gas tunnel construction method according to claim 7, characterized in that: An avoidance groove (47) is provided at a corner of the reinforcement block (41), and a contact rod (49) is rotatably connected in the avoidance groove (47) via a second spring hinge (48).

10. A hydraulic high-gas tunnel construction method according to claim 1, characterized in that: The bottom of the skeleton (1) is slidably connected to a plurality of oblique anchor rods (10).

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