A treatment method for mud gushing in a bidirectional separation type tunnel crossing a confined water capsule formation

Abstract

The application discloses a treatment method for mud gushing in a tunnel pressure-bearing water capsule stratum in a bidirectional separation mode, and belongs to the technical field of tunnel mud gushing prevention and treatment. Temporary arch protection, mud retaining walls, mud gushing body pressure retaining, curtain grouting, drainage pressure releasing holes, and the synergistic effect of the curtain grouting and the drainage pressure releasing are applied to treat the pressure-bearing water capsule stratum. The method can treat the mud gushing in the tunnel containing the pressure-bearing water capsule, effectively solves the difficulty in grouting treatment caused by high water pressure, and comprehensively treats the mud gushing disaster in multiple aspects.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of tunnel mud gushing prevention and treatment, and particularly relates to a treatment method for mud gushing in a tunnel passing through a confined water pocket stratum in a bidirectional separation mode. BACKGROUND

[0002] When a tunnel passes through a fault fracture zone, strongly weathered sandstone and other poor geological structures with characteristics of softness, fragmentation and high water pressure, the stratum is prone to contain a confined water pocket, thereby causing mud gushing disasters. After a disaster occurs when a tunnel passes through a confined water pocket, a large amount of silt is accumulated in the tunnel, so that the surrounding rock of the working face temporarily maintains balance. Once the silt is removed, the working face loses balance and is prone to mud gushing again, threatening the personal safety of engineering personnel. In addition, since the gushing mud is mostly accumulated in the built section of the tunnel, when a grouting method is used for treatment, due to the large disturbance range of the gushing mud on the stratum, curtain grouting cannot be truly realized, and the weak treatment area left behind becomes a safety hazard for tunnel construction, and a relatively high grouting pressure can cause secondary damage to the existing lining and disturbed stratum. Therefore, how to more efficiently treat the gushing mud when a tunnel passes through a confined water pocket has become a difficult problem to be solved. SUMMARY

[0003] To solve the above problems, the present application provides a treatment method for mud gushing in a tunnel passing through a confined water pocket stratum in a bidirectional separation mode, which can effectively treat the disturbed surrounding rock, protect the damage of grouting pressure to the built tunnel structure, treat the disaster from multiple aspects, and ensure the safety of tunnel construction.

[0004] Specifically, a treatment method for mud gushing in a tunnel passing through a confined water pocket stratum in a bidirectional separation mode, comprising the following steps:

[0005] Step 1: arch protection

[0006] A temporary arch is constructed from the end boundary position of the silt accumulation body to the direction away from the working face, the arch is attached to the built lining, and the arch is provided with a plurality of bays, and the adjacent two bays are connected by steel bars to form a whole;

[0007] The arch is fixedly connected with a pad at the arch foot, and the pad is fixedly connected with the tunnel inverted arch; a plurality of bays of arches are arranged in parallel along the longitudinal direction of the tunnel at an interval, and the farthest distance from the working face is 20 m;

[0008] The first two bays of arches close to the working face are each provided with a plurality of first transverse steel bars arranged at an interval in the height direction on the inner walls of the two sides of each bay of arches, and a plurality of first vertical steel bars are arranged at an interval in the width direction of the tunnel on the ground where each bay of arches is located;

[0009] Step 2: construction of silt retaining wall

[0010] A mud retaining wall with a narrow top and a wide bottom is constructed, the bottom of the mud retaining wall is connected with the first vertical steel bars on the ground, and the side is connected with the first horizontal steel bars on the arch;

[0011] Step three: construction of the pressure retaining wall

[0012] A pressure retaining wall is constructed on the surface of the silt accumulation body, one end of the pressure retaining wall is connected with the constructed lining, and the other end is fixedly connected with the mud retaining wall; a plurality of rows of grouting holes arranged in a plum blossom pattern are constructed from top to bottom on the surface of the pressure retaining wall into the silt accumulation body, and the silt accumulation body is grouted and reinforced;

[0013] The specific connection method of the mud retaining wall and the pressure retaining wall is that a platform is constructed on the mud retaining wall near the top and directed to the tunnel face; second horizontal steel bars are arranged on the mud retaining wall and directed to the platform, second vertical steel bars are arranged on the platform and directed to the tunnel vault, and the second horizontal steel bars and the second vertical steel bars are fixedly connected by intersecting; one end of the pressure retaining wall is fixedly connected on the platform by overlapping the second horizontal steel bars and the second vertical steel bars.

[0014] Step four: curtain grouting

[0015] First grouting holes and second grouting holes are constructed between the primary support steel arches within a range of ±50° of the tunnel centerline, and small pipe grouting is performed; a plurality of curtain grouting holes are constructed from the surface of the pressure retaining wall through the silt accumulation body and covering the front of the mud gushing port, and curtain grouting is performed;

[0016] The angle between the first grouting hole and the horizontal plane is 65°, and the angle between the second grouting hole and the horizontal plane is 45°; the reinforcing length of the first grouting hole and the second grouting hole along the longitudinal direction of the tunnel is not more than 12m; the grouting pressure of the first grouting hole and the second grouting hole is not more than 0.5MPa; the reinforcing length of the curtain grouting hole along the longitudinal direction of the tunnel is not more than 30m; the curtain grouting hole is grouted by pressure grouting method, and the maximum grouting pressure is not more than 6MPa.

[0017] Step five: construction of water drainage pressure release holes

[0018] A plurality of water drainage pressure release holes are constructed on the side wall at the position of the opposite tunnel corresponding to the mud gushing port, the water drainage pressure release holes pass through the partition wall between the two tunnels and extend into the pressure-bearing water bag for water drainage, a geological casing for hole protection and grouting plugging is arranged in each water drainage pressure release hole, and a valve is installed at the end of the geological casing;

[0019] The plurality of water drainage pressure release holes are arranged in parallel and at intervals within a range of 4m on both sides of the mud gushing port as the center;

[0020] During the water drainage process of the water drainage pressure release holes, the amount of silt in each water drainage pressure release hole is counted, and for each water drainage pressure release hole, if the amount of silt carried exceeds 2m3 / h, after continuous hydrophobicity for more than 10 days, closing the valve on the hydrophobic pressure relief hole, and opening the hydrophobic pressure relief hole farthest from the hydrophobic pressure relief hole;

[0021] When the amount of silt in each hydrophobic pressure relief hole does not exceed 2m 3 / h, but the total amount of silt of all hydrophobic pressure relief holes exceeds 600m 3 After 3 days of slurry consolidation, open all the valves to continue hydrophobicity.

[0022] Step six: curtain grouting and hydrophobic pressure relief are cooperated

[0023] The curtain grouting and the hydrophobic pressure relief hole hydrophobicity are simultaneously carried out, when the slurry appears in the hydrophobic pressure relief hole, the valve is closed, the hydrophobic pressure relief is stopped, and each hydrophobic pressure relief hole is sequentially grouted and sealed, and the hydrophobicity is permanently stopped; after the curtain grouting is finished, the arch protection, the silt retaining wall and the pressure block are removed, and the tunnel construction is continued after dredging.

[0024] The method has the advantages that: the method can comprehensively treat the tunnel with a bidirectional separation type and a pressure-bearing water bag after mud gushing, effectively avoids the influence of the pressure-bearing water bag on subsequent treatment work and the built lining after mud gushing disaster, and effectively solves the problem of high water pressure in grouting treatment. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a tunnel front view for treating mud gushing described in embodiment 1 of the application;

[0026] Figure 2 It is a tunnel profile view for treating mud gushing described in embodiment 1 of the application;

[0027] Figure 3 It is a plane view for treating mud gushing described in embodiment 1 of the application. DETAILED DESCRIPTION

[0028] The terms used in the present application have the meanings generally understood by those of ordinary skill in the art, unless otherwise specified.

[0029] The present application will be further described in detail below with specific examples and by referring to the data. The following examples are only for illustrating the present application, and do not limit the scope of the present application in any way.

[0030] Embodiment 1

[0031] A treatment method for mud gushing of a bidirectional separation type tunnel passing through a pressure-bearing water bag stratum, comprising the following steps:

[0032] Step one: arch protection is made

[0033] As shown in Figure 1 , a number of temporary arches 1 are made at the end boundary position of the silt accumulation body 21 away from the working face, the arches 1 are attached to the built lining 2, and the two are consistent in curvature, and the two adjacent arches 1 are connected into a whole through the setting of the steel bars 9;

[0034] The first two arches 1 close to the working face are each provided with a plurality of first horizontal steel bars 10 arranged in the height direction on the inner walls of the two sides of each arch 1, and a plurality of first vertical steel bars 11 are arranged in the tunnel width direction on the ground 8 where each arch 1 is located;

[0035] Step two: construction of the silt retaining wall

[0036] As shown in Figure 2 , a silt retaining wall 12 is made which is narrow at the top and wide at the bottom, and the height of the silt retaining wall 12 is 3-3.5m;

[0037] As shown in Figure 1 , the bottom of the silt retaining wall 12 is connected with the first vertical steel bars 11 on the ground 8, and the side surface is connected with the first horizontal steel bars 10 on the arch 1; the bottom of the silt retaining wall 12 is provided with a drain pipe 16. Preferably, the side close to the working face of the silt retaining wall 12 in the embodiment is a vertical surface, and the side away from the working face is inclined towards the working face.

[0038] Step three: construction of the silt accumulation body pressure retaining

[0039] As shown in Figure 2 , a pressure retaining 17 is made on the surface of the silt accumulation body 21, one end of the pressure retaining 17 is connected with the built lining 2, and the other end is fixedly connected with the silt retaining wall 12; a plurality of rows of grouting holes 19 arranged in a quincunx pattern are made on the surface of the pressure retaining 17 from top to bottom into the silt accumulation body 21, and the grouting holes 19 are grouted to reinforce the silt accumulation body 21; Figure 1

[0040] Specifically, in order to better realize the fixed connection of the pressure retaining 17 and the silt retaining wall 12, a platform 13 is made on the silt retaining wall 12 close to the top towards the working face, the silt retaining wall 12 is provided with a second horizontal steel bar 14 extending towards the platform 13, the platform 13 is provided with a second vertical steel bar 15 extending towards the tunnel arch top, and the second horizontal steel bar 14 and the second vertical steel bar 15 are crosswise fixedly connected; one end of the pressure retaining 17 connected with the silt retaining wall 12 is fixedly connected on the platform 13 through the second horizontal steel bar 14 and the second vertical steel bar 15.

[0041] Step four: curtain grouting

[0042] As shown in Figure 1 and Figure 2 ​As shown, firstly, a first grouting hole 22 and a second grouting hole 23 are constructed between the initial support steel arch frames within a ±50° range of the tunnel centerline for small-diameter grouting. Specifically, the angle between the first grouting hole 22 and the horizontal plane is 65°, the angle between the second grouting hole 23 and the horizontal plane is 45°, the reinforcement length of the first grouting hole 22 and the second grouting hole 23 along the longitudinal direction of the tunnel does not exceed 12m, and the grouting pressure of the first grouting hole 22 and the second grouting hole 23 does not exceed 0.5MPa.

[0043] Then, several curtain grouting holes 24 are made from the surface of the retaining wall 17, which pass through the silt accumulation body 21 and cover the front of the mud inlet 25, for curtain grouting. The curtain grouting holes 24 avoid the existing grouting holes 19 when drilling. The reinforcement length of the curtain grouting holes 24 along the longitudinal direction of the tunnel does not exceed 30m. The curtain grouting holes 24 are grouted by pressure grouting method, and the grouting pressure does not exceed 6MPa.

[0044] Step 5: Construction of hydrophobic pressure relief holes

[0045] like Figure 3 As shown, several drainage and pressure relief holes 27 are constructed on the sidewall 26 of the opposite tunnel position corresponding to the mud inlet 25. The drainage and pressure relief holes 27 are arranged in parallel at intervals within a range extending 4m to both sides of the mud inlet 25 as the center. The drainage and pressure relief holes 27 pass through the partition wall between the two tunnels and extend into the interior of the pressure-bearing water bladder 28. Each drainage and pressure relief hole 27 is equipped with a geological casing, and a valve is installed at the end of the geological casing.

[0046] It should be noted that during the drainage process of the hydrophobic pressure relief holes 27, the amount of sediment carried by each hydrophobic pressure relief hole 27 should be counted. For holes carrying more than 2m of sediment... 3 After continuously draining water through the pore at a rate of / h for more than 10 days, close the valve of that pore and open the pore furthest from it, followed by the pore 27, and so on. This process continues until the sediment load in each pore does not exceed 2m³. 3 / h, but the total sediment volume of all holes exceeds 600m³. 3 Afterwards, close all valves to perform grouting; after the grout has solidified for 3 days, open all valves to continue drainage.

[0047] Step Six: Curtain grouting and hydrophobic pressure relief are carried out in tandem.

[0048] The curtain grouting and the drainage process of the drainage and pressure relief holes 27 are carried out simultaneously. After the grout appears in the drainage and pressure relief holes 27, the grouting channel and the water inflow channel are connected. The valves on each drainage and pressure relief hole 27 are closed to stop drainage and pressure relief. Grouting is carried out on each drainage and pressure relief hole 27 in sequence to permanently stop drainage. After the curtain grouting is completed and the treatment effect is found to be good, the arch support 1, mud retaining wall 12 and pressure block 17 are removed. After dredging, tunnel construction continues.

[0049] Example 2

[0050] The method in Example 1 is applied to the tunnel fault mud gushing large confined water pocket treatment in Lianhuazhongjia Mountain Tunnel area, including the following steps:

[0051] Step one: arch protection construction

[0052] As shown in Figure 1 , several temporary arches 1 are constructed from the end boundary position of the silt accumulation body 21 to the direction away from the working face, the arches 1 are I-beams, the curvature of the arches 1 is consistent with and fits the curvature of the lining 2, the arches 1 are in close to zero pressure contact with the lining 2, a pad plate 4 with a size of 30cm*50cm is welded at the arch foot 3 of the arches 1, four φ25 high-strength bolts 6 are used to pass through the pad plate 4 and enter the inverted arch 7, the entering depth of the high-strength bolts 6 below the ground 8 is 60cm, and the length above the ground 8 is 40cm.

[0053] The several arches 1 are parallelly arranged at a longitudinal interval of 50cm along the tunnel, and the farthest distance from the working face is 20m, and the adjacent two arches 1 are connected into a whole through the steel bars 9.

[0054] The first two arches 1 close to the working face are each provided with a plurality of first transverse steel bars 10 arranged at intervals in the height direction on the inner walls of the two sides of each arch 1, and a plurality of first vertical steel bars 11 are arranged at intervals in the tunnel width direction on the ground 8 where each arch 1 is located.

[0055] Step two: mud retaining wall construction

[0056] As shown in Figure 2 , a mud retaining wall 12 with a narrow top and a wide bottom is constructed, the bottom of the mud retaining wall 12 is connected with the first vertical steel bars 11 on the ground 8, and the side surface is connected with the first transverse steel bars 10 on the arches 1; the bottom of the mud retaining wall 12 is reserved with a drain pipe 16.

[0057] In this embodiment, the retaining wall 12 is poured with concrete of strength grade C25, the first transverse steel bars 10 are arranged in four rows with two steel bars in each row on the inner wall of each arch 1, and the ends of the first transverse steel bars 10 are welded to the inner wall of the I-shaped steel arch 1; the distance between the two adjacent first vertical steel bars 11 in each arch 1 is 70 cm, the first vertical steel bars 11 have a depth of 60 cm below the ground 8 and a length of 40 cm above the ground 8; the parameters of the first transverse steel bars 10 and the first vertical steel bars 11 are both φ18, and the ends of the steel bars extending into the concrete are in the shape of hooks; the upper width of the retaining wall 12 is 1 m, the lower width is 3 m, and the height is 3 m; a DN40 drainage pipe 16 is reserved at the lower left of the retaining wall 12 in the direction facing the tunnel, the drainage pipe on the inner side of the retaining wall 12 is wrapped with geotextile, and the drainage pipe on the outer side is provided with a valve.

[0058] Step three: construction of the mud accumulation body pressure retaining wall

[0059] As shown in Figure 2 , first, the retaining wall 12 is constructed with a rectangular platform 13 at a position 20 cm below the top in the direction of the working face, the platform has a height of 30 cm and a length of 40 cm extending out of the retaining wall 12, the retaining wall 12 is provided with second transverse steel bars 14 extending in the direction of the platform 13, the platform 13 is provided with second vertical steel bars 15 extending in the direction of the tunnel vault, and the second transverse steel bars 14 and the second vertical steel bars 15 are fixedly connected in cross shape.

[0060] The pressure retaining wall 17 is constructed on the surface of the mud accumulation body 21 by using sprayed concrete, and has a thickness of 20 cm, one end of the pressure retaining wall 17 is connected with the built lining 2, the concrete thickness is increased at the tunnel vault 18, and the other end of the pressure retaining wall 17 is lapped on the platform 13 through the second transverse steel bars 14 and the second vertical steel bars 15 and is fixedly connected with the retaining wall 12, so as to form an integral whole.

[0061] As shown in Figure 1 and Figure 2 , three rows of grouting holes 19 are constructed in the mud accumulation body 21 from top to bottom on the surface of the pressure retaining wall 17, the first row has 7 grouting holes, the second row has 5 grouting holes, and the third row has 5 grouting holes, the positions of the grouting holes are determined according to the standard that the drilling machine can work, and the distance between the terminal holes 20 of the grouting holes 19 is 2.0 m-2.5 m. The three rows of grouting holes 19 are arranged in a quincunx shape, and the mud accumulation body 21 is reinforced by using double-liquid grouting.

[0062] Step four: curtain grouting

[0063] First, as shown in Figure 1 and Figure 2As shown, two rows of first grouting holes 22 and second grouting holes 23 with a diameter of 50mm are arranged between the primary steel arches within the range of ±50° of the tunnel center line, the row spacing at the opening is 30cm, and the transverse hole spacing between adjacent two holes is 20cm; the included angle between the first grouting hole 22 and the horizontal plane is 65°, the included angle between the second grouting hole 23 and the horizontal plane is 45°, and the reinforcing length of the first grouting hole 22 and the second grouting hole 23 along the tunnel longitudinal direction is not more than 12m. A small conduit with a length of 4m, 4.5m and a diameter of 42mm is respectively placed in the first grouting hole 22 and the second grouting hole 23 to facilitate small conduit grouting, and the grouting pressure is not more than 0.5MPa;

[0064] Then, as shown in Figure 2 , a plurality of curtain grouting holes 24 extending to the mud accumulation body 21 are arranged from the surface of the pressure block 17 to the mud accumulation body 21, the diameter of the curtain grouting hole 24 is 146mm, the opening angle avoids the existing grouting hole 19 as much as possible, and the terminal hole position of the curtain grouting hole 24 penetrates through the mud gushing port 25 to the front of the mud gushing port 25, that is, Figure 2 , the surrounding rock boundary, and the reinforcing length of the curtain grouting hole 24 along the tunnel longitudinal direction is not more than 30m; a geological casing with a length penetrating through the mud accumulation body 21 and a diameter of 127mm is placed in the curtain grouting hole 24 to facilitate curtain grouting, and the grouting method adopts pressure grouting method to carry out grouting, and the maximum grouting pressure is not more than 6MPa.

[0065] Step five: hydrophobic pressure relief hole arrangement

[0066] As shown in Figure 3 , a plurality of hydrophobic pressure relief holes 27 for hydrophobic are arranged on the side wall 26 of the position of the opposite tunnel corresponding to the mud gushing port 25, a plurality of hydrophobic pressure relief holes 27 are arranged in parallel and spaced apart within the range of 4m on both sides with the mud gushing port 25 as the center, the diameter of the hydrophobic pressure relief hole 27 is 127mm, the spacing is 2m, and the terminal hole position extends into the confined water bag 28; a geological casing with a length of 12m and a diameter of 108mm is arranged in each hydrophobic pressure relief hole 27, and a valve is arranged at the end of the geological casing.

[0067] In the process of hydrophobic of the hydrophobic pressure relief hole 27, the amount of silt carried by each hydrophobic pressure relief hole 27 is counted, for the holes with silt carrying amount exceeding 2m 3 / h, the valve of the hole is closed after continuous hydrophobic for more than 10 days, the hydrophobic pressure relief hole 27 farthest from the hole is opened, and the same is true for the other holes; when the silt amount of each hydrophobic pressure relief hole does not exceed 2m 3 / h, but the total silt amount of all holes exceeds 600m 3 , all valves are closed for grouting; after 3 days of grout consolidation, all valves are opened for continuous hydrophobic.

[0068] Step six: curtain grouting and hydrophobic pressure relief are cooperated

[0069] The curtain grouting and the water release pressure are simultaneously carried out. After the grout appears in the water release pressure hole 27, the grouting channel and the water channel are connected, the valve on each water release pressure hole 27 is closed, the water release pressure is stopped, the grouting hole sealing of each water release pressure hole 27 is sequentially carried out, and the water release is permanently stopped. After the curtain grouting is finished, the treatment effect is good after inspection, the arch protection 1, the mud retaining wall 12 and the pressure block 17 are removed, and the tunnel construction is continuously carried out after dredging.

[0070] The above is only the preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can modify or change the above disclosed technical content to equivalent embodiments. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present application without departing from the technical scheme of the present application still belongs to the protection scope of the present application.

Claims

1. A method for treating mudflow in a bidirectional separated tunnel crossing a pressurized water-bearing stratum, characterized in that, Includes the following steps: Step 1: Construction of the arch support A temporary arch (1) is constructed from the end boundary of the silt deposit (21) away from the working face. The arch (1) is attached to the existing lining (2). The arch (1) is provided with several sections, and adjacent arches (1) are connected into a whole by steel bars (9). The first two arches (1) near the tunnel face have several first transverse steel bars (10) set at intervals along the height direction on the inner walls of both sides of each arch (1), and several first vertical steel bars (11) set at intervals along the tunnel width direction on the ground where each arch (1) is located. Step 2: Construction of the mud wall A mud wall (12) with a narrow top and a wide bottom is constructed. The bottom of the mud wall (12) is connected to the first vertical steel bar (11) on the ground, and the side is connected to the first horizontal steel bar (10) on the protective arch (1). A drainage pipe (16) is reserved at the bottom of the mud wall (12). Step 3: Construction of mudflow blocking measures A retaining wall (17) is constructed on the surface of the silt accumulation body (21). One end of the retaining wall (17) is connected to the existing lining (2), and the other end is fixedly connected to the retaining wall (12). Multiple rows of grouting holes (19) are constructed from top to bottom into the silt accumulation body (21) on the surface of the retaining wall (17), and the silt accumulation body (21) is reinforced by grouting. Step 4: Curtain Grouting The first grouting hole (22) and the second grouting hole (23) are made between the initial support steel arch frames within ±50° of the tunnel centerline for small pipe grouting; several curtain grouting holes (24) are made from the surface of the retaining wall (17) to cover the silt accumulation body (21) to the front of the mud inflow port (25) for curtain grouting. Step 5: Construction of hydrophobic pressure relief holes Several drainage and pressure relief holes (27) are made on the sidewall (26) of the opposite tunnel position corresponding to the mud inlet (25). The drainage and pressure relief holes (27) pass through the partition wall between the two tunnels and extend into the pressure water bladder (28) for drainage. Each drainage and pressure relief hole (27) is equipped with a geological casing for hole protection and grouting sealing. A valve is installed at the end of the geological casing. Step Six: Curtain grouting and hydrophobic pressure relief are carried out in tandem. The curtain grouting and the drainage of the drainage and pressure relief holes (27) are carried out simultaneously. When grout appears in the drainage and pressure relief holes (27), the valve is closed to stop the drainage and pressure relief. Grouting is carried out on each drainage and pressure relief hole (27) in sequence to permanently stop the drainage. After the curtain grouting is completed, the arch support (1), mud retaining wall (12) and pressure block (17) are removed. After dredging, the tunnel construction continues.

2. The method for treating mudslides in a bidirectional separated tunnel crossing a pressurized water-bearing stratum according to claim 1, characterized in that, In step one, the arch support (1) is fixedly connected to a pad (4) at the arch foot (3), and the pad (4) is fixedly connected to the tunnel invert arch (7); several arch support (1) are set parallel to each other along the longitudinal direction of the tunnel, with the farthest distance from the tunnel face being 20m.

3. The method for treating mudslides in a bidirectional separated tunnel crossing a pressurized water-bearing stratum according to claim 1, characterized in that, In step three, the specific connection method of the mud wall (12) and the pressure bar (17) is as follows: the mud wall (12) has a platform (13) near the top facing the tunnel face; the mud wall (12) is provided with a second transverse steel bar (14) extending towards the platform (13), and the platform (13) is provided with a second vertical steel bar (15) extending towards the tunnel arch. The second transverse steel bar (14) and the second vertical steel bar (15) are fixedly connected at an intersection; one end of the pressure bar (17) connected to the mud wall (12) is fixedly connected to the platform (13) by the second transverse steel bar (14) and the second vertical steel bar (15).

4. The method for treating mudslides in a bidirectional separated tunnel crossing a pressurized water-bearing stratum according to claim 1, characterized in that, In step four, the angle between the first grouting hole (22) and the horizontal plane is 65°, and the angle between the second grouting hole (23) and the horizontal plane is 45°; the reinforcement length of the first grouting hole (22) and the second grouting hole (23) along the longitudinal direction of the tunnel does not exceed 12m; the grouting pressure of the first grouting hole (22) and the second grouting hole (23) does not exceed 0.5MPa.

5. The method for treating mudslides in a bidirectional separated tunnel crossing a pressurized water-bearing stratum according to claim 1, characterized in that, In step four, the reinforcement length of the curtain grouting hole (24) along the longitudinal direction of the tunnel shall not exceed 30m; the curtain grouting hole (24) shall be grouted by pressure grouting method, and the grouting pressure shall not exceed 6MPa.

6. The method for treating mudslides in a bidirectional separated tunnel crossing a pressurized water-bearing stratum according to claim 1, characterized in that, In step five, several hydrophobic pressure relief holes (27) are set in parallel at intervals within a range extending 4m to both sides of the mud inlet (25) as the center.

7. The method for treating mudslides in a bidirectional separated tunnel crossing a pressurized water-bearing stratum according to claim 1, characterized in that, In step five, during the drainage process of the hydrophobic pressure relief holes (27), the amount of sediment in each hydrophobic pressure relief hole (27) is counted. For holes carrying more than 2m of sediment... 3 / h of the hydrophobic pressure relief hole (27), after continuous hydrophobic drainage for more than 10 days, the valve on the hydrophobic pressure relief hole (27) is closed, and the hydrophobic pressure relief hole (27) farthest from the hydrophobic pressure relief hole (27) is opened; When the amount of sediment in each hydrophobic pressure relief pore (27) does not exceed 2m 3 / h, but the total sediment load of all hydrophobic pressure relief pores (27) exceeds 600m. 3 Afterwards, close all valves to perform grouting; after the grout has solidified for 3 days, open all valves to continue drainage.

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