CN116006244A

CN116006244A - Safety operation isolation protection system for gas tunnel

Info

Publication number: CN116006244A
Application number: CN202211709557.3A
Authority: CN
Inventors: 朱海明; 郑仕跃; 柯善剑; 周靖尧; 彭文彬; 张仁坤
Original assignee: China Construction International Engineering Co ltd; China Overseas Construction Ltd
Current assignee: China Construction International Engineering Co ltd; China Overseas Construction Ltd
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-04-25

Abstract

The invention relates to the technical field of gas tunnel construction, in particular to a gas tunnel safe operation isolation protection system.

Description

Safety operation isolation protection system for gas tunnel

Technical Field

Background

The outburst prevention treatment of the gas tunnel is an important work in the gas tunnel construction process. After the outburst prevention treatment is carried out on the gas tunnel, the gas is ensured not to be outstanding in the construction stage, and the tunnel construction is safely and smoothly completed. When the gas tunnel is subjected to outburst prevention treatment, the gas in the geologic body within a certain range of the outer contour of the gas tunnel is subjected to outburst prevention treatment, and along with the reduction of the gas concentration of a treated area, the gas in an untreated area can leak towards the treated area, and meanwhile, the gas can leak into the gas tunnel through the treated area, so that the use safety performance of the tunnel is affected. Meanwhile, the gas tunnel in operation has potential safety hazard due to leakage and aggregation of gas.

Disclosure of Invention

The invention mainly aims to provide a gas tunnel safe operation isolation protection system, which aims to solve the technical problem that potential safety hazards exist in an operating gas tunnel due to leakage and aggregation of gas in the related technology.

In order to achieve the above object, in a first aspect, the present invention provides a gas tunnel safe operation isolation protection system, where the gas tunnel includes an primary support layer formed in a geological body, the gas tunnel safe operation isolation protection system includes:

a first isolation layer formed within the geologic volume outside of the primary sheath;

the isolation structure is formed on the inner side of the primary support layer, a water and gas discharge space is formed between the isolation structure and the primary support layer, and the isolation structure can isolate gas in the water and gas discharge space; the method comprises the steps of,

the water-gas separation system is arranged in the water-gas discharge space, and can separate liquid and gas which leak out of the water-gas mixture in the geologic body and respectively discharge the liquid and the gas out of the gas tunnel.

Optionally, a second isolation layer is further disposed between the isolation structure and the primary support layer, and the water vapor discharge space is formed between the second isolation layer and the primary support layer.

Optionally, the isolation structure includes:

the secondary lining layer consists of at least two lining rings which are sequentially connected along the excavation direction of the gas tunnel, each lining ring is formed by enclosing at least two lining blocks which are connected end to end along the circumferential direction of the gas tunnel, and construction joints are formed between any two adjacent lining rings and between any two adjacent lining blocks;

the first water stop is arranged in the construction joint; the method comprises the steps of,

the second water stop is arranged corresponding to the construction joint and is clamped between the secondary lining layer and the second isolation layer.

Optionally, the secondary lining layer is made of concrete casting with an air-tight agent added.

Optionally, a foam cushion layer is further arranged between the second isolation layer and the primary support layer, and the foam cushion layer is filled in the water and air discharge space.

Optionally, the water-gas discharging space includes a first space, and a second space and a third space which are respectively communicated with the first space, the first space is arranged corresponding to the arch of the gas tunnel, the second space is arranged corresponding to the arch of the gas tunnel, and the third space is arranged corresponding to the inverted arch of the gas tunnel;

the water-gas separation system comprises:

the gas discharge pipeline is arranged in the second space along the excavation direction of the gas tunnel;

the water discharge pipeline is arranged in the third space along the excavation direction of the gas tunnel; the method comprises the steps of,

the pipeline separating mechanisms are installed in the first space at intervals along the excavation direction of the gas tunnel, the top ends of the pipeline separating mechanisms are communicated with the gas discharge pipeline, and the bottom ends of the pipeline separating mechanisms are communicated with the water discharge pipeline.

Optionally, each of the pipe separation mechanisms includes:

the first pipeline is arranged along the excavation direction of the gas tunnel;

the bottom end of the second pipeline is communicated with the first pipeline, and the top end of the second pipeline is communicated with the gas discharge pipeline;

the top end of the third pipeline is communicated with the first pipeline, the bottom end of the third pipeline is communicated with the water discharge pipeline, the position, away from the first pipeline, of the third pipeline is bent downwards to form a leakage-proof section, and the height of the leakage-proof section is lower than the communication position of the third pipeline and the first pipeline.

Optionally, the leakage-proof section is provided with a conduit, the bottom end of the conduit is communicated with the leakage-proof section, and the top end of the conduit is communicated with the water discharge pipeline.

Optionally, the top of the conduit is not lower than the communication between the third pipeline and the first pipeline.

Optionally, the radial width of the first isolation layer is at least 6m.

According to the technical scheme, the first isolation layer is formed in the geologic body outside the primary support layer, then the isolation structure is formed on the inner side of the primary support layer, the water-gas discharge space is formed between the isolation structure and the first isolation layer, and then the water-gas separation system is installed in the water-gas discharge space.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of an exemplary gas tunnel geological structure of the present invention;

FIG. 2 is a schematic representation of reinforcement of the geological structure illustrated in FIG. 1;

FIG. 3 is a schematic plan view of a reinforced area according to an example of the present invention;

fig. 4 is a schematic structural diagram of an isolation protection system for gas tunnel safety operation according to an example of the invention;

FIG. 5 is a schematic cross-sectional structural view of an exemplary tunnel structure of the present invention;

FIG. 6 is a schematic view of the enlarged structure of the portion E in FIG. 5;

FIG. 7 is a schematic view of the enlarged structure of the portion F in FIG. 5;

FIG. 8 is a schematic diagram of an exemplary water-gas separation system of the present invention;

fig. 9 is a schematic structural view of an isolation structure according to an example of the present invention.

10	Geologic body	332	Second water stop
				100	Primary support layer	333	Foam cushion layer
200	A first isolation layer	410	Gas discharge pipeline
				300	Isolation structure	420	Water discharge pipeline
400	Water-gas separation system	430	Separation pipeline system
				20	Water and air discharge space	431	First pipeline
500	A second isolation layer	432	Second pipeline
				330	Secondary lining layer	433	Third pipeline
331	First water stop	434	Catheter tube
				A	Area to be formed	B	With reinforced areas

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present invention are merely used to explain the relative positional relationship, movement, etc. between the mechanisms in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is correspondingly changed.

In the present invention, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" as it appears throughout includes three parallel schemes, for example "A and/or B", including the A scheme, or the B scheme, or the scheme where A and B are satisfied simultaneously. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present invention.

The inventive concept of the present invention is further elucidated below in connection with some embodiments.

The invention provides a gas tunnel safe operation isolation protection system.

As shown in fig. 1 to 6, an embodiment of the gas tunnel security operation isolation protection system of the present invention is presented.

In this embodiment, referring to fig. 1, the gas tunnel safety operation isolation protection system includes an primary support layer 100 formed in a geological body 10, and the gas tunnel safety operation isolation protection system includes:

a first isolation layer 200, the first isolation layer 200 being formed in the geological body 10 outside the primary support 100;

the isolation structure 300, the isolation structure 300 is formed on the inner side of the primary support layer 100, a water and gas discharge space 20 is formed between the isolation structure 300 and the primary support layer 100, and the isolation structure 300 can isolate gas in the water and gas discharge space 20; the method comprises the steps of,

the water-gas separation system 400 is installed in the water-gas discharge space 20, and the water-gas separation system 400 can separate the liquid and the gas in the water-gas mixture leaked from the geologic body 10 and discharge the liquid and the gas out of the gas tunnel respectively.

In specific implementation, firstly, a geologic body 10 with a minimum clear distance of 6m from the profile surface of a gas tunnel is taken as a region to be reinforced of the first isolation layer 200, then, a region with the minimum clear distance of 10m from the coal seam and after the region passes through the minimum clear distance of 10m from the coal seam along the excavation direction is taken as a region to be reinforced, then, curtain grouting is carried out on the face with the minimum clear distance of 10 from the coal seam on the region to be formed and the region to be reinforced at the same time, so that the region to be formed and the region to be reinforced jointly form a reinforcing body, then, excavation construction is carried out on the face after curtain grouting is completed until the face passes through the minimum clear distance of 10m from the coal seam, a current tunnel section is formed, and radial grouting is carried out on the profile surface of the current tunnel section on the region to be formed, so that the region to be formed is converted into the first isolation layer 200.

It should be noted specifically and explicitly that in this embodiment, the cement slurry is preferably used for curtain grouting, and the cement is preferably used for radial grouting: the water is 1:1 cement single slurry.

According to the technical scheme, the first isolation layer 200 is formed in the geologic body 10 outside the primary support layer 100, then the isolation structure 300 is formed on the inner side of the primary support layer 100, the water-gas discharge space 20 is formed between the isolation structure 300 and the first isolation layer 200, and then the water-gas separation system 400 is installed in the water-gas discharge space 20, the first isolation layer 200 is used for isolating surplus gas in the geologic body 10, and meanwhile the isolation structure 300 is used for isolating gas leaking into the water-gas discharge space 20 in the area beyond the water-gas discharge space 20, so that the gas can be prevented from leaking into a tunnel to influence the safe operation of the tunnel in the specific implementation, the problem that the safety hidden danger exists in the gas tunnel in the operation due to the leakage and aggregation of the gas in the related technology is solved, and meanwhile, the defect that the normal operation of the gas tunnel is influenced due to the leakage and aggregation of the gas caused by the existence of cracks or holes in the geologic body and lining structure of the area where the gas tunnel is located is also solved by arranging the isolation structure.

In some embodiments, a second isolation layer 310 is further disposed between the isolation structure 300 and the primary support layer 100, and the moisture discharge space 20 is formed between the second isolation layer 310 and the primary support layer 100.

In this embodiment, by disposing the second isolation layer 310 between the isolation structure 300 and the primary support layer 100, and forming the water-gas discharge space 20 between the second isolation layer 310 and the primary support layer 100, the present invention can utilize the disposed second isolation layer 310 to secondarily isolate the gas discharged into the water-gas discharge space 20 during implementation, and improve the isolation effect of the isolation system of the present invention, and meanwhile, by disposing the second isolation structure 300, the protection system of the present invention is also applied to the environment where the aldehyde substance is formed after the gas containing the acid gas or a part of the gas in the gas is dissolved in water, so that the corrosion caused by the isolation structure 300 of the substance can be slowed down, and the service life of the protection system of the present invention is improved. And through the second isolation layer 310, the invention can prevent the corrosion of water to the isolation structure 300 in the specific implementation, and ensure the isolation performance of the isolation structure 300.

It should be specifically and explicitly noted that the second insulation layer 310 may be, but not limited to, a gas insulation board, where the gas insulation board is made of a material such as glass fiber cloth, and the invention is only applied, and not related to improvement or design of the structure of the gas insulation board itself, which is not described herein.

In some embodiments, isolation structure 300 includes:

the secondary lining layer 330, the secondary lining layer 330 is composed of at least two lining rings which are sequentially connected along the excavation direction of the gas tunnel, each lining ring is formed by enclosing at least two lining blocks which are connected end to end along the circumferential direction of the gas tunnel, and construction joints are formed between any two adjacent lining rings and between any two adjacent lining blocks;

the first water stop 331, the first water stop 331 is set up in the construction joint; the method comprises the steps of,

the second water stop 332, the second water stop 332 is disposed corresponding to the construction joint and is clamped between the secondary lining layer 330 and the second isolation layer 310.

In this embodiment, by arranging the secondary lining layer 330 and arranging the first water stop 331 in each construction joint of the secondary lining layer 330 and simultaneously sandwiching the second water stop 332 between the secondary lining layer 330 and the second isolation layer 310, the sealing effect of the construction joint can be improved by the two layers of water stops, so that the gas can be completely isolated at one side of the secondary lining layer 330 close to the second isolation layer 310.

It is specifically and explicitly noted that in the present embodiment, the first water stop 331 and the second water stop 332 may be exemplified as water-swellable water stops. The exemplary secondary backing layer 330 is made using concrete casting with the addition of an air-tight agent.

In some embodiments, the secondary backing layer 330 is made of concrete casting with the addition of an air-tight agent.

In this embodiment, the secondary lining layer 330 is made by casting concrete with an airtight agent, so that the sealing performance of the whole secondary lining layer 330 can be improved during specific implementation, and gas can be effectively prevented from leaking into the tunnel from the secondary lining layer 330.

It should be noted in particular and explicitly that in the present embodiment, the concrete and the amount of the air-tight agent added in the concrete exemplified at least satisfy the following components: the amount of air-tight agent added per cubic concrete was 2% of the amount of cement per cubic concrete.

In some embodiments, a foam cushion 333 is further disposed between the second insulating layer 310 and the primary support layer 100, and the foam cushion 333 fills the moisture discharge space 20.

In this embodiment, by disposing the foam pad 333 between the second isolation layer 310 and the primary support layer 100, the present invention can prevent a sharp object from invading into the second isolation layer 310 to damage the second isolation layer 310 during implementation, thereby improving the protection performance of the protection system of the present invention.

It should be specifically and explicitly noted that, in this embodiment, the installation sequence of the foam cushion layer is that, after the primary support layer 100 is completed, the water-gas separation system is installed on the inner side of the primary support layer, after the installation of the water-gas separation system is completed, the foam cushion layer 333 is installed on the inner side of the water-gas separation system, and after the installation of the foam cushion layer 333 is completed, the second isolation plate is installed on the inner side of the foam cushion layer 333 until the entire protection system is constructed.

In some embodiments, the water-gas discharge space 20 includes a first space and a second space and a third space respectively communicated with the first space, the first space is disposed corresponding to a waisted portion of the gas tunnel, the second space is disposed corresponding to a dome of the gas tunnel, and the third space is disposed corresponding to an inverted arch of the gas tunnel;

the water-gas separation system 400 includes:

a gas discharge pipe 410 installed in the second space along the excavation direction of the gas tunnel;

a water discharge pipe 420, the water discharge pipe 420 being installed in the third space along an excavation direction of the gas tunnel; the method comprises the steps of,

the at least two pipeline separating mechanisms are installed in the first space at intervals along the excavation direction of the gas tunnel, the top end of each pipeline separating mechanism is communicated with the gas discharge pipeline 410, and the bottom end of each pipeline separating mechanism is communicated with the water discharge pipeline 420.

In this embodiment, the gas discharge pipeline 410 is disposed in the second space, the water discharge pipeline 420 is disposed in the third space, and the pipeline separation mechanism is disposed in the first space, so that when the invention is implemented, water and gas in the water-gas mixture extending into the first space can be separated by inherent properties, and a power mechanism is not required to be separately disposed, thereby improving the convenience of the gas isolation protection system of the invention.

In some embodiments, each of the line separation mechanisms includes:

the first pipeline 431, the first pipeline 431 is arranged along the excavation direction of the gas tunnel;

a second pipeline 432, wherein the bottom end of the second pipeline 432 is communicated with the first pipeline 431, and the top end of the second pipeline 432 is communicated with the gas discharge pipeline 410;

the top end of the third pipeline 433 is communicated with the first pipeline 431, the bottom end of the third pipeline 433 is communicated with the water discharge pipeline 420, and the position, away from the first pipeline 431, of the third pipeline 433 is bent downwards to form a leakage-proof section, and the height of the leakage-proof section is lower than the communication position of the third pipeline 433 and the first pipeline 431.

In this embodiment, the first pipe 431 is used for passing the water vapor mixture oozed out of the geological body 10, so that the gas in the water vapor mixture is discharged into the gas discharge pipe 410 through the second pipe 432, and the liquid in the water vapor mixture is discharged into the water discharge pipe 420 through the third pipe 433. So that the water and the gas can be discharged respectively. Meanwhile, the position of the third pipeline 433 far away from the first pipeline 431 is downwards bent to form a leakage-proof section, and the height of the leakage-proof section is lower than the communication position of the third pipeline 433 and the first pipeline 431, so that gas can be prevented from flowing into a tunnel from the third pipeline 433 during specific implementation, pollution to the tunnel is caused, and the safety performance of the tunnel during use is improved.

In some embodiments, the leak-proof section is provided with a conduit 434, the bottom end of the conduit 434 is in communication with the leak-proof section and the top end is in communication with the water discharge conduit.

In this embodiment, by arranging the conduit 434, the leakage preventing section is communicated with the water discharge pipeline by using the conduit 434, so that the hidden trouble of gas leakage into the tunnel caused by lack of water in the leakage preventing section can be avoided in implementation of the invention.

In some embodiments, the top of conduit 434 is not lower than where third conduit 433 communicates with first conduit 431.

In this embodiment, the top of the conduit 434 is not lower than the communication position between the third pipeline 433 and the first pipeline 431, so that the leak-proof section and the bending section can always store water during implementation of the present invention, and the sealing performance of the third pipeline 433 is improved.

In some embodiments, the radial width of the first separator layer 200 is at least 6m.

In some embodiments, a plurality of fissures also exist within the tunnel surrounding rock; the gas outburst prevention treatment is applied to measures such as pumping drilling, hydraulic slotting or hydraulic fracturing, and holes or cracks are formed in the coal seam; holes are formed in surrounding rock by measures such as anchor rods, foot locking anchor rods or advanced support of a tunnel primary support construction system; a gap formed by incompletely attaching the sprayed soil and the surrounding rock; and under the influence of surrounding rock convergence deformation and settlement, cracks can be formed in the rock mass. These are channels where gas overflows into the tunnel at the crevices or gaps. The gas outburst control mainly ensures that the gas is not outburst in the tunnel construction stage, but in the tunnel traffic operation stage, under the action of gas pressure and concentration gradient difference, the gas moves into the tunnel along cracks or holes, and possibly permeates into the traffic tunnel, so that a large potential safety hazard exists.

The invention aims to prevent gas from penetrating into the back of the lining through surrounding rock column writing and channels by grouting and solidifying surrounding rock and a coal seam; the gas which is slightly permeated into the tunnel is blocked behind the secondary lining through the partition and the discharge system arranged in the tunnel supporting and lining system, and is drained to the hole through draining the pipeline behind the lining, so that the gas is not permeated into the tunnel, and the safe operation in the gas tunnel is ensured.

Grouting surrounding rock and coal bed curtains in the range of 5-6m along the tunnel length, which are close to the coal bed group 10m and far from the coal bed group 10m, along the tunnel excavation contour line, and filling surrounding rock cracks, gaps and holes formed by gas control with cement slurry, and solidifying the surrounding rock cracks, the gaps and the holes into a whole to form a barrier, so that the gas is isolated outside the ring; after the tunnel is completed and the shotcrete construction is performed, radial small guide pipes 434 are used for grouting, so that cracks or holes formed in the rock mass are closed. Through two-wheel grouting, a circle of integral surrounding rock body is formed within the range of 6m behind the tunnel lining of the tunnel, and gas at the isolated section permeates into the lining clearance.

The primary support is provided with a water-gas separation device, a gas discharge pipeline, an antistatic polyethylene closed-pore foam plate, an outer isolation plate, a secondary lining concrete structure of an air-entraining sealant, a buried water stop belt and a back-attached water stop belt which are added in a secondary lining construction joint, the water exuding outside the tunnel is isolated between the treatment support and the gas isolation plate, and the gas is collected and guided to the gas discharge pipeline arranged on the vault of the tunnel through the gas-water separation device to be discharged to a tunnel portal, so that the safe operation of the gas tunnel is ensured.

Meanwhile, the invention also provides a construction method of the protection system, which comprises the following steps:

and S201, after the gas in a certain tunnel is treated in a protruding way, at the moment, the tunnel face is 10m away from the normal line of the coal seam, and C25 injection concrete with the thickness of 20cm is adopted to seal the tunnel face completely.

S202, after sealing is completed, arranging annular grouting holes on the tunnel face, wherein the grouting holes are distributed in an umbrella shape from the tunnel center line, the annular spacing of the grouting hole openings is 50cm, the spacing of each annular is about 2m, and the hole bottom spacing is not more than 3m; and 3 rings of grouting pipe holes are longitudinally formed, the grouting section is 30m long, 3 rings are divided, the first ring is 12m long, the second ring is 20m long, the third ring is 30m long, and a grouting rock stopping disc serving as a lower section is not excavated after grouting in the first section is completed.

S203, burying a seamless steel pipe with the diameter of 108mm in the drill hole as an orifice pipe, wherein the length of the orifice pipe is 3m, and exposing 20-30cm outside the face.

S204, after the orifice pipe is buried, an anchoring agent is adopted to block the air between the orifice pipe and the sprayed concrete into a labyrinth chamber, a gap of about 1cm is reserved, cotton yarn, cement mortar or AB glue are adopted and used for blocking the orifice, after the orifice is partially solidified, a 6m steel plate is adopted for welding the exposed 108 orifice pipe, and a grouting tap with the diameter of 4cm is adopted for welding on the steel plate to serve as a grouting port.

S205, grouting, namely grouting from inside to outside according to construction, sequentially grouting from the two sides of the tunnel to the vault from the bottom of the inverted arch by each ring, wherein 1:1 cement single-liquid slurry is adopted for grouting, initial grouting pressure is 0.5-1.0MPa, and final grouting pressure is 2.0MPa; the slurry diffusion radius was 2m. The second ring, then the third ring and the fourth ring are applied after the grouting is completed on the first ring,

s206, reinforcing the coal bed, and uncovering the coal bed by adopting a progressive uncovering mode after construction and solidification are completed. And (5) carrying out a second round of curtain grouting after the construction of the coal seam is uncovered for 26m, and not carrying out curtain grouting after the curtain grouting is carried out until the distance from the normal line of the coal seam is 10 m.

S207, when the inverted arch completes the primary support, after the surrounding rock horizontally converges and the vault subsides stably, grouting is started after the primary support is carried out, and a length section of grouting behind the primary support is defined as a length range which is close to the normal line 10m of the coal bed and is far from the normal line 10m after coal uncovering is completed.

And S208, grouting behind the primary support, wherein the grouting sequence sequentially extends from the bottom of the inverted arch part to the side wall and the vault sequentially until the end far from the normal line of the coal bed is finished.

The gas isolation system, which is composed of curtain grouting and small conduit 434 system grouting, blocks gas outside the excavation contour line, and prevents gas from penetrating into the excavation contour line as much as possible.

S209, after the primary support is completed, installing a water-steam separation device, wherein water-steam mixed gas enters through a tee joint, and is discharged to a tunnel portal through a circumferential soft permeable pipe; the water enters into the end head and is discharged into the central drainage ditch of the tunnel to be beaten out of the hole.

The annular soft permeable pipe is fixedly arranged along the surface of the sprayed concrete, a channel is formed between the primary support and the gas isolation plate, surface water seepage can be collected, and the water flows downwards along the hose into the longitudinal drain pipe at the side wall; the annular soft permeable pipe can collect gas, and the gas can enter an exhaust pipe arranged on a vault upwards, the exhaust pipe is arranged along the whole length of a tunnel, the coal-based stratum section is an HDPE DN/ID100 double-wall corrugated pipe, and a 100PVC pipe is adopted in a non-gas section.

S209, after the water-steam separation device and the water drainage and exhaust pipeline, fixing an antistatic polyethylene closed-pore foam board on the surface of the sprayed concrete, and completely covering the surface of the sprayed concrete and the pipeline to prevent sharp objects from penetrating through the gas isolation board; and installing a gas isolation plate, paving the gas isolation plate along the whole width of the tunnel, wherein the width of the gas isolation plate is 2-2.5m, the gas isolation plate is connected with each other by adopting a seam welder in a hot melting way, the connection width is not less than 15cm, and the gas isolation plate can be continuously paved after an inflation test detects no gas leakage.

210. The secondary lining concrete can be constructed only after the installation of the gas isolation plate and the detection is qualified, the airtight agent is added into the concrete according to the design requirement, the compactness of the concrete is improved, the waterproof capability is improved, a back-attached water stop with the width of 30cm is installed at the back of the secondary lining concrete at a concrete construction joint, and a buried water stop is installed at the middle position of the thickness of the concrete.

S211, curtain grouting and radial grouting reinforcement can be carried out on the periphery of the tunnel contour line, so that a first gas isolation layer is formed, cracks and holes in the coal bed and surrounding rock are closed, a gas overflow channel is blocked, the effect of isolating external gas is achieved, the gas is isolated from the tunnel excavation contour line by 6m, and the stability coefficient of the coal bed can be improved; the second gas partition system is composed of an antistatic polyethylene closed-cell foam board, a gas isolation board, secondary lining concrete of an air-entraining sealant, a back-attached water stop belt and a buried water stop belt structure: and sealing the gas escaping through the gas partition system, and discharging the gas out of the hole by utilizing a water-gas separation device, a water-gas drainage and exhaust system consisting of a circumferential soft water-permeable pipe and a vault longitudinal exhaust pipe, so that the gas is prevented from penetrating into the tunnel as much as possible, and the operation safety of the gas tunnel engineering is improved.

In this embodiment, the technical solution of the present invention is to form the first isolation layer 200 in the geologic body 10 outside the primary support layer 100, then form the isolation structure 300 inside the primary support layer 100, form the water-gas discharge space 20 between the isolation structure 300 and the first isolation layer 200, and install the water-gas separation system 400 in the water-gas discharge space 20, isolate the surplus gas in the geologic body 10 by using the first isolation layer 200, and isolate the gas leaking into the water-gas discharge space 20 in the region beyond the water-gas discharge space 20 by using the isolation structure 300, so that the gas leakage into the tunnel can be avoided during specific implementation to affect the safe operation of the tunnel, and the problem that the gas tunnel in operation is safe due to the leakage and aggregation of the gas in the related art is solved.

The foregoing description is only of the optional embodiments of the present invention, and is not intended to limit the scope of the invention, and all the equivalent structural changes made by the description of the present invention and the accompanying drawings or the direct/indirect application in other related technical fields are included in the scope of the invention.

Claims

1. A gas tunnel safe operation isolation protection system, the gas tunnel including an primary support layer formed within a geologic body, the gas tunnel safe operation isolation protection system comprising:

2. The gas tunnel safe operation isolation protection system of claim 1, wherein a second isolation layer is further provided between the isolation structure and the primary support layer, and the water vapor discharge space is formed between the second isolation layer and the primary support layer.

3. The gas tunnel safe operation isolation protection system of claim 2, wherein the isolation structure comprises:

4. The gas tunnel safety operation isolation protection system of claim 3, wherein the secondary lining layer is made of concrete casting added with an air-tight agent.

5. The gas tunnel safety operation isolation protection system according to claim 3, wherein a foam cushion layer is further arranged between the second isolation layer and the primary support layer, and the foam cushion layer is filled in the water-gas discharge space.

6. The gas tunnel safe operation isolation protection system according to any one of claims 1 to 5, wherein the water-gas discharge space includes a first space, which is provided corresponding to a waisted of the gas tunnel, and a second space and a third space, which are respectively communicated with the first space, which is provided corresponding to a vault of the gas tunnel, and which is provided corresponding to an inverted arch of the gas tunnel;

the water-gas separation system comprises:

7. The gas tunnel safe-operation isolation protection system of claim 6, wherein each of said pipe separation mechanisms comprises:

8. The gas tunnel safe operation isolation protection system of claim 7, wherein the leak-proof section is provided with a conduit, a bottom end of the conduit is in communication with the leak-proof section, and a top end is in communication with the water discharge conduit.

9. The gas tunnel safe operation isolation protection system of claim 8, wherein a top of the conduit is not lower than a communication of the third conduit with the first conduit.

10. The gas tunnel safe-operation insulation protection system of any one of claims 1-5, wherein a radial width of the first insulation layer is at least 6m.