Manhole overhaul channel structure of compressed air energy storage artificial chamber gas storage and construction method of manhole overhaul channel structure

Abstract

According to the compressed air energy storage artificial chamber gas storage manhole overhaul channel structure and the construction method thereof, the manhole overhaul channel is poured in the gas storage plugging structure concrete, and the two ends of the manhole overhaul channel communicate with the artificial chamber gas storage and the traffic tunnel correspondingly, so that entering and exiting of personnel during gas storage overhaul are achieved; maintenance materials and maintenance equipment are convenient to transport. The flange of the manhole overhaul channel is arranged on the side close to the traffic tunnel, the sealing performance of the manhole overhaul channel can be guaranteed, gas leakage of the gas storage can be prevented, large machines can be conveniently used when a flange cover is disassembled during overhaul of the gas storage, and the overhaul construction efficiency is improved. The manhole overhaul channel extends out of the plugging body structure for a certain length, so that the gas storage gas charging and discharging port and the reserved wire inserting port are formed in the side edge of the manhole overhaul channel instead of being formed in a flange cover traditionally, the work of disassembling and assembling a gas charging and discharging pipeline and a monitoring cable when a flange is disassembled is omitted, and the working efficiency is improved. The influence of gas storage overhaul construction on the inflation and deflation pipeline and the monitoring cable is reduced, and the overhaul construction efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of compressed air energy storage, and in particular to a manhole inspection channel structure of an artificial chamber gas storage reservoir for compressed air energy storage and a construction method thereof. Background Art

[0002] When a large diameter circular cross-section chamber is excavated in a hard rock formation as a high-pressure gas storage, the entry and exit of personnel during the maintenance of the gas storage is inconvenient, and the transportation of maintenance materials and maintenance equipment is inconvenient. The sealing performance of the manhole maintenance channel and the performance of preventing gas leakage in the gas storage cannot be guaranteed, which is inconvenient for the use of large machinery when removing the flange cover during the maintenance of the gas storage, reducing the efficiency of maintenance construction. Traditionally, it is set on the flange cover. When the flange is disassembled, the disassembly and installation of the gas filling and discharging pipelines and monitoring cables will affect the gas storage maintenance construction on the gas filling and discharging pipelines and monitoring cables, reducing the efficiency of maintenance construction. Summary of the invention

[0003] In order to solve the above technical problems, one of the technical solutions adopted by the present invention is: a manhole inspection channel structure of a compressed air energy storage artificial chamber gas storage reservoir, the structure comprising:

[0004] Gas storage 1;

[0005] A traffic tunnel 3, wherein the traffic tunnel 3 and the gas storage reservoir 1 are arranged perpendicular to each other;

[0006] The blocking structure 2 is located at the junction of the gas storage reservoir 1 and the traffic tunnel 3;

[0007] The ordinary straight pipe section 4, the curved pipe section 6, and the straight pipe section with flange 7 are connected in sequence;

[0008] Among them, the ordinary straight pipe section 4 is close to the gas storage reservoir 1, and the straight pipe section with flange 7 is close to the traffic tunnel 3;

[0009] The joints of the ordinary straight pipe section 4, the curved pipe section 6, and the straight pipe section with flange 7 are provided with double-sided beveled welding connection ends 5;

[0010] The straight pipe section 6 with flange extends to the side of the traffic tunnel 3, and a gas storage filling and discharging port 8 and a reserved plug-in port 9 are set. The gas storage filling and discharging port 8 is arranged on the opposite side, and the reserved plug-in port 9 is set at the bottom of the maintenance channel to facilitate the subsequent steel plate protection at the bottom of the maintenance channel;

[0011] A flange cover 10 is provided at the port of the traffic tunnel 3 and is installed by a bolt and nut assembly 11 .

[0012] Furthermore, the ordinary straight pipe section 4 is a circular steel pipe with an outer diameter of 1.0 to 1.8 mm and a wall thickness of 50 to 150 mm. One end of the ordinary straight pipe section 4 is flush with the blocking structure, and the other end is connected to the curved pipe section 6 .

[0013] Furthermore, the curved pipe section 6 is formed by bending the ordinary straight pipe section 4 through a specific large-scale mechanical pressing, and the inner and outer diameters of the curved pipe section 6 are consistent with those of the ordinary straight pipe section 4. The curved pipe section 6 is respectively connected to the ordinary straight pipe section 4 and the straight pipe section 7 with flange.

[0014] Furthermore, the flange cover 10 is a concave steel plate structure with the notch facing outward, so that the force on the flange cover 10 is uniform; the center thickness of the flange cover 10 is 15 to 20 cm, and the edge thickness is 30 to 40 cm. The structure with thick edges and thin centers can effectively reduce the weight of the flange cover 10 and reduce the difficulty of disassembly and installation of the flange cover 10 during maintenance.

[0015] Furthermore, before welding the double-sided grooved welding connection 5, a double-sided groove is first cut on the end of the steel pipe to increase the surface area of ​​the welding connection and improve the welding connection performance.

[0016] Furthermore, the manhole inspection channel is cast inside the blocking structure 2, the centerline of the manhole inspection channel coincides with the centerline of the blocking structure 2, the distance from the bottom plate of the manhole inspection channel to the bottom plate of the gas storage reservoir 1 is 0.5m, and the two ends of the manhole inspection channel are respectively connected to the artificial chamber gas storage reservoir 1 and the traffic tunnel 3, so as to realize the entry and exit of personnel and the transportation of maintenance materials and maintenance equipment during the maintenance of the gas storage reservoir 1.

[0017] Another technical solution adopted by the present invention is: a construction method for the manhole inspection channel structure of the above-mentioned compressed air energy storage artificial chamber gas storage reservoir, the method comprising:

[0018] S1. Chamber excavation and support:

[0019] The longitudinal traffic tunnel 3, the blocking structure 2 and the gas storage reservoir 1 are excavated and supported in sequence. The traffic tunnel 3 and the blocking structure are only supported in the initial stage, and the gas storage reservoir 1 needs to be poured with secondary lining after the initial support is completed;

[0020] S2. Manhole inspection channel production and processing:

[0021] Through a specific large-scale machine, the steel plate is curled and welded to form two sections of ordinary straight pipe sections 4 and one section of straight pipe section with flange 7, and the ordinary straight pipe section is bent to form a curved pipe section 7. Bolt holes are drilled at the corresponding positions of the flange, and holes are drilled for reserved gas filling and discharge ports 8 and reserved wire insertion ports 9;

[0022] Among them, the steel pipe formed by S201 and curled steel plate has only one welding seam, and submerged arc automatic welding equipment is used to ensure the quality of the weld;

[0023] S3. Concrete pouring of the first layer of the blocking structure:

[0024] Pour the first layer of concrete for the plugging structure 2. The concrete is C30 micro-expansive concrete with a pouring thickness of 0.5m;

[0025] S4. Installation of operation and maintenance channel:

[0026] The connecting ends of the ordinary straight pipe section 4, the curved pipe section 6 and the straight pipe section with flange 7 are grooved. After the first layer of concrete reaches sufficient structural strength, the ordinary straight pipe section 4 and the curved pipe section 6 are hoisted, and welding construction is started after docking and positioning. Then the straight pipe section with flange 7 is hoisted, and welding construction of the curved pipe section 6 and the straight pipe section with flange 7 is carried out after docking and positioning;

[0027] Among them, when the S401 steel pipe end is grooved, a combination of U-shaped groove and V-shaped groove is adopted. In order to ensure the welding quality, the groove is made by mechanical processing and the groove surface is guaranteed to have a certain roughness;

[0028] S5. Layered pouring of blocking structure:

[0029] C30 micro-expansive concrete is used to cast the plugging structure in layers. The concrete vibration strength is strengthened at the interface between the plugging body and the initial support to reduce the casting pores. At the same time, the backfill grouting pipe is reserved and installed at the interface between the plugging structure and the initial support, especially at the top of the chamber, to facilitate subsequent backfill grouting.

[0030] S6. Concrete maintenance of plugging structure:

[0031] Regularly maintain the cast plugging structure 2 to avoid concrete cracking due to inadequate maintenance and ensure that the concrete reaches the expected strength;

[0032] S7, backfill grouting of plugging structure:

[0033] After the plugging structure 2 is poured, there may still be gaps at the junction of the plugging structure and the surrounding rock, especially at the top of the plugging structure and other locations where concrete pouring is inconvenient. These locations are backfilled and grouted through the backfill grouting pipe to form a backfill grouting body to fill the pores;

[0034] Among them, S701, the slurry for backfill grouting adopts micro-expansive cement slurry, the grouting pressure is 0.2~0.5MPa, the grouting pipe is mainly arranged on the top of the plugging structure, the annular and longitudinal spacing is 1m×1m, and the grouting construction is carried out after the concrete of the sealing structure reaches sufficient strength;

[0035] S8, flange cover installation, construction and commissioning:

[0036] Use a clean rag to thoroughly clean the mounting surfaces of the flange and flange cover, hoist the flange cover 10, and dock and position it with the flange, and use the bolt and nut assembly 11 to connect and fix the flange and flange cover;

[0037] Among them, S801, when installing the bolts, tighten the bolts step by step in a diagonal order, and use a torque wrench to tighten them according to the specified torque value to ensure that the tightening force of each bolt is uniform.

[0038] The advantages and positive effects of the present invention are as follows: the manhole inspection channel is cast inside the concrete of the gas storage plugging structure, and the two ends are connected to the artificial chamber gas storage and the traffic tunnel respectively, so as to realize the entry and exit of personnel during the maintenance of the gas storage, and facilitate the transportation of maintenance materials and maintenance equipment. The flange of the manhole inspection channel is arranged on the side close to the traffic tunnel, which can not only ensure the sealing of the manhole inspection channel and prevent gas leakage of the gas storage, but also facilitate the use of large machinery when the flange cover is disassembled during the maintenance of the gas storage, thereby improving the maintenance construction efficiency. The manhole inspection channel extends a certain length from the plugging body structure, so that the gas storage gas charging and discharging port and the reserved plug-in port can be arranged on the side of the manhole inspection channel, instead of being traditionally arranged on the flange cover, thereby eliminating the need for disassembly and installation of the gas charging and discharging pipeline and the monitoring cable when the flange is disassembled, reducing the impact of the gas storage maintenance construction on the gas charging and discharging pipeline and the monitoring cable, and greatly improving the maintenance construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the gas storage reservoir, plugging body, manhole inspection passage and traffic tunnel;

[0040] Figure 2 for Figure 1 AA section view;

[0041] Figure 3 for Figure 1 BB cross-section diagram;

[0042] Figure 4 A schematic diagram of the manhole inspection channel;

[0043] Figure 5 for Figure 4 CC profile of ;

[0044] Figure 6 for Figure 4 DD profile diagram;

[0045] Figure 7 for Figure 4 EE profile of

[0046] Figure 8 It is a schematic diagram of double-sided groove welding connection at the end of the steel pipe;

[0047] Fig. 9 It is a schematic diagram of a bolt and nut assembly;

[0048] In the figure: 1. Gas storage; 2. Sealing structure; 3. Traffic tunnel; 4. Ordinary straight pipe section; 5. Double-sided beveled welding connection end; 6. Bend pipe section; 7. Straight pipe section with flange; 8. Reserved filling and discharging port; 9. Reserved wiring port; 10. Flange cover; 11. Bolt and nut assembly. DETAILED DESCRIPTION

[0049] In order to better understand the present invention, the present invention is further described below in conjunction with specific embodiments and drawings.

[0050] Example 1

[0051] like Figure 1-Figure 9 As shown, the structure of the manhole inspection channel of the compressed air energy storage artificial chamber gas storage reservoir includes:

[0052] Gas storage 1;

[0053] A traffic tunnel 3, wherein the traffic tunnel 3 and the gas storage reservoir 1 are arranged perpendicular to each other;

[0054] The blocking structure 2 is located at the junction of the gas storage reservoir 1 and the traffic tunnel 3;

[0055] The ordinary straight pipe section 4, the curved pipe section 6, and the straight pipe section with flange 7 are connected in sequence;

[0056] Among them, the ordinary straight pipe section 4 is close to the gas storage reservoir 1, and the straight pipe section with flange 7 is close to the traffic tunnel 3;

[0057] The joints of the ordinary straight pipe section 4, the curved pipe section 6, and the straight pipe section with flange 7 are provided with double-sided beveled welding connection ends 5;

[0058] The straight pipe section 6 with flange extends to the side of the traffic tunnel 3, and a gas storage filling and discharging port 8 and a reserved plug-in port 9 are set. The gas storage filling and discharging port 8 is arranged on the opposite side, and the reserved plug-in port 9 is set at the bottom of the maintenance channel to facilitate the subsequent steel plate protection at the bottom of the maintenance channel;

[0059] A flange cover 10 is provided at the port of the traffic tunnel 3 and is installed by a bolt and nut assembly 11 .

[0060] Furthermore, the ordinary straight pipe section 4 is a circular steel pipe with an outer diameter of 1.0 to 1.8 mm and a wall thickness of 50 to 150 mm. One end of the ordinary straight pipe section 4 is flush with the blocking structure, and the other end is connected to the curved pipe section 6 .

[0061] Furthermore, the curved pipe section 6 is formed by bending the ordinary straight pipe section 4 through a specific large-scale mechanical pressing, and the inner and outer diameters of the curved pipe section 6 are consistent with those of the ordinary straight pipe section 4. The curved pipe section 6 is respectively connected to the ordinary straight pipe section 4 and the straight pipe section 7 with flange.

[0062] Furthermore, the flange cover 10 is a concave steel plate structure with the notch facing outward, so that the force on the flange cover 10 is uniform; the center thickness of the flange cover 10 is 15 to 20 cm, and the edge thickness is 30 to 40 cm. The structure with thick edges and thin centers can effectively reduce the weight of the flange cover 10 and reduce the difficulty of disassembly and installation of the flange cover 10 during maintenance.

[0063] Furthermore, before welding the double-sided grooved welding connection 5, a double-sided groove is first cut on the end of the steel pipe to increase the surface area of ​​the welding connection and improve the welding connection performance.

[0064] Furthermore, the manhole inspection channel is cast inside the blocking structure 2, the centerline of the manhole inspection channel coincides with the centerline of the blocking structure 2, the distance from the bottom plate of the manhole inspection channel to the bottom plate of the gas storage reservoir 1 is 0.5m, and the two ends of the manhole inspection channel are respectively connected to the artificial chamber gas storage reservoir 1 and the traffic tunnel 3, so as to realize the entry and exit of personnel and the transportation of maintenance materials and maintenance equipment during the maintenance of the gas storage reservoir 1.

[0065] The manhole inspection channel is cast inside the concrete of the gas storage plugging structure, and the two ends are connected to the artificial chamber gas storage and the traffic tunnel respectively, so as to realize the entry and exit of personnel during the maintenance of the gas storage and facilitate the transportation of maintenance materials and equipment. The flange of the manhole inspection channel is set on the side close to the traffic tunnel, which can not only ensure the sealing of the manhole inspection channel and prevent gas leakage in the gas storage, but also facilitate the use of large machinery when the flange cover is removed during the maintenance of the gas storage, thereby improving the efficiency of maintenance construction. The manhole inspection channel extends a certain length from the plugging body structure, so that the gas storage filling and discharging port and the reserved plug-in port can be set on the side of the manhole inspection channel, instead of being set on the flange cover in the traditional way, eliminating the need for disassembly and installation of the filling and discharging pipelines and monitoring cables when the flange is disassembled, reducing the impact of the gas storage maintenance construction on the filling and discharging pipelines and monitoring cables, and greatly improving the efficiency of maintenance construction.

[0066] Example 2

[0067] A construction method for the manhole inspection channel structure of the compressed air energy storage artificial chamber gas storage reservoir described in the above-mentioned embodiment 1, the method comprising:

[0068] S1. Chamber excavation and support:

[0069] The longitudinal traffic tunnel 3, the blocking structure 2 and the gas storage reservoir 1 are excavated and supported in sequence. The traffic tunnel 3 and the blocking structure are only supported in the initial stage, and the gas storage reservoir 1 needs to be poured with secondary lining after the initial support is completed;

[0070] S2. Manhole inspection channel production and processing:

[0071] Through a specific large-scale machine, the steel plate is curled and welded to form two sections of ordinary straight pipe sections 4 and one section of straight pipe section with flange 7, and the ordinary straight pipe section is bent to form a curved pipe section 7. Bolt holes are drilled at the corresponding positions of the flange, and holes are drilled for reserved gas filling and discharge ports 8 and reserved wire insertion ports 9;

[0072] Among them, the steel pipe formed by S201 and curled steel plate has only one welding seam, and submerged arc automatic welding equipment is used to ensure the quality of the weld;

[0073] S3. Concrete pouring of the first layer of the blocking structure:

[0074] Pour the first layer of concrete for the plugging structure 2. The concrete is C30 micro-expansive concrete with a pouring thickness of 0.5m;

[0075] S4. Installation of operation and maintenance channel:

[0076] The connecting ends of the ordinary straight pipe section 4, the curved pipe section 6 and the straight pipe section with flange 7 are grooved. After the first layer of concrete reaches sufficient structural strength, the ordinary straight pipe section 4 and the curved pipe section 6 are hoisted, and welding construction is started after docking and positioning. Then the straight pipe section with flange 7 is hoisted, and the curved pipe section 6 and the straight pipe section with flange 7 are welded after docking and positioning.

[0077] Among them, when the S401 steel pipe end is grooved, a combination of U-shaped groove and V-shaped groove is adopted. In order to ensure the welding quality, the groove is made by mechanical processing and the groove surface is guaranteed to have a certain roughness;

[0078] S5. Layered pouring of blocking structure:

[0079] C30 micro-expansive concrete is used to cast the plugging structure in layers. The concrete vibration strength is strengthened at the interface between the plugging body and the initial support to reduce the casting pores. At the same time, the backfill grouting pipe is reserved and installed at the interface between the plugging structure and the initial support, especially at the top of the chamber, to facilitate subsequent backfill grouting.

[0080] S6. Concrete maintenance of plugging structure:

[0081] Regularly maintain the cast plugging structure 2 to avoid concrete cracking due to inadequate maintenance and ensure that the concrete reaches the expected strength;

[0082] S7, backfill grouting of plugging structure:

[0083] After the plugging structure 2 is poured, there may still be gaps at the junction of the plugging structure and the surrounding rock, especially at the top of the plugging structure and other locations where concrete pouring is inconvenient. These locations are backfilled and grouted through the backfill grouting pipe to form a backfill grouting body to fill the pores;

[0084] Among them, S701, the slurry for backfill grouting adopts micro-expansive cement slurry, the grouting pressure is 0.2~0.5MPa, the grouting pipe is mainly arranged on the top of the plugging structure, the annular and longitudinal spacing is 1m×1m, and the grouting construction is carried out after the concrete of the sealing structure reaches sufficient strength;

[0085] S8, flange cover installation, construction and commissioning:

[0086] Use a clean rag to thoroughly clean the mounting surfaces of the flange and flange cover, hoist the flange cover 10, and dock and position it with the flange, and use the bolt and nut assembly 11 to connect and fix the flange and flange cover;

[0087] Among them, S801, when installing the bolts, tighten the bolts step by step in a diagonal order, and use a torque wrench to tighten them according to the specified torque value to ensure that the tightening force of each bolt is uniform.

[0088] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of this patent.

Claims

1. The structure of the manhole inspection channel of the compressed air energy storage artificial chamber gas storage is characterized by: The structure includes: Gas storage (1); A traffic tunnel (3), wherein the traffic tunnel (3) and the gas storage reservoir (1) are arranged perpendicular to each other; A blocking structure (2) located at the junction of the gas storage reservoir (1) and the traffic tunnel (3); The ordinary straight pipe section (4), the curved pipe section (6), and the straight pipe section with flange (7) are connected in sequence; The ordinary straight pipe section (4) is close to the gas storage reservoir (1), and the straight pipe section with flange (7) is close to the traffic tunnel (3); A double-sided beveled welding connection end (5) is provided at the joints between the ordinary straight pipe section (4), the curved pipe section (6), and the straight pipe section with flange (7); A gas storage filling and discharging port (8) and a reserved plug-in port (9) are arranged on the side of the straight pipe section (6) with a flange plate extending to the traffic tunnel (3). The gas storage filling and discharging port (8) is arranged on the opposite side, and the reserved plug-in port (9) is arranged at the bottom of the maintenance passage to facilitate the subsequent protection of a steel plate at the bottom of the maintenance passage; A flange cover (10) is provided at the port of the traffic tunnel (3), and is installed by means of a bolt and nut assembly (11).

2. The structure of the manhole inspection channel of the compressed air energy storage artificial chamber gas storage according to claim 1 is characterized in that: The ordinary straight pipe section (4) is a circular steel pipe with an outer diameter of 1.0 to 1.8 mm and a wall thickness of 50 to 150 mm. One end of the ordinary straight pipe section (4) is flush with the blocking structure, and the other end is connected to the curved pipe section (6).

3. The structure of the manhole inspection channel of the compressed air energy storage artificial chamber gas storage according to claim 1 is characterized in that: The curved pipe section (6) is formed by bending an ordinary straight pipe section (4) by a specific large-scale machine. The inner and outer diameters of the curved pipe section (6) are consistent with those of the ordinary straight pipe section (4). The curved pipe section (6) is respectively connected to the ordinary straight pipe section (4) and the straight pipe section with flange (7).

4. The structure of the manhole inspection channel for the compressed air energy storage artificial chamber gas storage according to claim 1 is characterized in that: The flange cover (10) is a concave steel plate structure with the notch facing outwards, so that the force on the flange cover (10) is uniform; the center thickness of the flange cover (10) is 15 to 20 cm, and the edge thickness is 30 to 40 cm. The structure of thick edges and thin centers can effectively reduce the weight of the flange cover (10) and reduce the difficulty of disassembly and installation of the flange cover (10) during maintenance.

5. The structure of the manhole inspection channel of the compressed air energy storage artificial chamber gas storage according to claim 1 is characterized in that: Double-sided groove welding connection (5) Before welding, double-sided grooves are cut on the ends of the steel pipe to increase the surface area of ​​the welding connection and improve the welding connection performance.

6. The structure of the manhole inspection channel of the compressed air energy storage artificial chamber gas storage according to claim 1 is characterized in that: The manhole inspection channel is cast inside the plugging structure (2), the center line of the manhole inspection channel coincides with the center line of the plugging structure (2), the distance from the bottom plate of the manhole inspection channel to the bottom plate of the gas storage reservoir (1) is 0.5 m, and the two ends of the manhole inspection channel are respectively connected to the artificial chamber gas storage reservoir (1) and the traffic tunnel (3), so as to realize the entry and exit of personnel and the transportation of maintenance materials and maintenance equipment during the maintenance of the gas storage reservoir (1).

7. A construction method for a manhole inspection channel structure of a compressed air energy storage artificial chamber gas storage reservoir applied to any one of claims 1 to 6, characterized in that: The method includes: S1. Chamber excavation and support: The longitudinal traffic tunnel (3), the blocking structure (2) and the gas storage reservoir (1) are excavated and supported in sequence. The traffic tunnel (3) and the blocking structure are only initially supported, and the gas storage reservoir (1) needs to be poured with a secondary lining after the initial support is completed; S2. Manhole inspection channel production and processing: By using a specific large-scale machine, the steel plate is rolled and welded to form two sections of ordinary straight pipe (4) and one section of straight pipe with flange (7), and the ordinary straight pipe section is bent to form a curved pipe section (7). Bolt holes are drilled at the corresponding positions of the flange, and holes are drilled for reserved gas filling and discharge ports (8) and reserved wire insertion ports (9); Among them, the steel pipe formed by S201 and curled steel plate has only one welding seam, and submerged arc automatic welding equipment is used to ensure the quality of the weld; S3. Concrete pouring of the first layer of the blocking structure: Cast the first layer of concrete of the plugging structure (2), using C30 micro-expansive concrete with a casting thickness of 0.5m; S4. Installation of operation and maintenance channel: The connecting ends of the ordinary straight pipe section (4), the curved pipe section (6) and the straight pipe section with flange (7) are grooved, and after the first layer of concrete reaches sufficient structural strength, the ordinary straight pipe section (4) and the curved pipe section (6) are hoisted, and welding construction is started after docking and positioning, and then the straight pipe section with flange (7) is hoisted, and welding construction of the curved pipe section (6) and the straight pipe section with flange (7) is carried out after docking and positioning. Among them, when the S401 steel pipe end is grooved, a combination of U-shaped groove and V-shaped groove is adopted. In order to ensure the welding quality, the groove is made by mechanical processing and the groove surface is guaranteed to have a certain roughness; S5. Layered pouring of blocking structure: C30 micro-expansive concrete is used to cast the plugging structure in layers. The concrete vibration strength is strengthened at the interface between the plugging body and the initial support to reduce the casting pores. At the same time, the backfill grouting pipe is reserved and installed at the interface between the plugging structure and the initial support, especially at the top of the chamber, to facilitate subsequent backfill grouting. S6. Concrete maintenance of plugging structure: Regularly maintain the cast plugging structure (2) to prevent concrete cracking due to inadequate maintenance and ensure that the concrete reaches the expected strength; S7, backfill grouting of plugging structure: After the plugging structure (2) is poured, there may still be gaps at the interface between the plugging structure and the surrounding rock, especially at locations where it is inconvenient to pour concrete, such as the top of the plugging structure. These locations are backfilled and grouted through the backfill grouting pipe to form a backfill grouting body to fill the pores; Among them, S701, the slurry for backfill grouting adopts micro-expansive cement slurry, the grouting pressure is 0.2~0.5MPa, the grouting pipe is mainly arranged on the top of the plugging structure, the annular and longitudinal spacing is 1m×1m, and the grouting construction is carried out after the concrete of the sealing structure reaches sufficient strength; S8, flange cover installation, construction and commissioning: Use a clean rag to thoroughly clean the mounting surfaces of the flange and flange cover, hoist the flange cover (10), and align it with the flange, and use the bolt and nut assembly (11) to connect and fix the flange and flange cover; Among them, S801, when installing the bolts, tighten the bolts step by step in a diagonal order, and use a torque wrench to tighten them according to the specified torque value to ensure that the tightening force of each bolt is uniform.

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