Arrangement method for roadway junctions for compressed air energy storage in abandoned mine roadway space

Abstract

The present invention relates to the technical field of mine roadway utilization. Provided is an arrangement method for roadway junctions for compressed air energy storage in abandoned mine roadway space. The method comprises: using a geophysical prospecting method to perform preliminary prospecting on a roadway junction to determine the stress and deformation states of roadway surrounding rock at the roadway junction, so as to determine the range of elastic-plastic areas; dividing the roadway junction into a plurality of areas; digging equilateral triangle-shaped recesses in the two sides of the roadways; using grouting and grouting anchor cables to reinforce the roadway surrounding rock; providing air pipes in the middle portions of the roadways, and simultaneously providing three-way valves in roadway intersection areas, and wrapping the outer side of each air pipe with a protection layer; and, according to area division, performing filling and sealing. The method uses area-based grouting reinforcement treatment to effectively reduce the treatment difficulty and improve the bearing capacity of roadways, and uses communication pipes to connect a plurality of roadways so as to ensure smooth air circulation. In addition, roadway junctions configured by using the method have better sealing tightness and stability, thereby providing convenience for compressed air energy storage.

Description

A method for arranging tunnel intersections for compressed gas energy storage in abandoned shaft and tunnel spaces Technical Field

[0001] The present invention relates to the technical field of shaft and tunnel utilization, and in particular provides a method for arranging tunnel intersections for compressed gas energy storage in abandoned shaft and tunnel spaces. Background Art

[0002] Renewable energy sources (such as wind and solar energy) are abundant, widely distributed, renewable, and environmentally friendly, making them ideal alternative energy sources. However, the uncertainty and uncontrollability of wind and photovoltaic power generation mean that grid-connected wind turbines cannot meet the requirements for stability, continuity, and adjustability. The constant fluctuations in output power can easily impact the grid, making it difficult for dispatchers to effectively plan wind power generation. This, in turn, increases system backup power, peak-shaving capacity, and operating costs, threatening the safe and stable operation of the system. Compressed air energy storage technology can effectively address the intermittent and unstable nature of clean energy generation. Its dual regulation function can further enhance the peak-shaving capacity of the grid. Using compressed air energy storage technology can be an effective means of regulating power supply and reusing abandoned mines.

[0003] With the further advancement of coal mine production reduction, a large number of abandoned shafts and tunnels are left in abandoned mines. The rational use of underground space, avoiding waste of space resources, and realizing the reuse of abandoned mines are issues that need to be addressed nowadays. Using abandoned shafts and tunnels as compressed air energy storage space and building compressed air energy storage power stations can, on the one hand, effectively utilize a large amount of abandoned underground space; on the other hand, the development of compressed air energy storage technology also further promotes the development of renewable energy. In the operation of compressed air energy storage power stations, abandoned shafts and tunnels play an important role as storage space for high-pressure air. The key issue in its construction is the sealing of abandoned shafts and tunnels when used as gas storage space and the stability of the surrounding rock. Technical issues

[0004] In the prior art, Chinese patent CN106593486A discloses a steel tube concrete composite support for tunnel intersections. This invention connects a support frame and a bridging frame via a docking device and injects concrete slurry to form a steel tube concrete structure for integral support. This method fails to consider the impact of components such as casing and grouting ports on the overall strength of the composite support during the treatment process. Furthermore, this method fails to consider the sealing issues at tunnel intersections, and therefore cannot guarantee the sealing of tunnel intersections. This makes it unsuitable for tunnel intersection treatment for compressed gas energy storage in abandoned shafts and tunnels.

[0005] Chinese patent CN 203374284U discloses a fully enclosed cross-section masonry support system for soft rock tunnels. This system utilizes anchor rods and a reinforced mesh shotcrete layer as the primary support. The inner masonry layer forms a horseshoe-shaped composite support. After the inverted arch is cast, the gangue is backfilled to form a fully enclosed, complete support structure. While this support method creates a sealed support space, its sealing performance is poor, making it unsuitable for compressed gas energy storage in abandoned tunnels.

[0006] The existing methods for managing tunnel intersections are generally combined support and anchor mesh support. These methods provide support for tunnel intersections and play a good supporting and protective role; however, they do not take into account the sealing requirements when the tunnel is used as a gas storage. Because there is no certain treatment for the sealing of the tunnel intersections, they are not yet suitable for the management of tunnel intersections for compressed gas energy storage in abandoned shaft and tunnel spaces. Technical Solutions

[0007] In order to achieve the management of the intersection position of the tunnel, improve the bearing capacity of the tunnel, and ensure the airtightness and stability of the intersection position, the present invention provides a method for arranging the tunnel intersection for compressed gas energy storage in abandoned shaft and tunnel space. The specific technical solution is as follows.

[0008] A method for arranging tunnel intersections for compressed gas energy storage in abandoned shaft and tunnel spaces, characterized in that the steps include:

[0009] S1. Conduct preliminary exploration of tunnel intersections using geophysical methods to determine the stress and deformation state of the tunnel surrounding rock at the tunnel intersections and the extent of the elastic-plastic zone of the tunnel surrounding rock.

[0010] S2. Divide the roadway intersection area into multiple areas;

[0011] S3. Dig equilateral triangle grooves on both sides of the roadway;

[0012] S4. Grouting the surrounding rock of the tunnel and constructing grouting anchor reinforcement;

[0013] S5. Install ventilation ducts in the middle of the lanes, install three-way valves at the intersection of the lanes, and wrap the ventilation ducts with a protective layer;

[0014] S6. Fill and seal according to the area division.

[0015] Preferably, the geophysical exploration method includes a DC resistivity method, an electromagnetic survey method and a gravity survey method.

[0016] Preferably, the side length of the equilateral triangle is 0.3-0.7 times the width of the lane, and the groove and the lane space form a truncated cone cavity structure.

[0017] Preferably, the tunnel surrounding rock grouting is specifically to perform grouting reinforcement on the plastic failure zone of the tunnel surrounding rock, and the grouting anchors are to fill the cracks and pores in the elastic zone of the tunnel surrounding rock.

[0018] Preferably, the protective layer includes a first PE film layer, a steel mesh layer and a second PE film layer, and the first PE film layer, the steel mesh layer and the second PE film layer are arranged in sequence from inside to outside.

[0019] It is also preferred that the filling and sealing process includes: arranging steel mesh, setting up slurry retaining plates, filling and grouting with concrete, and removing the slurry retaining plates after the slurry solidifies.

[0020] It is also preferred that the filling and sealing is performed by grouting in sequence according to the multiple areas divided in step S2.

[0021] It is also preferred that when the intersection area is divided, each area does not contain an intersection, and the intersection is located at the boundary of adjacent areas.

[0022] It is further preferred that a valve is provided on the ventilation pipe, and the ventilation pipe is a hollow steel pipe.

[0023] It is further preferred that the arrangement method of the tunnel intersections for compressed gas energy storage in abandoned shaft and tunnel spaces can also be applied to sharp intersections or bull nose intersections. Beneficial effects

[0024] The beneficial effect of the method for arranging tunnel intersections for compressed gas energy storage in abandoned shaft and tunnel spaces provided by the present invention is that the method divides the areas in detail at the tunnel intersections, and reinforces and manages the tunnels in sequence by dividing the areas, thereby improving the bearing capacity of the tunnels and ensuring the stability of the tunnel surrounding rocks. At the same time, the tunnels are connected by two-way pipes to ensure smooth flow of gas. The method reduces the pressure of the surrounding rocks at the tunnel intersections by making the ventilation pipe the main part that bears the gas pressure, effectively avoiding surrounding rock damage, and the method is applicable to the treatment of various types of tunnel intersection positions, has a wide range of applicability, and has good management effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a flow chart showing a method for arranging roadway intersections for compressed gas energy storage in abandoned shaft spaces;

[0026] Figure 2 is a schematic diagram of a roadway intersection;

[0027] Figure 3 is a schematic diagram of the roadway intersection area division;

[0028] Figure 4 is a schematic diagram of the groove construction at the intersection of the roadway;

[0029] Figure 5 is a schematic diagram of tunnel grouting construction;

[0030] Figure 6 is a schematic diagram of the intersection after treatment;

[0031] In the figure: 1-tunnel, 2-tunnel surrounding rock, 3-tunnel intersection, 4-groove, 5-grouting anchor, 6-grouting hole, 7-elastic zone of surrounding rock, 8-plastic zone of surrounding rock, 9-pipeline, 10-valve. Modes for Carrying Out the Invention

[0032] 1 to 6 , a specific embodiment of a method for arranging tunnel intersections for compressed gas energy storage in abandoned shaft and tunnel spaces provided by the present invention will be described.

[0033] The existing methods for managing tunnel intersections are generally combined support and anchor mesh support. These methods all provide support for tunnel intersections and play a good supporting and protective role; however, these methods do not take into account the sealing requirements when the tunnel is used as a gas storage, and therefore cannot make certain treatments for the sealing of the tunnel intersections. They are not suitable for the management of tunnel intersections for compressed gas energy storage in abandoned shaft and tunnel spaces.

[0034] A method for arranging tunnel intersections for compressed gas energy storage in abandoned shaft and tunnel spaces, characterized in that the steps include:

[0035] S1. Conduct preliminary exploration of tunnel intersections using geophysical methods to determine the stress and deformation state of the tunnel surrounding rock at the tunnel intersections and the extent of the elastic-plastic zone of the tunnel surrounding rock.

[0036] Geophysical exploration methods include DC resistivity, electromagnetic exploration, and gravity exploration. Preliminary exploration of tunnel intersections using these methods is then verified through drilling to clarify the stress and deformation state of the tunnel surrounding rock at these intersections and to determine the extent of its elastic-plastic zone. This provides a theoretical basis for subsequent grouting reinforcement of the plastic failure zone of the tunnel surrounding rock and the initial treatment of the elastic core zone with grouting anchor cables.

[0037] S2. Divide the roadway intersection area into multiple areas;

[0038] When dividing the intersection area, each area does not contain an intersection, and the intersection is at the junction of adjacent areas.

[0039] As shown in Figure 3, in this embodiment, the intersection of the tunnels is divided into six areas, that is, the area at the intersection of the tunnels is divided into different areas according to the principle of not including bifurcation points, and the complex tunnels at the intersection of the tunnels are simplified into a single simple space. Each area does not contain intersections to facilitate subsequent management.

[0040] S3. Dig equilateral triangle grooves on both sides of the roadway;

[0041] The sides of the equilateral triangles are 0.3-0.7 times the roadway width, and the grooves and the roadway space form a truncated cone cavity structure. Grooves are dug on both sides of each roadway in an irregular equilateral triangle shape, with the sides 0.3-0.7 times the roadway width. Field verification shows that this ratio facilitates construction, stabilizes the structure, and achieves better results. The grooves, combined with the existing roadway space, form a truncated cone cavity structure. This equilateral triangle shape effectively increases the bond between the roadway surrounding rock and the grouting filling within the roadway, ensuring roadway stability, while also facilitating construction.

[0042] S4. Grouting the surrounding rock of the tunnel and constructing grouting anchor reinforcement;

[0043] The tunnel surrounding rock grouting is specifically to carry out grouting reinforcement on the plastic failure zone of the tunnel surrounding rock, and the grouting anchor cable fills the cracks and pores in the elastic zone of the tunnel surrounding rock. To reinforce the tunnel surrounding rock, the grouting holes are used to carry out grouting reinforcement on the plastic failure zone of the tunnel surrounding rock, so as to enhance the strength and integrity of the tunnel surrounding rock and improve the bonding force; at the same time, the grouting anchor cable is arranged to fill the cracks and pores in the elastic core zone of the tunnel surrounding rock to form an anchoring section, and the pull rod is anchored in the rock and soil layer to give full play to the anchoring effect of the anchor cable and enhance the tensile performance of the tunnel surrounding rock; in this way, the preliminary treatment of the tunnel surrounding rock is achieved and the stability of the tunnel surrounding rock is ensured.

[0044] S5. Install ventilation ducts in the middle of the lanes, install three-way valves at the intersection of the lanes, and wrap the ventilation ducts with a protective layer;

[0045] The ventilation pipe is provided with a valve and is a hollow steel pipe. The protective layer includes a first PE film layer, a steel mesh layer and a second PE film layer, which are arranged in sequence from the inside out.

[0046] In this embodiment, a ventilation pipe is set up in the center of each tunnel. The pipe is a hollow steel pipe. At the same time, in areas 1, 4, and 6 where the tunnels intersect, the pipes in three directions are connected by three-way valves; and valves are arranged on the side of areas 1, 4, and 6 away from the tunnel intersection to control the flow of gas.

[0047] S6. Fill and seal according to the area division.

[0048] The filling and sealing process includes: arranging the steel mesh, setting up the slurry retaining plate, filling and grouting the concrete, and removing the slurry retaining plate after the slurry solidifies. The filling and sealing is grouting in sequence according to the multiple areas divided in step S2.

[0049] First, a steel mesh is arranged in area 1 to enhance the tensile and compressive properties of the filling in the area.

[0050] Then, slurry retaining plates are arranged on both sides of area 1, and grouting ports are reserved; valves are installed on the grouting ports, and the opening and closing of the grouting ports can be controlled by the valves.

[0051] Then carry out grouting filling in area 1 through the grouting port and inject concrete slurry into it. Grouting can be stopped only after the grouting pressure is stably increased to the set value to ensure that the slurry completely fills the filling area.

[0052] The slurry retaining plate can be removed only after the slurry in the grouting area has solidified and stabilized.

[0053] Repeat the steps of "laying out the steel mesh, placing the grouting plate, and injecting the concrete slurry" for each area in the same manner as in area 1 above. If one end of the area being filled is already filled, there is no need to place the grouting plate at that end. Grouting can be carried out from the other end to ensure the continuity of the filling.

[0054] Finally, once all areas are filled and stable, a complete filling volume is formed, ensuring that the tunnel intersection meets both stability and sealing requirements. By implementing regional grouting reinforcement and using interconnecting pipes to connect different tunnels, the bearing capacity of the surrounding rock at the tunnel intersection is effectively increased, the pressure on the surrounding rock at the tunnel intersection is reduced, and the stability of the surrounding rock at the tunnel intersection is increased. This method also ensures smooth gas flow, facilitates control of gas flow, and achieves stronger airtightness and greater economy.

[0055] In addition, the arrangement method of the tunnel intersection points for compressed gas energy storage in abandoned shaft and tunnel space can also be applied to tunnel intersection types such as sharp intersection points or bull nose intersection points.

[0056] This method uses regional grouting reinforcement and uses connecting pipes to connect multiple tunnels. At the intersection of tunnels in abandoned shafts and tunnels, preliminary treatment of the surrounding rock is first carried out, followed by regional grouting reinforcement. On the one hand, it can significantly reduce the difficulty of treatment, and on the other hand, it can effectively improve the bearing capacity of the tunnel and increase the stability of the surrounding rock at the tunnel intersection. In the preliminary treatment of the surrounding rock at the intersection of tunnels in abandoned shafts and tunnels, shallow grouting and deep grouting anchor cable treatment methods are also used to ensure the stability of the tunnel surrounding rock. Using connecting pipes to connect multiple tunnels at the intersection of tunnels in abandoned shafts and tunnels can ensure smooth gas flow, and installing valves makes it easier to control the direction of gas flow. On the other hand, the ventilation pipe becomes the main part that carries the gas pressure, reducing the pressure borne by the surrounding rock at the tunnel intersection, thereby effectively avoiding damage to the surrounding rock.

[0057] This method is universal in its application to the treatment of tunnel intersections in the utilization of compressed gas energy storage in abandoned shaft and tunnel spaces, and is also applicable to other types of tunnel intersections.

[0058] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A method for arranging the intersection of abandoned shaft and lane spaces for compressed gas energy storage, characterized in that the steps include: S1. Use geophysical detection methods to conduct preliminary detection of the tunnel intersections, determine the stress and deformation state of the tunnel surrounding rock at the tunnel intersections, and determine the elastic-plastic zone range of the tunnel surrounding rock; S2. Divide the roadway intersection area into multiple areas; S3. Dig equilateral triangle grooves on both sides of the tunnel; S4. Grouting the surrounding rock of the tunnel and constructing grouting anchor reinforcement; S5. Set up a ventilation pipe in the middle of the tunnel, set up a three-way valve at the intersection of the tunnels, and wrap a protective layer outside the ventilation pipe; S6. Fill and seal according to the area division.

2. The method for arranging the intersection of abandoned shaft and lane spaces for compressed gas energy storage according to claim 1 is characterized in that: The geophysical exploration methods include direct current resistivity method, electromagnetic exploration method and gravity exploration method.

3. The method for arranging the intersection of abandoned shaft and lane spaces for compressed gas energy storage according to claim 1 is characterized in that: The side length of the equilateral triangle is 0.3-0.7 times the width of the lane, and the groove and the lane space form a truncated cone cavity structure.

4. The method for arranging the intersection of abandoned shaft and lane spaces for compressed gas energy storage according to claim 1 is characterized in that: The tunnel surrounding rock grouting specifically involves grouting reinforcement of the plastic failure zone of the tunnel surrounding rock, and the grouting anchor fills the cracks and pores in the elastic zone of the tunnel surrounding rock.

5. The method for arranging the intersection of abandoned shaft and lane spaces for compressed gas energy storage according to claim 1 is characterized in that: The protective layer comprises a first PE film layer, a steel mesh layer and a second PE film layer, and the first PE film layer, the steel mesh layer and the second PE film layer are arranged in sequence from the inside to the outside.

6. The method for arranging the intersection of abandoned shaft and lane spaces for compressed gas energy storage according to claim 1 is characterized in that: The filling and sealing process includes: arranging steel mesh, setting slurry retaining plates, filling and grouting with concrete, and removing the slurry retaining plates after the slurry solidifies.

7. The method for arranging the intersection of abandoned shaft and lane spaces for compressed gas energy storage according to claim 1 is characterized in that: The filling and sealing is performed by grouting and filling in sequence according to the multiple areas divided in step S2.

8. The method for arranging the intersection of abandoned shaft and lane spaces for compressed gas energy storage according to claim 1 is characterized in that: When dividing the intersection area, each area does not contain intersections, and the intersections are located at the junctions of adjacent areas.

9. The method for arranging the intersection of abandoned shaft and lane spaces for compressed gas energy storage according to claim 1, characterized in that: A valve is arranged on the ventilation pipe, and the ventilation pipe is a hollow steel pipe.

10. The method for arranging the intersection of abandoned shaft and lane spaces for compressed gas energy storage according to claim 1, characterized in that: The method for arranging the intersection points of abandoned shaft and lane spaces for compressed gas energy storage is applied to the intersection points through the tip or the intersection points with the bull nose.

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