Underground high-pressure cavern structure based on joint stress and construction method thereof

Abstract

The application discloses a kind of underground high-pressure cavern structures based on joint stress and construction method thereof, belong to energy storage system technical field, can solve the problem of existing including compressed air energy storage underground high-pressure cavern and water passing high-pressure tunnel etc. in the process of storing and releasing energy, supporting effect is weak, the problem of low utilization efficiency of deep surrounding rock. The structure includes: cavern surrounding rock, including excavation formed loose circle and deep surrounding rock located outside the loose circle;Multiple pressure transmission anchor rods, one end is provided with a pressure receiving end plate, the other end is provided with an anchor head plate;The one end of pressure transmission anchor rod with pressure receiving end plate is placed in deep surrounding rock;Grouting layer is arranged inside the loose circle;Lining layer is arranged inside the grouting layer;Anchor head plate is placed in the lining layer.The application is suitable for underground gas storage and other water passing high-pressure tunnels.

Description

Technical Field

[0001] This invention relates to an underground high-pressure cavern structure based on combined stress and its construction method, belonging to the field of energy storage system technology. Background Technology

[0002] Compressed air energy storage refers to the process of compressing air into a storage tank using electricity, storing it, and then releasing the high-pressure air to generate electricity when needed. The actual excavation profile of a compressed air storage tank is often larger than the design cross-section, necessitating backfill grouting between the design lining and the actual excavation profile. During energy storage, the internal air pressure of the storage tank can reach 7–12 MPa, and the lining and backfill grout are in a compressed state. During energy release, the lining and backfill grout are in a relaxed state. Similarly, underground high-pressure tunnels experience excessive internal water pressure when water flows through them, and the internal water pressure decreases when the tunnel is emptied. Under the cyclic loading of energy storage and release, the lining and backfill grout exhibit a brittle state, making them highly susceptible to fatigue damage, which weakens the support effect of the lining and backfill grout. Currently, the utilization rate of compressed air energy storage and deep surrounding rock in underground high-pressure tunnels is low, making it difficult to utilize the original rock bearing capacity of the deep surrounding rock. Summary of the Invention

[0003] This invention provides an underground high-pressure cavern structure based on combined stress and its construction method, which can solve the problems of weakened support effect and low utilization efficiency of deep surrounding rock in existing compressed air energy storage underground high-pressure caverns during energy storage and release.

[0004] On one hand, the present invention provides an underground high-pressure cavern structure based on combined stress, the structure comprising:

[0005] The surrounding rock of the cavern includes the loosened zone formed by excavation and the deep surrounding rock located outside the loosened zone;

[0006] Multiple pressure-transmitting anchor bolts, each with a pressure-bearing end plate at one end and an anchor head plate at the other end; the end of the pressure-transmitting anchor bolt with the pressure-bearing end plate is placed in the deep surrounding rock.

[0007] The grouting layer is located inside the loosening ring;

[0008] A lining layer is disposed inside the grouting layer; the anchor head plate is placed inside the lining layer.

[0009] Optionally, the structure further includes:

[0010] A sealing layer is disposed on the inner side of the lining layer.

[0011] Optionally, the pressure-bearing end plate and the anchor head plate are respectively vertically welded to both ends of the pressure-transmitting anchor rod.

[0012] Optionally, the anchor head plate is welded to the reinforcing bars within the lining layer.

[0013] Optionally, the size of the anchor head plate is larger than the size of the pressure-bearing end plate.

[0014] On the other hand, the present invention provides a construction method for any of the above-described underground high-pressure cavern structures based on combined stress, the method comprising:

[0015] S1. Excavate the surrounding rock of the cavern to form a loosening zone;

[0016] S2. Connect a pressure-bearing end plate to the first end of each pressure-transmitting anchor rod, and place the first end of the pressure-transmitting anchor rod into the deep surrounding rock outside the loosening ring;

[0017] S3. Connect an anchor head plate to the second end of each pressure-transmitting anchor rod, and cast the second end of the pressure-transmitting anchor rod and the anchor head plate at its end together into reinforced concrete to form a lining layer; wherein, the first end and the second end are the two opposite ends of the pressure-transmitting anchor rod;

[0018] S4. A grouting layer is formed between the loosening ring and the lining layer.

[0019] Optionally, S2 specifically includes:

[0020] S21. Drill holes around the loosening ring to form multiple holes along the radial direction of the loosening ring; the holes extend into the deep surrounding rock outside the loosening ring; each hole corresponds to a pressure-transmitting anchor rod.

[0021] S22. Connect a pressure-bearing end plate to the first end of each pressure-transmitting anchor rod, and place the first end of the pressure-transmitting anchor rod into the corresponding hole.

[0022] Optionally, prior to S3, the method further includes:

[0023] S5. Install a sleeve on the pressure-transmitting anchor rod located inside the loosening ring;

[0024] Specifically, S4 is:

[0025] Backfilling and grouting are carried out between the loosened ring and the lining layer to form a grouting layer.

[0026] Optionally, S3 specifically includes:

[0027] S31. Connect an anchor head plate to the second end of each of the pressure-transmitting anchor rods, and weld reinforcing bars onto the anchor head plate;

[0028] S32. The second end of the pressure-transmitting anchor rod and its end anchor head plate are cast together in reinforced concrete to form a lining layer.

[0029] Optionally, after S4, the method further includes:

[0030] S6. A sealing layer is made on the inner side of the lining layer.

[0031] The beneficial effects that this invention can produce include:

[0032] (1) The underground high-pressure cavern structure and its construction method based on combined stress provided by this invention are applicable to the reinforcement of lining structures for underground compressed air storage facilities and some water-carrying high-pressure tunnels. During lining construction, pressure-transmitting anchors are installed, which are tied or welded together with reinforcing bars before pouring. During backfilling and grouting, sleeves are installed on the pressure-transmitting anchors exposed in the surrounding rock to provide a safety reserve for backfilling and grouting. Since the pressure-transmitting anchors connect the deep surrounding rock, the loosened zone, and the lining, they also serve to reinforce the surrounding rock and provide support, thus improving the overall performance of the underground high-pressure cavern.

[0033] (2) The underground high-pressure cavern structure and its construction method based on combined stress provided by this invention have the anchor head plate of the pressure-transmitting anchor rod tied or welded to the lining reinforcement, and the pressure-bearing end plate of the pressure-transmitting anchor rod in contact with the deep surrounding rock. The mechanical transmission effect is obvious during the operation of the underground high-pressure cavern. At the same time, the stress is transmitted into the surrounding rock through the pressure-transmitting anchor rod, making great use of the original rock bearing capacity of the deep surrounding rock, with clear physical and mechanical concepts; and the deformation of the lining under high pressure is effectively controlled by the pressure-transmitting anchor rod that penetrates deep into the surrounding rock, thereby preventing lining cracking. It has the effects of reducing costs and increasing efficiency, reducing the amount of lining reinforcement, and optimizing the lining thickness. Attached Figure Description

[0034] Figure 1 A schematic diagram of an underground high-pressure cavern structure based on combined stress provided for an embodiment of the present invention.

[0035] List of components and reference numerals:

[0036] 1. Surrounding rock of the cavern; 2. Actual excavation cross section; 3. Loosening ring; 4. Hole; 5. Pressure bearing end plate; 6. Pressure transmitting anchor bolt; 7. Design cross section; 8. Sleeve; 9. Grouting layer; 10. Anchor head plate; 11. Reinforcing steel; 12. Lining layer; 13. Sealing layer; 14. Air pressure; 15. Load; 16. Deep surrounding rock. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the embodiments, but the present invention is not limited to these embodiments.

[0038] This invention provides an underground high-pressure cavern structure based on combined stress, such as... Figure 1 As shown, the structure includes:

[0039] The surrounding rock of the cavern 1 includes the loosened zone 3 formed by excavation and the deep surrounding rock 16 located outside the loosened zone 3.

[0040] During construction, the surrounding rock 1 of the cavern is excavated first, which can form the actual excavation section 2 and at the same time form the loosening zone 3.

[0041] Multiple pressure-transmitting anchor rods 6 are provided with a pressure-bearing end plate 5 at one end and an anchor head plate 10 at the other end; the end of the pressure-transmitting anchor rod 6 with the pressure-bearing end plate 5 is placed in the deep surrounding rock 16 outside the loosening ring 3.

[0042] In practical applications, the pressure-bearing end plate 5 and the anchor head plate 10 are respectively vertically welded to both ends of the pressure-transmitting anchor rod 6.

[0043] To insert the end of the pressure-transmitting anchor 6 with the bearing end plate 5 into the deep surrounding rock 16 outside the loosening ring 3, it is first necessary to drill holes in the surrounding rock according to the actual excavation section 2, forming multiple holes 4 along the radial direction of the loosening ring 3. The diameter of the holes 4 is larger than that of the bearing end plate 5. Then, the bearing end plate 5 is welded to one end of the pressure-transmitting anchor 6. After welding, the pressure-transmitting anchor 6 with the bearing end plate 5 is driven into the holes 4. It should be noted that the length of the pressure-transmitting anchor 6 must be greater than the loosening ring 3 of the surrounding rock 1 of the cavern to ensure that the end of the pressure-transmitting anchor 6 with the bearing end plate 5 can penetrate deeply into the deep surrounding rock 16 outside the loosening ring 3.

[0044] In this embodiment of the invention, the material, thickness, shape, and size of the pressure-bearing end plate 5 and the anchor head plate 10 are not limited, and those skilled in the art can make settings according to actual conditions. In practical applications, the pressure-bearing end plate 5 and the anchor head plate 10 can be set as circular steel plates with a thickness of 1 to 2 cm, and the size of the anchor head plate 10 is larger than the size of the pressure-bearing end plate 5.

[0045] The present invention does not limit the number of pressure-transmitting anchor bolts 6, and those skilled in the art can set the number according to the actual situation. In practical applications, multiple pressure-transmitting anchor bolts 6 can be evenly distributed around the loosening ring 3 along the radial direction of the loosening ring 3.

[0046] Grouting layer 9 is located inside the loosening ring 3.

[0047] During construction, a certain length of pressure-transmitting anchor rod 6 needs to be reserved on the inner side of the actual excavation section 2. A sleeve 8 is installed on the pressure-transmitting anchor rod 6 within the reserved length for backfilling and grouting construction to form a grouting layer 9 and the designed section 7. The reserved length should be included within the designed section 7.

[0048] Lining layer 12 is set inside grouting layer 9; anchor head plate 10 is placed inside lining layer 12.

[0049] Anchor head plate 10 is welded to steel bar 11 inside lining layer 12.

[0050] Specifically, an anchor head plate 10 can be welded to the other end of the pressure-transmitting anchor rod 6. Note that the anchor head plate 10 is welded to the reinforcing steel bar 11 inside the lining layer 12. The pressure-transmitting anchor rod 6 with the anchor head plate 10 is cast together in reinforced concrete to form the lining layer 12.

[0051] Furthermore, the structure also includes:

[0052] The sealing layer 13 is disposed inside the lining layer 12.

[0053] After the above structure is completed, the sealing layer 13 needs to be constructed to ensure that the high-pressure cavern structure does not leak gas when storing gas under the action of air pressure 14 during normal operation.

[0054] Under the action of air pressure 14, the underground high-pressure cavern structure provided by the present invention transmits the load to the deep surrounding rock 16 through the pressure-transmitting anchor rod 6 with anchor head plate 10 and pressure-bearing end plate 5, thus playing a role in joint force bearing.

[0055] The underground high-pressure cavern structure based on combined stress provided by this invention is suitable for underground compressed air storage facilities and the reinforcement of lining structures in some high-pressure tunnels. During lining construction, pressure-transmitting anchor rods 6 are installed, bound or welded to reinforcing bars 11 before pouring. During backfilling and grouting, sleeves 8 are installed on the exposed portions of the pressure-transmitting anchor rods 6 to provide a safety reserve. Because the pressure-transmitting anchor rods 6 connect the deep surrounding rock 1, the loosened ring 3, and the lining, they also reinforce the surrounding rock 1 and provide support, thus improving the overall performance of the underground high-pressure cavern.

[0056] Another embodiment of the present invention provides a construction method for an underground high-pressure cavern structure based on combined stress as described above, the method comprising:

[0057] S1. Excavate the surrounding rock 1 of the cavern to form a loosening zone 3.

[0058] Specifically, excavating the surrounding rock 1 of the cavern can form an actual excavation section 2, and at the same time form a loosening zone 3 of the surrounding rock 1 of the cavern.

[0059] S2. Connect the pressure-bearing end plate 5 to the first end of each pressure-transmitting anchor 6, and place the first end of the pressure-transmitting anchor 6 into the deep surrounding rock 16 outside the loosening ring 3.

[0060] Specifically, it includes:

[0061] S21. Drill holes in the surrounding rock around the loosening ring 3 to form multiple holes 4 along the radial direction of the loosening ring 3; the holes 4 penetrate into the deep surrounding rock 16 outside the loosening ring 3; the holes 4 correspond one-to-one with the pressure transmission anchor rods 6.

[0062] S22. Connect the pressure-bearing end plate 5 to the first end of each pressure-transmitting anchor rod 6, and place the first end of the pressure-transmitting anchor rod 6 into the corresponding hole 4.

[0063] S3. Connect an anchor head plate 10 to the second end of each pressure-transmitting anchor rod 6, and cast the second end of the pressure-transmitting anchor rod 6 and the anchor head plate 10 at its end together into reinforced concrete to form a lining layer 12; wherein, the first end and the second end are the two opposite ends of the pressure-transmitting anchor rod 6.

[0064] Specifically, it includes:

[0065] S31. Connect an anchor head plate 10 to the second end of each pressure-transmitting anchor rod 6, and weld a steel bar 11 onto the anchor head plate 10;

[0066] S32. The second end of the pressure-transmitting anchor rod 6 and the anchor head plate 10 at its end are cast together in reinforced concrete to form a lining layer 12.

[0067] Furthermore, prior to S3, the method also includes:

[0068] S5. Install a sleeve 8 on the pressure-transmitting anchor rod 6 located inside the loosening ring 3.

[0069] S4. Create a grouting layer 9 between the loosening ring 3 and the lining layer 12.

[0070] Specifically, backfilling and grouting are carried out between the loosened ring 3 and the lining layer 12 to form a grouting layer 9.

[0071] Furthermore, after S4, the method further includes:

[0072] S6. A sealing layer 13 is made on the inside of the lining layer 12.

[0073] The construction method for underground high-pressure cavern structures based on combined stress provided by this invention binds or welds the anchor head plate 10 of the pressure-transmitting anchor 6 to the lining reinforcement 11. The bearing end plate 5 of the pressure-transmitting anchor 6 contacts the deep surrounding rock 16, effectively bearing the load 15 from the deep surrounding rock 16, resulting in significant mechanical transmission during the operation of the underground high-pressure cavern. Simultaneously, the stress is transferred into the deep surrounding rock 16 through the pressure-transmitting anchor 6, maximizing the original rock bearing capacity of the deep surrounding rock 16, with a clear physical and mechanical concept. Furthermore, the deformation of the lining under high pressure 14 is effectively controlled by the pressure-transmitting anchor 6 extending deep into the surrounding rock 16, thereby preventing lining cracking. This method achieves cost reduction and efficiency improvement, reduces the amount of lining reinforcement, and optimizes the lining thickness.

[0074] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A high-pressure underground cavern structure based on combined stress, characterized in that, The structure includes: The surrounding rock of the cavern includes the loosened zone formed by excavation and the deep surrounding rock located outside the loosened zone; Multiple pressure-transmitting anchor rods, each with a pressure-bearing end plate at one end and an anchor head plate at the other end; the end of the pressure-transmitting anchor rod with the pressure-bearing end plate is placed in the deep surrounding rock; the pressure-bearing end plate and the anchor head plate are respectively vertically welded to both ends of the pressure-transmitting anchor rod; a sleeve is fitted on the pressure-transmitting anchor rod located inside the loosening ring; The grouting layer is located inside the loosening ring; A lining layer is disposed inside the grouting layer; the anchor head plate is placed inside the lining layer; the anchor head plate is welded to the reinforcing steel in the lining layer; the grouting layer is formed by backfilling grouting between the loosening ring and the lining layer.

2. The structure according to claim 1, characterized in that, The structure also includes: A sealing layer is disposed on the inner side of the lining layer.

3. The structure according to claim 1, characterized in that, The size of the anchor head plate is larger than the size of the pressure-bearing end plate.

4. A construction method for an underground high-pressure cavern structure based on combined stress according to any one of claims 1 to 3, characterized in that, The method includes: S1. Excavate the surrounding rock of the cavern to form a loosening zone; S2. Connect a pressure-bearing end plate to the first end of each pressure-transmitting anchor rod, and place the first end of the pressure-transmitting anchor rod into the deep surrounding rock outside the loosening ring; S3. Connect an anchor head plate to the second end of each pressure-transmitting anchor rod, and cast the second end of the pressure-transmitting anchor rod and the anchor head plate at its end together into reinforced concrete to form a lining layer; wherein, the first end and the second end are the two opposite ends of the pressure-transmitting anchor rod; S4. A grouting layer is formed between the loosened ring and the lining layer; Prior to S3, the method further includes: S5. Install a sleeve on the pressure-transmitting anchor rod located inside the loosening ring; Specifically, S4 is: Backfilling and grouting are carried out between the loosened ring and the lining layer to form a grouting layer.

5. The method according to claim 4, characterized in that, S2 specifically includes: S21. Drill holes around the loosening ring to form multiple holes along the radial direction of the loosening ring; the holes extend into the deep surrounding rock outside the loosening ring; each hole corresponds to a pressure-transmitting anchor rod. S22. Connect a pressure-bearing end plate to the first end of each pressure-transmitting anchor rod, and place the first end of the pressure-transmitting anchor rod into the corresponding hole.

6. The method according to claim 4, characterized in that, S3 specifically includes: S31. Connect an anchor head plate to the second end of each of the pressure-transmitting anchor rods, and weld reinforcing bars onto the anchor head plate; S32. The second end of the pressure-transmitting anchor rod and its end anchor head plate are cast together in reinforced concrete to form a lining layer.

7. The method according to claim 4, characterized in that, Following S4, the method further includes: S6. A sealing layer is made on the inner side of the lining layer.

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