A test device and method for surrounding rock and extreme load under compressed air energy storage cavern
By constructing a compressed air energy storage cavern test device with a multi-level variable stiffness surrounding rock simulation layer and a gradient reinforced concrete lining layer, and combining high-pressure gas and temperature control modules with a multi-field monitoring system, the problem of insufficient loading capacity and test applicability of existing devices under simulated complex surrounding rock conditions was solved, and test research under high-pressure temperature change combined working conditions was realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YUNLONG LAKE LAB OF DEEP UNDERGROUND SCI & ENG
- Filing Date
- 2026-05-14
- Publication Date
- 2026-06-12
AI Technical Summary
Existing compressed air energy storage underground cavern test devices are difficult to realistically simulate structural response under complex and changing surrounding rock conditions. They have limited loading capacity and are difficult to conduct test studies under combined high pressure and temperature change conditions. They also lack multi-field monitoring, which affects the practical engineering applicability of the test results.
A cavern structure system consisting of a multi-level variable stiffness surrounding rock simulation layer, a gradient reinforced concrete lining layer, and a steel lining sealing layer was constructed. Combined with a high-pressure gas loading module, an independent temperature control module, and a multi-field coupled monitoring system, independent application of pressure loads and temperature loads and multi-source response data acquisition were realized.
Simulates the structural response of complex changing surrounding rock under in-situ conditions, realizes the test under combined high pressure and temperature change conditions, reduces local stress concentration, provides multi-source response data, and provides a basis for the analysis of the coordinated deformation and interface force transmission law of surrounding rock-lining-sealing layer.
Smart Images
Figure CN122192953A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of underground space engineering and large-scale energy storage technology, specifically a test device and method for compressed gas energy storage cavern under variable surrounding rock and extreme loads. Background Technology
[0002] Compressed air energy storage underground caverns typically employ a composite structure consisting of surrounding rock, concrete lining, and a sealing layer to withstand the internal high-pressure gas load and achieve gas storage sealing. During operation, these structures are subject to not only gas pressure but also temperature variations and cyclic loads, making their stress, deformation, and interface force transmission issues quite complex.
[0003] Existing experimental studies on underground caverns for compressed air energy storage mostly employ indoor scaled-down models, homogeneous surrounding rock assumptions, or single structural forms, making it difficult to realistically simulate the structural response under complex changing surrounding rock conditions such as the interface between soft and hard rocks and abrupt changes in surrounding rock stiffness. Furthermore, in some existing experimental setups, pressure loading and temperature loading are difficult to control separately, hindering experimental research under combined high-pressure and temperature-changing conditions.
[0004] In addition, the loading capacity of existing test devices is usually limited, making it difficult to meet the test requirements under higher pressure levels. Furthermore, existing studies mostly use indoor small-scale models or numerical analysis methods, and the test scale differs significantly from actual underground engineering conditions. This can easily lead to deviations between boundary conditions, structural response, and long-term cyclic characteristics and actual conditions, thus affecting the applicability of test results to actual engineering projects.
[0005] Furthermore, existing technologies lack experimental devices that consider both structural design and multi-field monitoring, particularly for localized slippage at locations of abrupt changes in surrounding rock stiffness, interfacial stress concentration, and the collaborative working relationship between the surrounding rock, lining, and sealing layer. This hinders systematic research on the structural response of compressed gas storage caverns under complex operating conditions. Therefore, it is necessary to provide an experimental device and method for compressed gas storage caverns under varying surrounding rock conditions and extreme loads. Summary of the Invention
[0006] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.
[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a test device for compressed gas energy storage cavern under variable surrounding rock and extreme loads, comprising, The cavern structure system is constructed within the in-situ underground tunnel. The cavern structure system includes, from the outside to the inside, a multi-level variable stiffness surrounding rock simulation layer, a multi-level gradient reinforced concrete lining layer, and a steel lining sealing layer. A wedge-shaped pressure-bearing plug system is used to seal and anchor the tunnel opening. The extreme load loading system includes a high-pressure gas loading module and an independent temperature control module, which are connected to the tunnel through the wedge-shaped pressure-bearing plug system; The multi-field coupling monitoring system includes an external signal acquisition instrument and a group of monitoring sensors deployed at various levels of the device. The monitoring sensor group is connected to the signal acquisition instrument via a signal input line.
[0008] As a preferred technical solution for a test device for compressed gas storage cavern under variable surrounding rock and extreme loads, the multi-level variable stiffness surrounding rock simulation layer is divided along the axial direction into a soft rock section that is excavated and backfilled, a original rock section that retains the natural rock mass, and a hard rock section that is excavated and backfilled; the elastic modulus of the similar material filled in the soft rock section is 5 GPa to 10 GPa; and the elastic modulus of the similar material filled in the hard rock section is 18 GPa to 25 GPa.
[0009] As a preferred technical solution for a test device for compressed gas storage cavern under variable surrounding rock and extreme loads, the multi-level gradient reinforced concrete lining layer includes a first reinforcement section, a second reinforcement section, a third reinforcement section and a fourth reinforcement section along the axial direction; longitudinal steel bars and circumferential steel bars are arranged inside the concrete lining layer.
[0010] As a preferred technical solution for a test device for compressed gas storage cavern under varying surrounding rock and extreme loads, the reinforcement ratio of each reinforcement section varies in a stepwise manner along the axial direction, and the magnitude of the reinforcement ratio is negatively correlated with the elastic modulus of the simulated surrounding rock layer in the corresponding region.
[0011] As a preferred technical solution for a test device for compressed gas storage cavern under varying surrounding rock and extreme loads, the shear-resistant transition zone is set at the junction of stiffness abrupt changes between adjacent surrounding rock sections; the shear-resistant transition zone includes a locally thickened shear-resistant steel lining section and shear-resistant reinforcing bars embedded in the concrete lining layer.
[0012] As a preferred technical solution for a test device for compressed gas storage cavern under variable surrounding rock and extreme loads, the thickness of the shear-resistant steel lining section is 2 to 3 times that of the other conventional steel lining sections, and the connection between the shear-resistant steel lining section and the conventional steel lining section adopts a tapered gradual chamfer to achieve a smooth transition; the shear-resistant reinforcing bars in the shear-resistant transition zone are densely distributed along the circumferential direction and cross the stiffness change boundary section in the axial direction.
[0013] As a preferred technical solution for a test device for compressed gas energy storage cavern under variable surrounding rock and extreme loads, the high-pressure gas loading module includes a primary compressor, a gas pressure stabilizing device and a secondary compressor connected in sequence, and is connected to the internal cavity of the steel lining through the gas filling pipe and the gas venting pipe that penetrate the wedge-shaped pressure-bearing plug system.
[0014] As a preferred technical solution for a test device for compressed gas energy storage cavern under variable surrounding rock and extreme loads, the independent temperature control module includes a temperature control unit and its connected hot and cold fluid injection / output pipelines and hot and cold fluid circulation coils; the hot and cold fluid circulation coils are wound around the inner surface of the steel lining sealing layer.
[0015] As a preferred technical solution for a test device for compressed gas storage cavern under varying surrounding rock and extreme loads, the monitoring sensor group of the multi-field coupled monitoring system includes: Thermometers, barometers, and hygrometers are suspended inside the cavern. Pressure cell sensors are placed at the interface between the steel lining and the lining, and at the interface between the lining and the surrounding rock. Reinforcing bars connected in series with circumferential reinforcing bars; Acoustic emission sensors arranged inside the lining; And a multi-point displacement meter that penetrates radially into the surrounding rock.
[0016] This invention also discloses a method for a test device for compressed gas energy storage caverns under the aforementioned variable surrounding rock and extreme loads, including... S1. Segmented backfilling for reconstructed surrounding rock with variable stiffness; S2. Gradient lining construction, sealing layer and shear-resistant transition zone construction, and simultaneous implantation of sensor network; S3. Wedge-shaped pressure-bearing plug is cast, and the pipeline passes through the high-pressure sealing lead; S4.30MPa level high and low pressure and independent decoupled combination loading of hot and cold fluids; S5. Acquisition of multi-source heterogeneous entity data.
[0017] The beneficial effects of this invention are: This invention simulates the structural response of a compressed gas storage cavern in complex and changing surrounding rock under in-situ conditions by constructing a multi-level variable stiffness surrounding rock simulation layer, a gradient reinforced concrete lining layer, and a steel lining sealing layer. By setting up a high-pressure gas loading module and an independent temperature control module, pressure and temperature loads can be applied relatively independently, facilitating extreme combination condition tests. The addition of anti-shear transition zones at stiffness abrupt change locations helps mitigate local stress concentration and shear slip. Furthermore, the establishment of a multi-field coupled monitoring system provides multi-source response data, offering an experimental basis for analyzing the coordinated deformation and interface force transmission laws of the surrounding rock-lining-sealing layer. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a schematic diagram of the overall structure of the experimental device of the present invention; Figure 2 This is an enlarged view of the cavern structure system of the experimental device of the present invention; Figure 3 This is a cross-sectional view of the soft rock section of the cavern structure of the test device of the present invention; Figure 4 This is a cross-sectional view of the original rock section of the cavern structure of the experimental device of the present invention; Figure 5 This is a cross-sectional view of the hard rock section of the cavern structure of the test device of the present invention; Figure 6 This is a partially enlarged schematic diagram of the anti-shear transition zone structure in this invention; Figure 7 This is a diagram showing the cross-sectional layout of the multi-field coupling monitoring system of the present invention. Figure 8 This is a diagram showing the arrangement of the multi-field coupling monitoring sensors of the present invention; Figure 9 This is a diagram showing the arrangement of monitoring sensors inside the surrounding rock according to the present invention; Figure 10 This is a flowchart of the extreme load test method of the present invention.
[0019] Figure label: 100. Cavern structural system; 111. Soft rock section; 112. Original rock section; 113. Hard rock section; 120. Multi-grade gradient reinforced concrete lining layer; 121. First reinforcement section; 122. Second reinforcement section; 123. Third reinforcement section; 124. Fourth reinforcement section; 1211. Longitudinal reinforcement; 1212. Circumferential reinforcement; 1213. Shear-resistant transition zone reinforcement; 130. Steel lining sealing layer; 140. Shear-resistant transition zone; 211. Primary compressor; 212. Gas pressure stabilizing device; 213. Secondary compressor; 21 4. Inflation pipe; 215. Deflator pipe; 221. Temperature control unit; 222. Hot and cold fluid injection / output pipes; 223. Hot and cold fluid circulation coils; 300. Wedge-shaped pressure-bearing plug system; 410. Signal acquisition instrument; 420. Signal input line; 431. Acoustic emission sensor; 433. Pressure box sensor; 432. Rebar gauge; 434. Thermometer; 435. Barometer; 436. Hygrometer; 437. Multi-point displacement gauge; 441. Monitoring section one; 442. Monitoring section two; 443. Monitoring section three. Detailed Implementation
[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0021] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.
[0022] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.
[0023] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.
[0024] Example 1
[0025] Reference Figures 1-10 This embodiment provides a test device for compressed gas energy storage cavern under variable surrounding rock and extreme loads, including: The cavern structure system 100 is constructed inside the underground tunnel and consists of, from the outside to the inside, a multi-level variable stiffness surrounding rock simulation layer, a multi-level gradient reinforced concrete lining layer 120, and a steel lining sealing layer 130 responsible for seepage prevention and gas blocking; a shear-resistant transition zone 140 is set at the junction of stiffness abrupt changes between adjacent surrounding rock sections. The extreme load loading system includes a high-pressure gas loading module and an independent temperature control module, which are used to apply alternating gas pressure and temperature shocks independent of gas pressure changes to the interior of the cavern, respectively. The wedge-shaped pressure-bearing plug system 300 is sealed and anchored to the opening end of the tunnel to convert the high-pressure thrust inside the tunnel into radial lateral pressure on the surrounding rock mass; The multi-field coupling monitoring system includes an external signal acquisition unit 410 and a group of monitoring sensors deployed at various levels of the device.
[0026] Furthermore, the multi-level variable stiffness surrounding rock simulation layer is divided into three sections along the axial direction: the soft rock section 111, which is excavated and backfilled; the original rock section 112, which retains the natural rock mass; and the hard rock section 113, which is excavated and backfilled.
[0027] Preferably, the elastic modulus of the soft rock section 111 filled with a similar material is 5 GPa to 10 GPa; the elastic modulus of the hard rock section 113 filled with a similar material is 18 GPa to 25 GPa.
[0028] Furthermore, Figure 3 correspond Figure 7 A schematic diagram of the cross-sectional structure at monitoring section 441. Figure 4 correspond Figure 7 A schematic diagram of the cross-sectional structure at monitoring section 2, point 442. Figure 5 correspond Figure 7 A schematic diagram of the cross-sectional structure at monitoring section 3443.
[0029] Furthermore, the multi-grade gradient reinforced concrete lining layer 120 is subdivided into four or more reinforcement segments along the axial direction, including the first reinforcement segment 121, the second reinforcement segment 122, the third reinforcement segment 123, and the fourth reinforcement segment 124. It should be noted that the first reinforcement segment 121 is a high-reinforcement segment, the second reinforcement segment 122 is a medium-high reinforcement segment, the third reinforcement segment 123 is a medium reinforcement segment, and the fourth reinforcement segment 124 is a low-reinforcement segment. The degree of reinforcement of the reinforcement segment is negatively correlated with the elastic modulus of the rock segment, and each reinforcement segment spans two different rock segments. Similarly, two different reinforcement segments are set under each rock segment.
[0030] The multi-gradient reinforced concrete lining layer 120 is internally reinforced with longitudinal steel bars 1211 and circumferential steel bars 1212.
[0031] Preferably, the reinforcement ratio of each reinforcement section varies in a stepwise manner along the axial direction, and the magnitude of the reinforcement ratio is negatively correlated with the elastic modulus of the surrounding rock simulation layer in the corresponding area.
[0032] Furthermore, the shear-resistant transition zone 140 is set at the junction section where the stiffness changes abruptly between adjacent surrounding rock sections; the shear-resistant transition zone 140 includes a locally thickened shear-resistant steel lining section 131, and shear-resistant steel reinforcement 1213 embedded in the multi-grade gradient reinforced concrete lining layer 120.
[0033] Preferably, the thickness of the shear-resistant steel lining section is 2 to 3 times the thickness of the other conventional steel lining sections, and the connection between the shear-resistant steel lining section and the conventional steel lining section adopts a tapered gradual chamfer to achieve a smooth transition; the shear-resistant steel bars 1213 in the shear-resistant transition zone are densely distributed along the circumference and cross the stiffness change boundary section in the axial direction.
[0034] Furthermore, the high-pressure gas loading module includes a primary compressor 211, a gas pressure stabilizing device 212, and a secondary compressor 213 connected in sequence, and is connected to the internal cavity of the steel lining through an inflation pipe 214 and an venting pipe 215 that penetrate the wedge-shaped pressure-bearing plug system 300.
[0035] Furthermore, the independent temperature control module includes a temperature control unit 221 and its connected hot and cold fluid injection / output pipeline 222 and hot and cold fluid circulation coil 223; the hot and cold fluid circulation coil 223 is wound around the inner surface of the steel-lined sealing layer 130.
[0036] Furthermore, referring to Figure 8 The monitoring sensor group of the multi-field coupling monitoring system includes: Thermometer 434, barometer 435, and hygrometer 436 are suspended inside the cavern. Pressure cell sensor 433 is arranged at the interface between the steel lining and the lining and the interface between the lining and the surrounding rock; The number of reinforcing bars connected in series with the circumferential reinforcing bar 1212 is 432; Acoustic emission sensor 431 arranged inside the lining; And a multi-point displacement meter 437 that penetrates radially into the surrounding rock.
[0037] Multi-point displacement gauge 437 usage status reference Figure 9 Multiple sensors are installed along the circumference of the inner wall of the surrounding rock and extend radially into the inner wall of the surrounding rock for monitoring.
[0038] It should be noted that thermometer 434, barometer 435, and hygrometer 436 are installed in two sets: one set suspended above the surrounding rock and the other set below the surrounding rock, as shown in the reference. Figure 8 Collect data from multiple perspectives.
[0039] Preferably, the signal input lines 420 of each sensor are led out to the external signal acquisition instrument 410 through the stepped high-pressure sealed wire hole reserved in the wedge-shaped pressure-bearing plug system 300.
[0040] The rebar gauge 432 is connected in series with the circumferential rebar 1212 for monitoring purposes. This is existing technology and will not be described in detail here.
[0041] This embodiment utilizes an in-situ underground tunnel, such as an abandoned mine renovation project, to construct a large-scale test device for compressed air energy storage caverns under complex variations in surrounding rock and extreme load conditions. The total axial length of the device is set at 30 meters, and the diameter of the rough tunnel excavation is 7 meters.
[0042] 1. Refined spatial construction of variable stiffness surrounding rock and gradient lining In the construction of the cavern structure system 100, to simulate the spatial variability of deep rock masses, the test cavern was divided into three 10-meter-long sections along a 30-meter axis to reconstruct a multi-level variable stiffness surrounding rock simulation layer: 0-10m section: The original tunnel wall was widened by about 2 meters and backfilled with a low modulus similar material with an elastic modulus of 8GPa to form soft rock section 111.
[0043] Section 10-20m: The natural boundary of the tunnel is preserved. According to the survey, its elastic modulus is about 13GPa, forming the original rock section 112.
[0044] Section 20-30m: Excavation and backfilling were carried out, and a high-modulus similar material with an elastic modulus of 20GPa was poured to form hard rock section 113.
[0045] A multi-stage gradient reinforced concrete lining layer 120, with a radial thickness of 0.5 meters, was poured in sections adjacent to the inner wall of the simulated surrounding rock layer. The lining is internally reinforced with longitudinal steel bars 1211 and circumferential steel bars 1212, forming a framework. Based on the differences in the self-bearing capacity of the three types of surrounding rock, inverse proportional gradient reinforcement was implemented. Within the soft rock section 111, a first reinforced section 121 with a reinforcement ratio of 3.0% and a second reinforced section 122 with a reinforcement ratio of 2.5% are each 5 meters long. Within the original rock section 112, a third reinforcement section 123 with reinforcement ratios of 2.5% and 2.0% is sequentially installed; Within the hard rock section 113, a fourth reinforcement section 124 with reinforcement ratios of 2.0% and 1.5% is provided.
[0046] Subsequently, a 10mm thick steel lining sealing layer 130 is fully laid and welded inside the multi-gradient reinforced concrete lining layer 120 to achieve absolute impermeability of high-pressure gas.
[0047] 2. Special design of the anti-shear transition zone structure Addressing the engineering challenge of uneven settlement and shear failure easily triggered by abrupt changes in surrounding rock stiffness at 10m and 20m, this embodiment innovatively incorporates a double-layered shear-resistant transition zone 140: Inside the outer concrete, dense shear-resistant transition zone steel bars 1213 are cross-tied at the interface to cross the soft and hard interface and tie the lining; in the inner steel lining, the thickness of the local steel lining at the interface is smoothly and gradually increased to 2 to 3 times that of the conventional section, and the connection between the thickened steel lining and the conventional steel lining adopts a tapered bevel gradually chamfered to resist local shear deformation and eliminate stress concentration under alternating loads.
[0048] 3.30MPa extreme load decoupling loading and through-wall sealing The extreme load loading system achieves complete decoupling of the thermo-mechanical boundary.
[0049] The high-pressure gas loading module adopts a stepped pressurization method. The external gas is initially pressurized by the first-stage compressor 211, buffered by the gas pressure stabilizing device 212, and then pressurized to the maximum ultimate pressure of 30MPa by the second-stage compressor 213. The high-pressure gas is injected into the gas chamber through the gas filling pipe 214 that runs through the wedge-shaped pressure-bearing plug system 300, and achieves rapid alternating pressure relief through the gas release pipe 215.
[0050] Meanwhile, the temperature control unit 221 of the independent temperature control module pumps cold and hot fluid into the cold and hot fluid circulation coil 223, which is densely distributed around the steel lining sealing layer 130, through the cold and hot fluid injection / output pipeline 222, and independently applies extreme cold and hot temperature shocks under a constant 30MPa air pressure.
[0051] The wedge-shaped pressure-bearing plug system 300 cast at the opening utilizes its tapered structure that expands from the inside out to generate a structural self-locking effect to resist the huge axial thrust generated by 30MPa.
[0052] 4. Targeted multi-field coupled three-dimensional multi-dimensional monitoring network To accurately reveal the collaborative bearing and load sharing mechanism of different stiffness boundaries under ultra-high pressure, a multi-field coupled monitoring system has established a cross-scale measured data chain based on specific spatial topological logic: In this embodiment, along the tunnel axis, six main monitoring sections are set at the axial center of each of the six 5-meter-long sections with different reinforcement ratios. Each monitoring sensor group is arrayed based on these six main monitoring sections. Fluid boundary capture: Thermometer 434, barometer 435, and hygrometer 436 are suspended inside the air chambers corresponding to each monitoring section to capture transient fluid boundaries within the chambers; Interlayer decoupling stress capture: At each main monitoring section, pressure cell sensors 433 are embedded in an array at equal intervals along the circumference at the steel lining-lining interface and the lining-surrounding rock interface to accurately capture the total stress of interlayer thrust and thermal decoupling. Structural resistance and damage capture: Reinforcing bars 432 were arranged in series on the circumferential reinforcing bars 1212 of each main monitoring section to obtain the differences in tensile yield evolution paths of six different gradient linings; and a three-dimensional array of acoustic emission sensors 431 was pre-embedded inside the lining to locate microcrack propagation. Deep attenuation capture: At each monitoring section, multiple displacement gauges 437 are installed radially into the deep part of the surrounding rock to monitor the nonlinear spatial attenuation of the extreme pressure of 30MPa in three types of variable stiffness surrounding rock.
[0053] All the above signal input lines 420 are connected into a bus bundle after being shielded and armored by high voltage. The bundle is led out to the external signal acquisition instrument 410 through the stepped high-voltage sealed wire hole reserved in the wedge-shaped pressure-bearing plug system 300.
[0054] This invention provides a 30MPa-level stepped high-pressure loading and independent temperature control system, filling the gap in the device for forward-looking in-situ verification of future ultra-high pressure LRC gas storage facilities; it constructs a composite structure of variable stiffness surrounding rock and gradient reinforcement, and innovatively sets a shear-resistant transition zone composed of thickened steel lining and cross-interface shear-resistant steel bars in the abrupt change zone, which significantly improves the engineering reliability of the device under extreme displacement, and provides a structural foundation for subsequent experimental revelation of the core load sharing mechanism.
[0055] Furthermore, based on this, high-fidelity in-situ tests and multi-dimensional monitoring networks were used to accurately obtain macroscopic and microscopic response data of the structure, and to thoroughly investigate the coordinated deformation law and load sharing mechanism of "surrounding rock-lining-sealing layer" under ultra-high pressure alternating working conditions.
[0056] Specifically, the present invention also provides a method for conducting extreme load tests on compressed air energy storage caverns using the above-mentioned test apparatus, further comprising the following steps: S1. Segmented backfilling for reconstructed surrounding rock with variable stiffness; S2. Gradient lining construction, sealing layer and shear-resistant transition zone construction, and simultaneous implantation of sensor network; S3. Wedge-shaped pressure-bearing plug is cast, and the pipeline passes through the high-pressure sealing lead; S4.30MPa level high and low pressure and independent decoupled combination loading of hot and cold fluids; S5. Acquisition of multi-source heterogeneous entity data.
[0057] The collected data were imported into a numerical model for digital twin inversion analysis of the coordinated deformation law and load sharing mechanism of the surrounding rock-lining-sealing layer.
[0058] Furthermore, the digital twin inversion analysis includes: a) Establish a three-layer composite numerical model of surrounding rock-lining-sealing layer based on the actual structure of the test device; b) Import the pressure, displacement, strain, temperature and acoustic emission data of each monitoring section into the numerical model according to the loading sequence; c) Correct the segmented mechanical parameters of the surrounding rock, the force transmission parameters of the interlayer interface, and the lining damage parameters by iterative inversion; d) When the error between the measured value and the calculated value meets the preset threshold, output the deformation coordination relationship of each layer of the structure, the interface load transfer path and the sharing ratio; e) Identify the main control response mechanisms of the soft-hard rock interface zone, shear-resistant transition zone, and different gradient reinforcement sections based on the multi-condition inversion results.
[0059] In the invention method, a cavern is excavated from the original rock mass, and on this basis, a cavity adapted to the hard rock section and the soft rock section is excavated, and rock material is backfilled to make it present a layered structure with different elastic moduli, forming a variable stiffness surrounding rock cavern. During this process, a pressure box sensor 433 is simultaneously implanted.
[0060] Subsequently, a multi-grade gradient reinforced concrete lining layer 120 was laid inside the tunnel, and steel bars 432 were inserted. Shear-resistant steel lining sections 131 were added at the connection of different reinforcement layers. A thermometer 434, a barometer 435, and a hygrometer 436 were installed inside the tunnel. A multi-point displacement meter 437 was installed by making radial openings in the side wall of the tunnel.
[0061] Finally, a wedge-shaped pressure-bearing plug is poured at the opening of the cavern, and a slot is reserved for pipes and leads to pass through, and then the corresponding pipes and leads are configured.
[0062] After the structure was laid, it was tested by independent decoupled combination loading of high and low pressure and hot and cold fluids at 30MPa level. The sensors collected data, which was then analyzed by the system.
[0063] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.
[0064] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A test device for compressed gas energy storage cavern under varying surrounding rock and extreme loads, characterized in that: include, The cavern structure system (100) is constructed in the in-situ underground tunnel. The cavern structure system (100) includes a multi-level variable stiffness surrounding rock simulation layer, a multi-level gradient reinforced concrete lining layer (120) and a steel lining sealing layer (130) arranged sequentially from the outside to the inside. A wedge-shaped pressure-bearing plug system (300) is sealed and anchored to the opening end of the tunnel; The extreme load loading system includes a high-pressure gas loading module and an independent temperature control module, wherein the high-pressure gas loading module and the independent temperature control module pass through the wedge-shaped pressure-bearing plug system (300) and are connected to the tunnel; The multi-field coupling monitoring system includes an external signal acquisition instrument (410) and a group of monitoring sensors deployed at each level of the device. The monitoring sensor group is connected to the signal acquisition instrument (410) via a signal input line (420).
2. The test device for compressed gas energy storage cavern under varying surrounding rock and extreme loads according to claim 1, characterized in that: The multi-level variable stiffness surrounding rock simulation layer is divided along the axial direction into a soft rock section (111) for excavation and backfilling, a original rock section (112) for retaining natural rock mass, and a hard rock section (113) for excavation and backfilling. The elastic modulus of the soft rock section (111) filled with similar materials is 5 GPa to 10 GPa. The elastic modulus of the hard rock section (113) filled with similar materials is 18 GPa to 25 GPa.
3. The test device for compressed gas energy storage cavern under variable surrounding rock and extreme loads according to claim 2, characterized in that: The multi-level gradient reinforced concrete lining layer (120) includes a first reinforcement section (121), a second reinforcement section (122), a third reinforcement section (123) and a fourth reinforcement section (124) along the axial direction; the multi-level gradient reinforced concrete lining layer (120) is provided with longitudinal steel bars (1211) and circumferential steel bars (1212).
4. The test device for compressed gas energy storage cavern under variable surrounding rock and extreme loads according to claim 3, characterized in that: The reinforcement ratio of each reinforcement section varies in a stepwise manner along the axial direction, and the magnitude of the reinforcement ratio is negatively correlated with the elastic modulus of the surrounding rock simulation layer in the corresponding area.
5. The test device for compressed gas energy storage cavern under variable surrounding rock and extreme loads according to claim 4, characterized in that: A shear-resistant transition zone (140) is provided at the junction of the stiffness abrupt change of adjacent surrounding rock sections; the shear-resistant transition zone (140) includes a locally thickened shear-resistant steel lining section (131) and shear-resistant steel reinforcement (1213) embedded in the multi-grade gradient reinforced concrete lining layer (120).
6. The test device for compressed gas energy storage cavern under varying surrounding rock and extreme loads according to claim 5, characterized in that: The thickness of the shear-resistant steel lining section is 2 to 3 times that of the other conventional steel lining sections, and the connection between the shear-resistant steel lining section and the conventional steel lining section adopts a tapered gradual chamfer to achieve a smooth transition; the shear-resistant steel bars (1213) of the shear-resistant transition zone are densely distributed in the circumferential direction and cross the stiffness change boundary section in the axial direction.
7. The test device for compressed gas energy storage cavern under varying surrounding rock and extreme loads according to claim 6, characterized in that: The high-pressure gas loading module includes a first-stage compressor (211), a gas pressure stabilizing device (212), and a second-stage compressor (213) connected in sequence, and is connected to the internal cavity of the steel lining through an inflation pipe (214) and an venting pipe (215) that pass through the wedge-shaped pressure-bearing plug system (300).
8. The test device for compressed gas energy storage cavern under varying surrounding rock and extreme loads according to claim 7, characterized in that: The independent temperature control module includes a temperature control unit (221) and its connected hot and cold fluid injection / output pipeline (222) and hot and cold fluid circulation coil (223); the hot and cold fluid circulation coil (223) is wound around the inner surface of the steel lining sealing layer (130).
9. The test device for compressed gas energy storage cavern under varying surrounding rock and extreme loads according to claim 8, characterized in that: The monitoring sensor group of the multi-field coupling monitoring system includes: Thermometer (434), barometer (435) and hygrometer (436) are suspended inside the cavern. Pressure cell sensors (433) are arranged at the interface between the steel lining and the lining and the interface between the lining and the surrounding rock. Reinforcing bar (432) connected in series with the circumferential reinforcing bar (1212); Acoustic emission sensor (431) arranged inside the lining. And a multi-point displacement meter that penetrates radially into the surrounding rock (437).
10. A method for a test device for a compressed gas storage cavern under varying surrounding rock and extreme loads as described in any one of claims 1 to 9, characterized in that: S1. Segmented backfilling for reconstructed surrounding rock with variable stiffness; S2. Gradient lining construction, sealing layer and shear-resistant transition zone construction, and simultaneous implantation of sensor network; S3. Wedge-shaped pressure-bearing plug is cast, and the pipeline passes through the high-pressure sealing lead; S4.30MPa level high and low pressure and independent decoupled combination loading of hot and cold fluids; S5. Acquisition of multi-source heterogeneous entity data.