Test device and test method for simulating water sealing performance and stability of underground water-sealed oil depot under earthquake load based on vibration table

Abstract

The invention discloses a test device and method for simulating water sealing performance and stability of an underground water-sealed oil depot under an earthquake load based on a vibrating table, and relates to the technical field of underground water-sealed oil depots in geotechnical engineering. The test device comprises a model box, a similar material, a water curtain system, a water tank, an underground water level control device and an oil storage chamber, the model box is composed of a main body steel frame, a transparent observation panel, a side water permeable plate, a bottom water permeable plate and a bottom connecting plate. The similar material is paved on the bottom permeable plate, and the water curtain system and the oil storage cavern are sequentially buried in the similar material; side water tanks are defined by the two sides of the model box through the side water permeable plates, the underground water level control devices are installed in the side water tanks, and the bottom water permeable plates are supported by the supporting columns to form bottom water tanks. The test device is specially designed for a vibration table test, can accurately control the underground water level, the water pressure of a water curtain and the oil quantity of a cavity, can simulate the seepage-stress coupling effect, and provides support for research on water sealing performance and stability and optimization of engineering design in an oil depot earthquake.

Description

Technical Field

[0002] This invention relates to the field of underground water-sealed oil depot technology in geotechnical engineering, specifically a test device and test method for the water-sealing performance and stability of underground water-sealed oil depots under simulated seismic loads using a shaking table. Background Technology

[0003] An underground water-sealed oil depot is an underground engineering facility that uses groundwater pressure to achieve sealed oil storage. Its core principle is to excavate a cavern in the rock mass below the stable groundwater level, so that the pressure of the surrounding fissure water is always higher than the pressure of the oil inside the cavern, thereby forming a natural barrier to prevent leakage.

[0004] As a crucial strategic energy storage facility, the safe and stable operation of underground water-sealed oil depots is of paramount importance to ensuring energy supply and national energy security. In practical engineering scenarios, earthquakes, as a common natural disaster, can easily cause deformation of the surrounding rock of the oil depot caverns, sudden changes in pore water pressure, and disturbances in the seepage field, thereby threatening the sealing performance of the water-sealing system and the overall stability of the oil depot, leading to catastrophic consequences such as oil leaks. Therefore, conducting research on the relevant performance of underground water-sealed oil depots under seismic loading is of utmost importance.

[0005] Currently, numerical simulation methods are mainly used to study the impact of earthquakes on underground water-sealed oil depots. Mathematical models are established to simulate and analyze the stress, seepage, and other behaviors of the oil depots under seismic loads. However, the results of numerical simulations depend on the assumptions of the model parameters, and experimental data are lacking to verify the accuracy of the simulation results.

[0006] Currently, some existing similar model tests of underground water-sealed oil depots only consider the seepage field and do not simultaneously consider the synergistic simulation of the seepage field and stress field, thus failing to reproduce the seismic response characteristics under actual water-sealed conditions.

[0007] Therefore, there is an urgent need to construct experimental devices and methods that can simulate the seepage-stress coupling of underground water-sealed oil depots under seismic loading, so as to improve the reliability of seismic performance assessment of oil depots and provide a scientific basis for engineering design. Summary of the Invention

[0008] The purpose of this invention is to provide a test apparatus and method for testing the water-sealing performance and stability of underground water-sealed oil depots under seismic loads using a shaking table, aiming to: The acceleration, stress, and pore water pressure response of the surrounding rock of an underground water-sealed oil depot under simulated seismic loading; The failure mechanism of water seal system under seismic load is revealed, such as sudden change in seepage flow and failure of water pressure balance; This provides experimental basis and optimization parameters for the seismic design of underground water-sealed oil depots.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides an experimental device for testing the water-sealing performance and stability of an underground water-sealed oil depot under seismic load simulation using a shaking table. The device includes: a model box, similar materials, an oil storage chamber, a water curtain system, and a groundwater level control device. The structural design and specific configuration of each component are as follows: The similar material is laid in layers inside the model box. Its physical and mechanical parameters meet similar conditions to the surrounding rock of the actual oil depot. The purpose is to realistically reproduce the mechanical and seepage characteristics of the actual surrounding rock through a scaled-down model. A water curtain system and an oil storage cavern are arranged sequentially inside the similar material to simulate the spatial relationship between underground oil storage and water curtain protection.

[0010] The model box includes a main steel frame, a transparent observation panel, a permeable plate, and a bottom connecting plate. These components together form the basic load-bearing and observation framework for the experiment.

[0011] The main steel frame of the model box is a rigid support structure, welded together from five steel plates on the left, right, front, back, and bottom. A rectangular opening is provided in the middle of the front steel plate to ensure that the model box does not deform or loosen during the vibration table test, and to avoid interference from the deformation of the frame itself. The transparent observation panel is attached to the inside of the front steel plate of the steel frame, and its size is slightly larger than the rectangular opening. The joints are filled with shock-resistant sealant and covered with waterproof membrane. The panel is marked with a scale corresponding to the oil storage cavern area, which is used to observe the oil level in the oil storage cavern and the seepage of similar materials.

[0012] The permeable plate includes a side permeable plate and a bottom permeable plate: the side permeable plate is provided with side permeable plate permeable holes and has side permeable plate connection holes. It is first initially positioned with the main steel frame of the model box by bolts through the connection holes, and then welded and reinforced with the inner side of the steel frame along the four edges to achieve horizontal water replenishment; the bottom permeable plate is provided with bottom permeable plate permeable holes, and a bottom permeable plate support column is provided below it. The two ends of the support column are welded and fixed to the bottom permeable plate and the main steel frame of the model box, respectively, which not only supports the bottom permeable plate to prevent deformation caused by pressure of similar materials, but also reserves space to form a bottom water tank.

[0013] The bottom connecting plate is located below the main steel frame of the model box, and has multiple bottom connecting holes for rigidly connecting the model box to the vibration table surface with high-strength bolts.

[0014] The water tank includes a side water tank, a bottom water tank, and a side water tank baffle plate: the side water tank is formed by the side permeable plate and the main steel frame of the model box, and is used to store water; the side water tank baffle plate is located at the top of the side water tank and can move vertically along the slide rail with the slider to prevent water from overflowing during vibration; the bottom water tank is located between the bottom permeable plate and the main steel frame of the model box, and is connected to the side water tank through the permeable holes of the side permeable plate to form a complete groundwater boundary condition, and works with the side permeable plate to achieve uniform water replenishment from the side and bottom.

[0015] The preferred embodiment of the test device for the water-sealing performance and stability of an underground water-sealed oil depot under seismic load simulation based on a shaking table is that the oil storage cavern includes a main body of the oil storage cavern and oil supply, oil discharge and drainage devices. A water collection tank is located at the bottom of the oil storage cavern to collect seepage water within the cavern. The main body of the oil storage cavern has a straight-walled arched cross-section, consistent with the cross-sectional shape of an actual oil depot cavern. It is formed by using a pre-set mold when similar materials are laid in layers. The side of the tank near the main steel frame of the model box is closed, while the other side is attached to a transparent observation panel. A detachable transparent cavern cover is provided on the transparent observation panel opposite the oil storage cavern, facilitating the installation and disassembly of internal components of the oil storage cavern. The transparent cavern cover has an oil inlet, an oil outlet, and a drainage outlet. The drainage outlet is connected to the water collection tank via a seepage drainage pipe, which is equipped with a flow meter to discharge the seepage water in the water collection tank and to quantify the seepage flow rate. A submersible pump is located above the water collection tank and is connected to the oil outlet via an oil outlet pipe to extract oil from the cavern. The oil inlet is located above the oil outlet and is connected to the main body of the oil storage cavern via an oil inlet pipe. The oil inlet pipe is also connected to an oil supply pump and an oil storage tank for injecting oil into the cavern.

[0016] The preferred embodiment of the test device for the water-sealing performance and stability of an underground water-sealed oil depot under seismic load simulation based on a shaking table is that the water curtain system includes a water curtain tunnel, water curtain orifices, and a water curtain pressure control device. The water curtain tunnel is arranged perpendicular to the axis of the oil storage chamber, with a straight-walled circular arch cross-section. It is formed by embedding pre-set molds when similar materials are laid in layers. The water curtain tunnel is equipped with multiple water curtain tunnel permeable holes and water curtain tunnel inlets. The purpose of the permeable holes is to allow the water curtain water to permeate evenly into the similar materials. The water inlets are used to connect to the water curtain supply pipe. The water curtain holes are composed of porous PVC thin tubes and are arranged at the lowest row of water curtain tunnel permeable holes on the side plate of the water curtain tunnel to further refine the permeation range of the water curtain water and simulate a real water curtain system. The water curtain pressure control device includes a water curtain supply pipe, a water curtain pressure regulating valve, a water curtain booster pump, and a water curtain system storage tank. The water curtain supply pipe is connected to the water curtain tunnel through the water curtain tunnel inlet. The water curtain system storage tank is connected to the water curtain booster pump and the water curtain pressure regulating valve in sequence, and finally connected to the water curtain supply pipe. The booster pump provides stable water pressure, and the pressure regulating valve precisely controls the water injection pressure in the water curtain tunnel.

[0017] The preferred embodiment of the test device for the water-sealing performance and stability of an underground water-sealed oil depot under earthquake load simulation based on a shaking table is that the underground water level control device includes a slide rail, a water level sensor, a controller, a water level control pump, a pressure stabilizing valve, a water supply pipe, a water outlet tap, and an underground water level storage tank. The slide rail is installed on the side of the main steel frame of the model box inside the side water tank by slide rail fixing bolts, and a slider is installed on the slide rail; the water level sensor is connected to the slide rail through the slider, and the water baffle of the side water tank is installed on the upper part of the slider, located above the water level sensor, and moves vertically along the slide rail with the slider; the water level line is marked inside the side water tank, and different groundwater levels can be set by moving the slider; the controller is connected to the water level sensor through the sensor data line to receive water level data in real time and determine whether the water level in the tank has reached the set value; the inlet of the water level control pump is connected to the groundwater storage tank, and the outlet is connected to the pressure stabilizing valve; one end of the water supply pipe is connected to the pressure stabilizing valve, and the other end is connected to the water tap, which is placed inside the side water tank through a small hole on the water baffle of the side water tank; when the water level in the side water tank is lower than the set height of the water level sensor, the controller triggers the water level control pump to start, and water is added to the tank through the water tap; when the water level reaches the set height of the water level sensor, the controller shuts off the water level control pump to achieve automatic maintenance of the groundwater level.

[0018] A test method for the water-sealing performance and stability of an underground water-sealed oil depot under seismic loading using a shaking table, implemented using the aforementioned test apparatus, includes the following steps: S1, Assembly Model Box Clean the inside of the main steel frame of the model box and the transparent observation panel to prevent impurities from affecting the quality of similar material paving; at the same time, ensure that the transparent panel is free of stains so as not to interfere with subsequent observations, and check the welding integrity of the main steel frame of the model box. Confirm that the permeable holes of the side permeable plate and the bottom permeable plate are unobstructed. Connect the side permeable plate to the main steel frame of the model box through the connecting holes of the side permeable plate. Fix the bottom permeable plate support column and the bottom permeable plate. Weld and reinforce the contact points between the side permeable plate, the bottom permeable plate and the inner side of the main steel frame of the model box at the four edges. Install the slide rail in the side water tank. Inject a small amount of water into the side water tank and observe whether the water flows into the bottom water tank through the permeable holes of the side permeable plate. After checking that there is no leakage at each joint, proceed to the next step. The transparent observation panel is attached to the inside of the front steel plate of the main steel frame, and the joints are filled with shock-resistant sealant and covered with waterproof membrane. Connect the model box to the vibration table surface with bolts through the bottom connection holes on the bottom connection plate.

[0019] S2. Based on the physical and mechanical parameters of the surrounding rock of the actual underground water-sealed oil depot, the target parameters of the model materials are calculated according to the similarity ratio. Similar materials are prepared by using "aggregate, binder, regulator and solvent". An orthogonal test scheme is designed to conduct material similarity mix ratio test. Then, parameters such as permeability coefficient, uniaxial compressive strength and elastic modulus are tested. The optimal mix ratio is selected by comparing the target parameters to meet the physical and mechanical parameters of the surrounding rock of the underground water-sealed oil depot in the actual project.

[0020] S3. Initially assemble the water curtain system, check whether the water permeable holes and water curtain holes in the water curtain tunnel are unobstructed, check whether the water curtain pressure control device is working properly, eliminate blockages or equipment failures in the water curtain system, and ensure that the water curtain water can be supplied stably and evenly during the test.

[0021] S4. Mark the installation positions of the water curtain system and the oil storage cavern inside the main steel frame of the model box. First, lay out some similar materials in layers to the design height of the oil storage cavern, then put in the main mold of the oil storage cavern and fix it.

[0022] S5. Continue to lay similar materials in layers to the design height of the water curtain system. After connecting the water curtain tunnels, water curtain holes, and water curtain supply pipes, arrange them in a direction perpendicular to the axial direction of the oil storage cavern. Since the water curtain tunnels and water curtain holes are arranged inside the similar materials, the excavation step is eliminated. They can be directly arranged by embedding the molds, which can accurately guarantee their scaled geometric shape and spatial position according to the similarity theory.

[0023] S6. According to the pre-arranged sensor layout diagram, when similar materials are laid to the predetermined position, accelerometers, stress sensors and pore water pressure sensors are arranged, and sensor cables are led out from the top and connected to the data acquisition instrument.

[0024] S7. After each layer of similar material is laid, it is compacted with a loading plate. The layer-by-layer laying and compaction steps are repeated until the similar material fills to the design height.

[0025] S8. Remove the transparent cavern cover plate and carefully pull out the main mold of the oil storage cavern. This experiment directly studies the operation stage of the water-sealed cavern and does not involve the excavation step. Therefore, the oil storage cavern is directly generated by the mold, retaining the cavern structure that meets the requirements of the operation stage.

[0026] S9. Arrange a water collection tank at the bottom of the main body of the oil storage cavern. Connect the drain outlet to the water collection tank through a seepage drainage pipe and install a flow meter on the seepage drainage pipe. Connect the oil inlet to the main body of the oil storage cavern through an oil inlet pipe. Connect the oil inlet pipe to the oil supply pump and the oil storage tank. Place the submersible pump above the water collection tank and connect it to the oil outlet through an oil outlet pipe. Install a transparent cavern cover plate onto the transparent observation panel and seal it to prevent leakage.

[0027] S10. Connect the water curtain pressure regulating valve, water curtain booster pump, and water curtain system storage tank to the water curtain supply pipe to complete the final installation of the water curtain system and form a complete water curtain supply system.

[0028] S11. Fix the water level sensor and the side water tank baffle plate to the slide rail on the inner wall of the side water tank using a slider. Connect the controller to the water level sensor through the sensor data line. Connect the other end of the controller to the water level control pump switch. Connect the inlet of the water level control pump to the underground water storage tank and the outlet to the pressure stabilizing valve. Connect one end of the water supply pipe to the pressure stabilizing valve and the other end to the water tap. Place the water tap inside the side water tank through a small hole on the side water tank baffle plate to complete the installation of the underground water level control device.

[0029] S12. Add water to the side water tank. The water flows into the bottom water tank through the permeable holes of the side permeable plate. Adjust the initial groundwater level using the water level control pump and water level sensor. After the similar material is saturated with water, adjust the opening of the water curtain pressure regulating valve to set the initial water curtain tunnel pressure. Inject oil into the main body of the oil storage cavern through the oil inlet pipe. Control the thickness of the water cushion layer at the bottom of the main body of the oil storage cavern through the drain outlet to bring the model to the initial state of the test.

[0030] S13. Arrange a high-speed camera on the outside of the transparent observation panel, and adjust the lens angle so that the lens is perpendicular to the transparent observation panel to ensure that the seepage interface can be clearly captured.

[0031] S14. Turn on the high-speed camera, calibrate the sensor data acquisition accuracy, and ensure that the data acquisition of acceleration, stress, and pore water pressure is normal, so as to ensure the accuracy and completeness of the test data.

[0032] S15. Turn on the shaking table, input seismic waves according to the preset scheme, collect sensor data synchronously during the test, and record the seepage interface inside the transparent observation panel captured by the high-speed camera. Obtain the dynamic response and seepage evolution data of the model under different seismic loads, and provide direct basis for analyzing the impact of earthquakes on the water seal and stability of the oil depot.

[0033] S16. After loading a single set of seismic waves, turn off the shaking table and data acquisition equipment, adjust the height of the water level sensor to change the groundwater level, or adjust the opening of the water curtain pressure regulating valve to change the water curtain tunnel pressure. After the pore water pressure in similar materials stabilizes, turn on the shaking table and input seismic waves with different characteristics. Repeat steps S14-S15 to complete the test under multiple parameter combinations.

[0034] S17. After all tests are completed, analyze the collected sensor data and image data, and obtain the acceleration amplification coefficient, stress distribution, pore water pressure variation law and water seal state of the model under different parameters by data comparison, and determine the test results of the underground water-sealed oil depot under vibration load.

[0035] The preferred embodiment of the experimental method for testing the water-sealing performance and stability of an underground water-sealed oil depot under seismic load simulation using a shaking table is as follows: The height of the water level sensor can be adjusted to regulate the water level within the similar material; the opening of the water curtain pressure regulating valve can be adjusted to regulate the water pressure within the water curtain tunnel and water curtain orifice. Through these parameter adjustments, multiple different working conditions can be set during the shaking table test to obtain experimental data related to the dynamic response, seepage characteristics, and water seal state of the model under different parameter conditions, providing a basis for evaluating the water seal effect and optimizing parameters. Beneficial effects

[0036] This invention is a test apparatus and method specifically designed for shaking table testing of underground water-sealed oil depots, enabling coupled simulation of "vibration-seepage-stability," thus overcoming the technical limitations of existing underground water-sealed oil depot tests. Existing tests related to underground water-sealed oil depots mostly only study the seepage field, failing to investigate the actual response of the oil depot under seismic loads, and lack a "side + bottom" bidirectional permeable device, making it impossible to simulate real boundary conditions. This apparatus can simultaneously simulate the seepage field and stability while simulating seismic vibration, filling the gap in dedicated shaking table test equipment and methods in this field.

[0037] This invention innovatively designs a stable groundwater level control device and a water curtain system water pressure control device, ensuring the accuracy and reliability of experimental parameter regulation. The groundwater level control device controls the height of the water level sensor via a slide rail, and the controller receives sensor data in real time, automatically triggering the start and stop of the water level control pump to achieve automatic maintenance of the groundwater level. The water curtain system, through a pressure control component consisting of a water curtain booster pump and a water curtain pressure regulating valve, can precisely regulate the water injection pressure in the water curtain tunnel, ensuring that the water curtain water uniformly penetrates the similar materials. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the overall core structure of the experimental device; Figure 2 A schematic diagram showing the arrangement of similar materials, water curtain system, and oil storage caverns; Figure 3 This is a front view of the overall core structure of the experimental device; Figure 4 Schematic diagram of a transparent observation panel; Figure 5 This is a schematic diagram of a side permeable panel; Figure 6 This is a schematic diagram of the side water tank and the groundwater level control device (slide rail, water level sensor); Figure 7 This is a schematic diagram of an oil storage cavern. Figure 8 This is a schematic diagram of a water curtain system; Figure 9 Schematic diagram of water curtain pressure control device; Figure 10 This is a schematic diagram of a groundwater level control device. Figure 11 Schematic diagram of the oil injection system for the oil storage chamber; Figure 12 This is a schematic diagram of the oil extraction and drainage system of the oil storage cavern.

[0039] In the diagram: 1. Main steel frame of the model box; 2. Similar materials; 3. Transparent observation panel; 301. Oil inlet; 302. Oil outlet; 303. Drainage outlet; 304. Transparent cavern cover; 4. Permeable plate; 401. Side permeable plate; 4011. Permeable hole in the side permeable plate; 4012. Connecting hole in the side permeable plate; 402. Bottom permeable plate; 4021. Permeable hole in the bottom permeable plate; 4022. Support column of the bottom permeable plate; 5. Bottom connecting plate; 501. Bottom connecting hole; 6. Water tank; 601. Side water tank; 6011. Water baffle plate in the side water tank; 602. Bottom water tank; 7. Oil storage cavern; 701. Main body of the oil storage cavern; 702. Water collection tank; 703. Submersible pump; 7031. Oil outlet pipe; 704. Seepage drainage pipe; 7041. Flow rate 705. Oil inlet pipe; 7051. Oil supply pump; 7052. Oil storage tank; 8. Water curtain system; 801. Water curtain tunnel; 8011. Water curtain tunnel permeable hole; 8012. Water curtain tunnel inlet; 802. Water curtain hole; 803. Water curtain pressure control device; 8031. Water curtain supply pipe; 8032. Water curtain pressure regulating valve; 8033. Water curtain booster pump; 8034. Water curtain system storage tank; 9. Groundwater level control device; 901. Slide rail; 9011. Slider; 9012. Slide rail fixing bolt; 902. Water level sensor; 9021. Sensor data cable; 903. Controller; 904. Water level control pump; 905. Pressure stabilizing valve; 906. Water supply pipe; 9061. Water outlet tap; 907. Groundwater level storage tank. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention. Example

[0041] An experimental apparatus and method for testing the water-sealing performance and stability of an underground water-sealed oil depot under seismic loading using a shaking table. This embodiment provides an experimental apparatus and method for simulating the water-sealing performance and stability of an underground water-sealed oil depot under seismic loading using a shaking table. The aim is to simulate the dynamic response, seepage field evolution, and water-sealing effect of the surrounding rock of the underground water-sealed oil depot under seismic loading. The model chamber is specifically designed for shaking table testing and allows for manual control of the water level, water pressure in the water curtain system, and oil volume in the storage chamber, thus achieving controllable experimental parameters.

[0042] like Figures 1 to 12The core structural parameters of the experimental device of the present invention are as follows: The main steel frame of the model box is made of Q235 low carbon steel plate welded to form a rigid frame. The overall length, width and height are 180cm×100cm×120cm, the steel plate wall thickness is 10mm, and the corners are reinforced by welding 5mm thick triangular reinforcing plates to ensure that there is no deformation or loosening during vibration.

[0043] The transparent observation panel 3 is mounted on the inner side of the front steel plate of the main steel frame 1 of the model box. It is made of high-strength polycarbonate board (PC board) with a thickness of 15mm and a light transmittance of ≥85%. The panel size exceeds the rectangular opening of the front steel plate by 10cm on each side. It is fixed by bonding with special high-strength adhesive. The joints are first filled with shock-resistant sealant and then covered with butyl waterproof membrane. After standing for 24 hours, water is injected into the model box. If there is no leakage after 2 hours of observation, the sealing is qualified. A scale with an accuracy of 1mm is printed on the panel corresponding to the area of ​​the oil storage chamber 7 for real-time observation of oil level and seepage interface movement.

[0044] The side permeable plate 401 of the permeable plate 4 is made of 5mm thick stainless steel plate, and its size matches the side facade of the model box 100cm×120cm. The permeable plate is evenly distributed with permeable holes 4011 with a diameter of 5mm and a hole spacing of 10cm, in a plum blossom pattern. There are 10 side permeable plate connection holes 4012. The bottom permeable plate 402 is made of 5mm thick stainless steel plate, with a size of 150cm×100cm. The parameters of the permeable holes 4021 in the bottom permeable plate are the same as those in the side permeable plate. The bottom permeable plate support column 4022 is made of steel cylinder with a diameter of 50mm and a height of 10cm. Both ends are welded and fixed to the main steel frame 1 of the model box and the bottom permeable plate 402, respectively.

[0045] The side water tank 601 in the water tank 6 is formed by the side permeable plate 401 and the main steel frame 1 of the model box. The width of a single tank is 15cm, and there are two tanks on both sides. The side water tank baffle plate 6011 is made of 5mm thick transparent acrylic sheet, with a size of 100cm×15cm. It matches the top of the side water tank 601 and is fixed to the slider 9011 by bolts. The plate has small holes for the water tap 9061 and sensor data cable 9021 to pass through. The bottom water tank 602 is located between the bottom permeable plate 402 and the main steel frame 1 of the model box. It is 10cm high, the same height as the support column, and is connected to the side water tank 601 through the permeable hole 4011 of the side permeable plate.

[0046] The bottom connecting plate 5 is made of 10mm thick stainless steel plate, with dimensions of 220cm×140cm. The portion exceeding the size of the model box is used to accommodate the distribution of bolt holes on the vibration table surface. Bottom connecting holes 501 are evenly distributed on the plate, with a hole diameter of 16mm and a hole spacing of 20cm. It is rigidly connected to the vibration table surface by M14 high-strength bolts. Anti-slip grease is applied to the connecting surface to ensure no relative displacement during vibration.

[0047] The model box is filled with a similar material 2, whose physical and mechanical parameters meet the same conditions as the surrounding rock of the actual oil depot. A water curtain system 8 and an oil storage cavern 7 are arranged sequentially inside the similar material 2.

[0048] The cross-section of the oil storage cavern 7 is a straight-walled arch shape. After scaling down to a geometric scale, its dimensions are: span 10cm, height 15cm, and length 100cm. These dimensions are consistent with the width of the model box and are formed by layering similar materials using a pre-set mold. The mold is closed on the side near the steel frame and attached to the transparent observation panel 3 on the side near the panel. The transparent observation panel 3 has a 30cm × 20cm opening corresponding to the position of the oil storage cavern 7, and a removable transparent cavern cover 304 is installed on it. The cover has three interfaces: an oil inlet 301, an oil outlet 302, and a drain outlet 303.

[0049] The water curtain system 8 includes a water curtain tunnel 801, water curtain holes 802, and a water curtain pressure control device 803. The water curtain tunnel 801 is arranged perpendicular to the axis of the oil storage cavern 7, with a straight-walled circular arch cross-section. Its dimensions (scaled down) are 3.5cm × 3cm, and it is located 12.5cm above the arch top of the oil storage cavern 7. Formed by embedding a pre-set mold, the water curtain tunnel 801 has evenly distributed permeable holes 8011 on its wall, with a hole diameter of 2mm and a hole spacing of 1.5cm, wrapped with permeable geotextile. The water curtain pressure control device 803 is used to regulate the water injection pressure of the water curtain system.

[0050] The side water tank 601 is equipped with a groundwater level control device 9, which includes a slide rail 901, a water level sensor 902, a controller 903, etc., and is used to adjust the groundwater level in the model.

[0051] The shaking table test method based on the above model box includes the following steps: Similarity ratio determined: Dimensional analysis is used to ensure that the scaled-down model accurately reflects the mechanical behavior of the prototype structure. Density and length are selected as the fundamental dimensions, and following the law of gravitational similarity, the dimensional relationships of the main physical quantities in the model are derived: (1) Geometric scale Set geometric length similarity ratio ( For prototype size, (for model dimensions) (2) Density ratio Set density similarity ratio ( For the prototype rock mass density, (for similar material densities) (3) Acceleration ratio Set acceleration similarity ratio

[0052] (4) Time scale Time similarity ratio

[0053] (5) Velocity (flow rate) scale Speed ​​similarity ratio

[0054] (6) Stress and elastic modulus ratio Stress and elastic modulus similarity ratio

[0055] (7) Permeability coefficient scale The permeability coefficient similarity ratio is equal to the velocity similarity ratio. .

[0056] Configure similar materials: Based on the physical and mechanical parameters of the surrounding rock of the actual underground water-sealed oil depot, similar material 2 that meets the similar conditions was configured. The material ratio was determined through orthogonal experiments. Iron concentrate, quartz sand, white cement, gypsum and water were mixed in proportion, and standard specimens were made according to the ratio. After curing under standard conditions, the bulk density, uniaxial compressive strength, elastic modulus and permeability coefficient of the specimens were tested. The results were compared with the similarity ratio requirements. If the deviation exceeded 5%, the ratio was readjusted.

[0057] Assemble the model box: Clean the interior of the main steel frame 1 and the transparent observation panel 3 of the model box; Confirm that the permeable holes 4011 on the side permeable plate and 4021 on the bottom permeable plate are unobstructed. The side permeable plate 401 is positioned with the main steel frame 1 of the model box by bolts, and then reinforced by welding along the edge of the plate. The bottom permeable plate support column 4022 and the bottom permeable plate 402 are welded together. The main steel frame 1 of the model box is connected to the transparent observation panel 3 with special glue. The joint is coated with shock-resistant sealant, and then waterproof membrane is attached. Water is poured into the model box and left to stand. After checking for any leakage, the following operations are performed. Install slide rail 901 and calibrate its verticality; fix the side water tank baffle 6011 to slide rail 9011 with bolts, and test the vertical movement flexibility of the baffle. A 10cm thick polystyrene foam board is laid on the contact surfaces of the main steel frame 1, side permeable plate 401, bottom permeable plate 402, and similar material 2 of the model box to reduce the reflection effect of the rigid boundary on seismic waves. Model box connected to vibration table: The model box is connected to the vibration table surface using M14 high-strength bolts through the bottom connection hole 501 of the bottom connection plate 5.

[0058] Initial assembly and commissioning of the water curtain system: Connect the water curtain tunnel 801 to the water curtain hole 802 and the water curtain supply pipe 8031, and ensure that the interface is sealed. Add water to the water storage tank 8034 of the water curtain system, turn on the water curtain booster pump 8033, adjust the water curtain pressure regulating valve 8032 to 0.1MPa, check whether the water flow from the water curtain holes is uniform, and replace the thin tube of the water curtain hole if there is a blockage.

[0059] Laying similar materials and embedding internal components: Mark the installation locations of the water curtain system 8 and the oil storage chamber 7 inside the model box; Similar materials were laid in layers to the design height, and the main molds for the water curtain tunnel 801 and the oil storage chamber 7 were buried at the same time. According to the sensor layout diagram, an acceleration sensor, a stress sensor, and a pore water pressure sensor are arranged in similar material 2, and the sensor cables are connected to the data acquisition instrument. After each layer of similar material is laid, it is compacted with a loading plate. The layer-by-layer laying and compaction steps are repeated until the design height is reached.

[0060] Install and inspect the oil storage chamber components: Remove the transparent cavity cover plate 304 and slowly pull out the oil storage cavity mold using clamps; A water collection tank 702 is installed at the bottom of the oil storage cavern. A drain outlet 303 is connected to a seepage drain pipe 704 (with a flow meter 7041 and a filter screen installed at the drain outlet to prevent clogging). Water is injected into the oil storage cavern. After observing that the water outflow from the drain pipe is smooth and there is no leakage, the oil inlet pipe 705 (connecting the oil supply pump 7051 and the oil storage tank 7052) is connected to the oil inlet 301. The submersible pump 703 is connected to the oil outlet 302 through the oil outlet pipe 7031.

[0061] Install and commission the water curtain pressure control device and the groundwater level control device: Complete the final installation of the water curtain pressure control device 803 and the groundwater level control device 9, including connecting the water curtain pressure regulating valve 8032, the water level sensor 902, etc. Debugging the groundwater level control device: Set the initial water level, manually release water to 5cm below the set value, trigger the water level control pump to replenish water, and verify the water level recovery status. Debug the water curtain pressure control device: Set the pressure to 0.1 MPa, maintain the pressure for 30 minutes, and observe the values ​​of the pore water pressure sensor around the water curtain tunnel.

[0062] Setting up the initial experimental environment: Water is added to the side water tank 601, and the initial groundwater level is maintained by the groundwater level control device; the data of the pore water pressure sensor is monitored, and when the fluctuation of all sensor values ​​is ≤5%, it is determined that the similar material is completely saturated. Adjust the water curtain pressure to the design value, inject oil into the oil storage chamber 7 until the oil level reaches 70% of the chamber height, control the thickness of the water cushion layer at the bottom of the oil storage chamber 7, observe that there are no oil stains on the transparent panel and no water leakage in the water tank, and confirm that the initial state is qualified.

[0063] Deployment and calibration of monitoring equipment: A high-speed camera is placed on the outside of the transparent observation panel 3, and sensors and data acquisition equipment are calibrated.

[0064] Vibration test: Compress the seismic wave time and adjust the amplitude according to the similarity ratio, turn on the shaking table, input the seismic wave, and follow the loading sequence of frequency sweeping followed by loading. First, input 0.05g white noise for frequency sweeping, and then load according to the sequence of sine wave (0.1g to 0.2g) first and then natural wave (0.1g to 0.2g). Simultaneously collect sensor data and high-speed camera images.

[0065] Multi-condition testing: After loading a single set of seismic waves, the shaking table is turned off and the model is allowed to stand until the pore water pressure in the similar material stabilizes. The groundwater level or water curtain pressure is adjusted, and the test is repeated to complete the test under multiple parameter combinations (groundwater level, water curtain pressure, seismic wave type, amplitude).

[0066] Data Analysis: By analyzing sensor data and image data, we can obtain the acceleration amplification factor, stress distribution, pore water pressure variation law, and water seal status.

[0067] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating directions or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0068] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A test apparatus for the water-sealing performance and stability of an underground water-sealed oil depot under seismic load simulation using a shaking table, characterized in that, It includes a model box, similar materials (2), a water curtain system (8), an oil storage cavern (7), a water tank (6), and a groundwater level control device (9); The model box includes a main steel frame (1), a transparent observation panel (3), a permeable plate (4), and a bottom connecting plate (5); The main steel frame (1) of the model box is welded from five steel plates: left, right, front, back and bottom. A rectangular opening is provided in the middle of the front steel plate. The transparent observation panel (3) is attached to the inside of the front steel plate, and its size is larger than the rectangular opening. The joint is sealed. The permeable plate (4) includes a side permeable plate (401) and a bottom permeable plate (402); The side permeable plate (401) is provided with side permeable plate permeable holes (4011) and side permeable plate connecting holes (4012). The side permeable plate (401) is connected to the main steel frame (1) of the model box by bolts through the side permeable plate connecting holes (4012). Then, it is reinforced by welding along the inner contact edge of the main steel frame (1) of the model box. The bottom permeable plate (402) is provided with bottom permeable plate permeable holes (4021), and a bottom permeable plate support column (4022) is provided below it. The two ends of the bottom permeable plate support column (4022) are welded and fixed to the bottom permeable plate (402) and the main steel frame (1) of the model box, respectively. The bottom connecting plate (5) is located below the main steel frame (1) of the model box, and the bottom connecting plate (5) is provided with multiple bottom connecting holes (501); The water tank (6) includes a side water tank (601), a bottom water tank (602), and a side water tank baffle (6011); The side water trough (601) is formed by the side permeable plate (401) and the main steel frame (1) of the model box. The side water trough baffle plate (6011) is located on the top of the side water trough (601) and can move vertically. The bottom water tank (602) is located between the bottom permeable plate (402) and the main steel frame (1) of the model box, and is connected to the side water tank (601) through the permeable holes (4011) of the side permeable plate to form a complete groundwater boundary condition; The groundwater level control device (9) is installed inside the side water tank (601); The similar material (2) is laid in layers inside the model box, covering the inside of the side permeable plate (401) and the top of the bottom permeable plate (402). The water curtain system (8) and the oil storage cavern (7) are arranged in sequence inside the similar material (2). A scale is marked on the transparent observation panel (3) for observing the oil level and seepage in the oil storage cavern (7).

2. The test apparatus for the water-sealing performance and stability of an underground water-sealed oil depot under simulated seismic load using a shaking table, as described in claim 1, is characterized in that: The oil storage cavern (7) includes an oil storage cavern body (701), a water collection tank (702), a submersible pump (703), an oil outlet pipe (7031), a seepage drainage pipe (704), and an oil inlet pipe (705); The water collection tank (702) is located at the bottom of the oil storage cavern (7); the main body (701) of the oil storage cavern has a straight wall arched cross section, which is formed by laying similar materials (2) in layers using a pre-set mold. The main body (701) of the oil storage cavern is closed on one side near the main steel frame (1) of the model box, and the other side is attached to the transparent observation panel (3); The transparent observation panel (3) is provided with a detachable transparent cavern cover (304) opposite to the oil storage cavern (7). The transparent cavern cover (304) has an oil inlet (301), an oil outlet (302) and a drain outlet (303). The drain outlet (303) is connected to the water collection tank (702) through the seepage drain pipe (704), and a flow meter (7041) is installed on the seepage drain pipe; The submersible pump (703) is placed above the water collection tank (702), and the submersible pump (703) is connected to the oil outlet (302) through the oil outlet pipe (7031); The oil inlet (301) is located above the oil outlet (302), and the oil inlet (301) is connected to the main body (701) of the oil storage chamber through the oil inlet pipe (705); the oil inlet pipe (705) is connected to the oil supply pump (7051) and the oil storage tank (7052).

3. The test apparatus for the water-sealing performance and stability of an underground water-sealed oil depot under simulated seismic load using a shaking table, as described in claim 1, is characterized in that: The water curtain system (8) includes a water curtain tunnel (801), water curtain holes (802), and a water curtain pressure control device (803). The water curtain tunnel (801) is located directly above the oil storage cavern (7), and its axial direction is perpendicular to the axial direction of the oil storage cavern (7). The cross-section of the water curtain tunnel (801) is a straight-walled circular arch, which is formed by embedding a pre-set mold. Multiple water curtain tunnel permeable holes (8011) and water curtain tunnel inlets (8012) are arranged on the water curtain tunnel (801). The water curtain hole (802) is composed of porous PVC thin tubes and is located at the lowest water curtain tunnel permeable hole (8011) on the side plate of the water curtain tunnel (801). The water curtain pressure control device (803) includes a water curtain supply pipe (8031), a water curtain pressure regulating valve (8032), a water curtain booster pump (8033), and a water curtain system storage tank (8034). The water curtain supply pipe (8031) is connected to the water curtain tunnel (801) through the water curtain tunnel inlet (8012). The water curtain system storage tank (8034) is connected to the water curtain booster pump (8033) and the water curtain pressure regulating valve (8032) in sequence, and finally connected to the water curtain supply pipe (8031) to control the water injection pressure of the water curtain system (8).

4. The test apparatus for the water-sealing performance and stability of an underground water-sealed oil depot under simulated seismic load using a shaking table, as described in claim 1, is characterized in that: The groundwater level control device (9) includes a slide rail (901), a water level sensor (902), a controller (903), a water level control pump (904), a pressure stabilizing valve (905), a water supply pipe (906), and a groundwater level storage tank (907); The slide rail (901) is installed on the side of the main steel frame (1) of the model box inside the side water tank (601) by slide rail fixing bolts (9012), and a slider (9011) is installed on the slide rail; the water level sensor (902) is connected to the slide rail through the slider (9011); the side water tank baffle (6011) is installed on the upper part of the slider (9011) and above the water level sensor (902), and can move vertically along the slide rail (901) with the slider; the side water tank (601) is marked with water level lines inside; The controller (903) is connected to the water level sensor (902) via a sensor data line (9021); The water level control pump (904) has its inlet connected to the groundwater storage tank (907) and its outlet connected to the pressure stabilizing valve (905). One end of the water supply pipe (906) is connected to the pressure stabilizing valve, and the other end is connected to the water outlet faucet (9061). The water outlet faucet (9061) is placed inside the side water tank (601) through a small hole on the side water tank baffle plate (6011). The controller (903) is connected to the switch of the water level control pump (904).

5. A test method for the water-sealing performance and stability of an underground water-sealed oil depot under simulated seismic load using a shaking table, characterized in that... Using the test apparatus according to any one of claims 1-4, the steps include: S1, Assembly Model Box Clean the inside of the main steel frame (1) and the transparent observation panel (3) of the model box, and check the welding integrity of the main steel frame of the model box; Confirm that the permeable holes (4011) of the side permeable plate and the permeable holes (4021) of the bottom permeable plate are unobstructed. Connect the side permeable plate (401) to the main steel frame (1) of the model box through the connecting hole (4012) of the side permeable plate. Fix the bottom permeable plate support column (4022) and the bottom permeable plate (402). Weld and reinforce the contact points between the side permeable plate (401) and the bottom permeable plate (402) and the inner side of the main steel frame (1) of the model box. Install the side slide rails (901). The transparent observation panel (3) is attached to the inside of the front steel plate of the main steel frame (the size is slightly larger than the rectangular opening of the front steel plate), and the joint is filled with shock-resistant sealant and covered with waterproof membrane. The model box is bolted to the vibration table surface through the bottom connection hole (501) on the bottom connection plate (5); S2, Configure similar materials Based on the actual physical and mechanical parameters of the surrounding rock of the underground water-sealed oil depot, similar materials that meet the similar conditions are configured (2); S3. Assemble and inspect the water curtain system. Assemble the water curtain system (8), and check the unobstructedness of the water curtain tunnel permeable holes (8011) and water curtain holes (802) on the water curtain tunnel (801) and the status of the water curtain pressure control device (803); S4. Laying similar materials and arranging molds for oil storage caverns and water curtain systems: Mark the installation positions of the water curtain system (8) and the oil storage chamber (7) inside the main steel frame (1) of the model box, spread similar materials (2) in layers to the design height of the oil storage chamber (7), put in the main mold of the oil storage chamber and fix it; Continue to lay similar materials (2) in layers to the design height of the water curtain system (8), and connect the water curtain tunnel (801) with the water curtain hole (802) and the water curtain water supply pipe (8031), and arrange them in a direction perpendicular to the axis of the oil storage cavern (7); S5, Arrange sensors According to the sensor layout diagram, when similar material (2) is laid to the predetermined position, an acceleration sensor, a stress sensor and a pore water pressure sensor are arranged, and the sensor cables are led out from the top and connected to the data acquisition instrument. S6, similar materials to layered compaction After each layer of similar material (2) is laid, it is compacted with a loading plate. The layer-by-layer laying and compaction steps are repeated until the similar material (2) is filled to the design height. S7. Install relevant components for the oil storage chamber. Remove the transparent cavern cover plate (304) and pull out the main mold of the oil storage cavern; arrange a water collection tank (702) at the bottom of the oil storage cavern (7), connect the drain outlet (303) to the water collection tank (702) through the seepage drainage pipe (704), install a flow meter (7041) on the seepage drainage pipe (704), connect the oil inlet (301) to the main body of the oil storage cavern (701) through the oil inlet pipe (705), connect the oil inlet pipe (705) to the oil supply pump (7051) and the oil storage tank (7052), place the submersible pump (703) above the water collection tank (702) and connect it to the oil outlet (302) through the oil outlet pipe (7031), install the transparent cavern cover plate (304) onto the transparent observation panel (3) and seal it. S8. Complete the installation of the water curtain system. Connect the water curtain pressure regulating valve (8032), water curtain booster pump (8033) and water curtain system storage tank (8034) of the water curtain system (8) to the water curtain water supply pipe (8031) to complete the installation of the water curtain system (8); S9. Complete the installation of the groundwater level control device. The water level sensor (902) and the side water tank baffle (6011) are fixed on the slide rail (901) by the slider (9011) on the inner wall of the side water tank (601). The controller (903) is connected to the water level sensor (902) through the sensor data line (9021). The other end of the controller (903) is connected to the water level control pump (904) switch. The inlet of the water level control pump (904) is connected to the groundwater level storage tank (907), and the outlet is connected to the pressure stabilizing valve (905). One end of the water supply pipe (906) is connected to the pressure stabilizing valve, and the other end is connected to the water tap (9061). The water tap (9061) is placed inside the side water tank (601) through the small hole on the side water tank baffle (6011), thus completing the installation of the groundwater level control device (9). S10. Constructing the initial test environment Water is added to the side water tank (601), and the water flows into the bottom water tank (602) through the permeable holes (4011) of the side permeable plate. The initial groundwater level is adjusted by the water level control pump (904) and the water level sensor (902). After the similar material (2) is saturated with water, the opening of the water curtain pressure regulating valve (8032) is adjusted to set the initial water curtain tunnel (801) pressure. Oil is injected into the main body of the oil storage cavern (701) through the oil inlet (301) and the oil inlet pipe (705). The thickness of the water cushion layer at the bottom of the main body of the oil storage cavern (701) is controlled by the drain outlet (303) to ensure that there is no oil leakage. S11. Deploy monitoring equipment A high-speed camera is placed on the outside of the transparent observation panel (3). The lens angle of the high-speed camera is adjusted so that the lens is perpendicular to the transparent observation panel (3) to ensure that the seepage interface can be clearly captured. S12, Sensor and Data Acquisition System Calibration Turn on the high-speed camera and calibrate the sensor data acquisition accuracy to ensure that acceleration, stress, and pore water pressure data are acquired normally. S13, Seismic Wave Loading and Data Acquisition Turn on the shaking table, input seismic waves according to the preset scheme, and simultaneously collect sensor data and high-speed camera records the seepage interface trajectory inside the transparent observation panel (3) during the test. S14. Repeated operation of multi-condition test After a single set of seismic waves is loaded, the vibration table and data acquisition equipment are turned off. The height of the water level sensor (902) is adjusted to change the groundwater level, or the opening of the water curtain pressure regulating valve (8032) is adjusted to change the pressure of the water curtain tunnel (801). After the pore water pressure in the similar material (2) stabilizes, the vibration table is turned on and seismic waves with different characteristics are re-inputted to complete the test under multiple sets of "groundwater level-water curtain pressure-seismic wave" parameter combinations. S15. Experimental Data Processing and Result Analysis After all the experiments were completed, the collected sensor data and image data were analyzed. By comparing the data, the acceleration amplification factor, stress distribution, pore water pressure variation law and water seal state of the model under different parameters were obtained, and the experimental results were determined.

6. The test method for the water-sealing performance and stability of an underground water-sealed oil depot under simulated seismic load using a shaking table, as described in claim 5, is characterized in that: The water level in the similar material (2) can be changed by adjusting the height of the water level sensor (902), and the water pressure in the water curtain tunnel (801) and water curtain hole (802) can be changed by adjusting the valve opening of the water curtain pressure regulating valve (8032). During the vibration table test, multiple different working conditions can be set to obtain test data related to the dynamic response, seepage characteristics and water seal status of the model under different parameter conditions.

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