A similar simulation test device and method for underground water-gas interaction in karst depression reservoir construction

Abstract

The present invention discloses a similar simulation test device and method for underground water-gas interaction in karst depression reservoir construction, characterized by comprising a box (1), a karst pipeline structure simulation module provided in the box (1), a surface structure simulation module provided on the karst pipeline structure simulation module, and a water level evolution and rainfall working condition simulation module and a water-gas-force-deformation monitoring module provided in the box (1). The present invention can simulate and monitor the mechanical response of various complex working conditions of karst reservoir construction projects, such as underground water-gas pressure, infiltration process, and surface deformation, during the process of groundwater level rise and fall. The present invention can provide strong support for feasibility analysis and safety evaluation of karst depression reservoir construction.

Description

Technical Field

[0001] The invention relates to a similar simulation test device and method for underground water-gas interaction in a karst depression reservoir construction, belonging to the technical field of indoor similar simulation tests for karst depression reservoir construction in water conservancy projects. Background Art

[0002] Karst depressions are products of the early and middle stages of karst landform development. Typical karst depressions are nearly circular, enclosed landforms resembling the bottom of a pot. Utilizing the natural negative topography of karst depressions, reservoir construction requires minimal excavation and backfilling, making them ideal locations for pumped hydropower storage and the storage of ash and waste residues. These areas are in great demand in the energy and mining sectors.

[0003] The construction of pumped-storage reservoirs in karst depressions is essential for achieving the integrated development of wind, solar, hydro, thermal, and energy storage. The development of traditional energy industries, particularly new energy sources (such as wind and solar), has created a significant demand for pumped-storage reservoirs with regulation and storage capabilities. Utilizing karst depressions to construct pumped-storage power stations provides an effective solution for further tapping the potential of hydropower generation and regulating and storing new energy. Furthermore, reservoirs in karst depressions are a key approach to addressing environmental pollution from mining development. With the large-scale mining and utilization of mineral resources, large quantities of general industrial solid waste (ash, tailings, and waste residue) have been and will continue to be generated, placing a greater demand on land resources for slag storage in karst areas.

[0004] Currently, there are few engineering practices for the development and utilization of karst depressions, and there is a lack of theoretical and technical methods for karst depression reservoir construction. The key to utilizing karst depressions for pumped-storage reservoirs and industrial solid waste storage facilities is ensuring the reliability of anti-seepage engineering and the stability of the reservoir itself. However, karst depressions often harbor karst channels such as sinkholes, funnels, and dissolution fissures. To prevent leakage, large-scale karst channels in karst depression reservoirs and slag storage facilities must be sealed and fully covered with anti-seepage measures. However, the sealing of sinkholes, funnels, and other structures in depressions, which serve as primary channels for groundwater and gas discharge, will significantly alter the groundwater and gas environment. Fluctuations in the groundwater level will generate significant water-gas pressure effects (vacuum erosion, positive pressure jacking, etc.), significantly impacting the stability and anti-seepage performance of the project. Conducting systematic research on the water-gas interaction mechanisms in karst depression reservoir construction, developing disaster control technologies for depression reservoir construction, and developing comprehensive theoretical and technical methods for karst depression reservoir construction have important scientific value and engineering application prospects.

[0005] Chinese patent CN110954352A - An energy underground structure model experimental testing system, comprising: a model unit, the model unit comprising a model box containing test soil and an energy underground structure model set in the test soil; a temperature loading unit comprising a water tank, a water pump, a temperature circulation controller and a heat exchange tube connected in sequence by pipes, the heat exchange tube being built into the energy underground structure model; an air loading unit comprising an air fluid for applying different temperatures and / or velocities to the energy underground structure model; a detection unit comprising a temperature sensor array arranged in the test soil, a temperature sensor and a strain sensor arranged in the energy underground structure model, the temperature sensor and the strain sensor being respectively connected to a demodulator, and the demodulator being connected to a computer. This patented technology is targeted at energy underground structures and cannot simulate the various address conditions and working conditions studied in karst depressions. Summary of the Invention

[0006] The present invention aims to provide a similar simulation test device and method for groundwater-gas interactions in karst depression reservoirs. This device simulates groundwater-gas interactions (vacuum erosion and positive pressure jacking) caused by various geological conditions and operating conditions (such as groundwater level fluctuations and loading and unloading within the reservoir). This provides support for studying the reliability of anti-seepage and reservoir stability under various operating conditions.

[0007] The technical solution of the present invention is: a similar simulation test device for underground water and gas interaction in a karst depression reservoir, comprising a box body, a karst pipeline structure simulation module is provided in the box body, a surface structure simulation module is provided on the karst pipeline structure simulation module, and a water level evolution and rainfall condition simulation module and a water-gas-force-deformation monitoring module are also provided in the box body.

[0008] The above-mentioned karst depression reservoir construction underground water-gas interaction similarity simulation test device, the karst pipeline structure simulation module includes a formation simulation module, and an underground karst pipeline system is arranged in the formation simulation module, and the underground karst pipeline system is connected to the lateral supply pipeline and the karst underground river channel.

[0009] The above-mentioned karst depression reservoir construction underground water-gas interaction similarity simulation test device, the surface structure simulation module includes a reservoir module, the reservoir module is provided with an anti-seepage membrane and a cushion layer, and the cushion layer is provided with a surface rock structure.

[0010] The above-mentioned karst depression reservoir construction underground water-gas interaction similarity simulation test device, the water level evolution and rainfall condition simulation module includes a rainfall simulation device, a water supply tank, the water supply tank is connected to the water supply pipe, the water supply pipe is provided with a water supply pipe valve, the water supply pipe is connected to the inlet and outlet pipes, the inlet and outlet pipes are respectively provided with an inlet pipe valve and an outlet pipe valve, and the inlet and outlet pipes are also connected to a high-pressure pump.

[0011] The above-mentioned karst depression reservoir construction underground water-gas similar simulation test device, the water-gas-force-deformation monitoring module includes a water vapor pressure sensor, an ultrasonic water level monitor, a membrane deformation meter, a water level monitor, a flow meter, a water content sensor and a three-dimensional laser scanner. The water vapor pressure sensor and the ultrasonic water level monitor are arranged in the surface structure simulation module, the membrane deformation meter is arranged on the anti-seepage membrane, the water level monitor is arranged on the reservoir module, the flow meter is arranged on the karst underground river channel, the water content sensor is arranged in the formation simulation module, and the three-dimensional laser scanner is arranged in the upper part of the box.

[0012] The test method of the groundwater-gas interaction simulation test device for building a reservoir in a karst depression is to set up a karst pipeline structure simulation module in the box by selecting materials and structural shapes according to actual engineering measurements or test requirements;

[0013] Design the surface simulation structure and set up the surface structure simulation module according to the landform characteristics and engineering measures;

[0014] Set up water level evolution and rainfall condition simulation modules in the surface structure simulation module, and connect them to the water-air-force-deformation monitoring module;

[0015] The water level evolution and rainfall condition simulation module is used to control the pumping and drainage rates within the surface structure simulation module and the box, and the pumping and drainage flow rates are recorded in real time. The evolution of various physical quantities in the geotechnical materials is monitored through the water-air-force-deformation monitoring module to complete the test.

[0016] The beneficial effects of this invention are as follows: Through the combination of various modules, the test device can simulate groundwater vapor interactions (vacuum erosion and positive pressure jacking) caused by various geological conditions (stratum permeability coefficient, karst channel morphology) and various operating conditions (groundwater level fluctuation, reservoir loading and unloading, and heavy rain). The simulated stratum material permeability and underground karst space morphology are determined based on similarity criteria. The stratum material and karst space serve as interchangeable modules, enabling simulation of complex geological conditions. By utilizing a water supply tank, high-pressure pump, and valve system, in conjunction with a monitoring module, the device can simulate and monitor the mechanical responses of various complex karst reservoir construction projects, including groundwater vapor pressure, permeability processes, and surface deformation during groundwater level fluctuations. This provides strong support for feasibility analysis and safety assessment of reservoir construction in karst depressions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Reference numerals: 1—box;

[0019] The water level evolution and rainfall condition simulation module includes: 11—rainfall simulation device; 12—water supply tank; 13—water supply pipe; 141—water supply pipe valve; 142—water inlet pipe valve; 143—water outlet pipe valve; 144—lateral supply pipe valve; 15—water inlet and outlet pipes; 16—high-pressure pump;

[0020] Water-air-force-deformation monitoring module, including: 21 - water-air pressure sensor; 22 - ultrasonic water level monitor; 23 - membrane deformation meter; 24 - water level monitor; 25 - flow meter; 26 - moisture content sensor; 27 - 3D laser scanner;

[0021] The surface structure simulation module includes: 31—reservoir contents (reservoir water or slag); 32—impermeable membrane; 33—cushion; 34—surface rock structure;

[0022] The karst pipeline structure simulation module includes: 41—stratum simulation materials; 42—underground karst pipeline system; 43—lateral supply pipeline; 44—karst underground river channel. DETAILED DESCRIPTION

[0023] To further illustrate the technical means and effectiveness of the present invention in achieving its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail the specific implementation, structure, features, and effectiveness of the groundwater-gas interaction simulation test device for reservoir construction in karst depressions proposed by the present invention. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0024] The term "and / or" in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B, specifically understood as: A and B may be included at the same time, A may exist alone, or B may exist alone, and any of the above three situations may exist.

[0025] An embodiment of the present invention: A similar simulation test device for underground water-gas interaction in a karst depression reservoir construction, comprising a box 1, a karst pipeline structure simulation module provided in the box 1, a surface structure simulation module provided on the karst pipeline structure simulation module, a water level evolution and rainfall condition simulation module and a water-gas-force-deformation monitoring module also provided in the box 1.

[0026] The karst pipeline structure simulation module includes a formation simulation module 41, within which is located an underground karst pipeline system 42, which connects to a lateral supply pipeline 43 and a karst underground river channel 44. The formation simulation module 41 is constructed of similar materials with different permeabilities and mechanical properties, as determined according to similarity criteria; the underground karst pipeline system 42 is a cylindrical, variable-diameter model, or a measured generalized model.

[0027] The surface structure simulation module includes a reservoir contents module 31, which is equipped with an impermeable membrane 32 and a cushion layer 33. The cushion layer 33 is a surface rock structure 34. Depending on the simulation scenario, the surface rock structure 34 can include fractured rock structures, cylindrical sinkholes, collapse-extension structures, or mixed depression-karst structures. Reservoir contents 31 can be composed of reservoir water and slag pile 2, simulating two types of projects, respectively. The materials and geometries of the impermeable membrane 32 and cushion layer 33 are determined based on similarity criteria based on actual projects.

[0028] The water level evolution and rainfall condition simulation module includes a rainfall simulation device 11 and a water supply tank 12. The water supply tank 12 is connected to a water supply pipe 13, which is equipped with a water supply valve 141. The water supply pipe 13 is connected to an inlet and outlet pipe 15, each equipped with an inlet valve 142 and an outlet valve 143. The inlet and outlet pipes 15 are also connected to a high-pressure pump 16. The water level evolution and rainfall condition simulation module is a system for controlling the simulated conditions. The water supply tank 12, high-pressure pump 16, and outlet pipe 15, in conjunction with a valve system, implement the water vapor pressure loading during the test. The rainfall simulation device 11 is used to change the moisture content of the simulated material and the amount of water in the hole to simulate rainfall conditions.

[0029] The water-gas-force-deformation monitoring module includes a water vapor pressure sensor 21, an ultrasonic water level monitor 22, a membrane deformation meter 23, a water level monitor 24, a flow meter 25, a moisture sensor 26 and a three-dimensional laser scanner 27. The water vapor pressure sensor 21 and the ultrasonic water level monitor 22 are arranged in the surface structure simulation module, the membrane deformation meter 23 is arranged on the anti-seepage membrane 32, the water level monitor 24 is arranged on the reservoir module 31, the flow meter 25 is arranged on the karst underground river channel 44, the moisture sensor 26 is arranged in the formation simulation module 41, and the three-dimensional laser scanner 27 is arranged in the upper part of the box 1. The water-vapor-force-deformation monitoring module is a test module for the experimental process. A water-vapor pressure sensor 21 monitors the water-vapor pressure within the karst piping system 42, the lateral supply channel 43, and the formation simulation material 41. An ultrasonic water level monitor monitors the water level within the karst piping system 42. The membrane deformation monitor monitors the deformation of the anti-seepage membrane during the test. A flow meter 25, installed on the inlet and outlet pipes 15, monitors the water inflow and outflow. A water content sensor 26 monitors the water content within the formation simulation material 41.

[0030] The test method of the groundwater-gas interaction simulation test device for building a reservoir in a karst depression is to set up a karst pipeline structure simulation module in the box by selecting materials and structural shapes according to actual engineering measurements or test requirements;

[0031] Design the surface simulation structure and set up the surface structure simulation module according to the landform characteristics and engineering measures;

[0032] Set up water level evolution and rainfall condition simulation modules in the surface structure simulation module, and connect them to the water-air-force-deformation monitoring module;

[0033] The water level evolution and rainfall condition simulation module is used to control the pumping and drainage rates within the surface structure simulation module and the box, and the pumping and drainage flow rates are recorded in real time. The evolution of various physical quantities in the geotechnical materials is monitored through the water-air-force-deformation monitoring module to complete the test.

[0034] The technical solution of the present invention is further described below through specific embodiments:

[0035] Example 1: Simulation of positive pressure support effect of karst depression reservoir

[0036] The positive pressure jacking effect caused by the rise of groundwater level and the negative pressure erosion effect caused by the drop of groundwater level are important contents of the feasibility study of reservoir construction in karst depressions.

[0037] According to the engineering geological parameters and engineering operation conditions, the formation simulation materials 41 are configured according to the similarity criteria to meet the similarity of mechanical parameters and permeability; an underground karst pipeline system 42, a lateral recharge system and a karst underground river pipeline are constructed;

[0038] According to engineering geological parameters and similarity criteria, the surface rock structure 34, cushion layer 33 and anti-seepage membrane 32 are laid; the slag or water in the reservoir is designed according to the actual project;

[0039] Design the groundwater rise rate based on actual engineering measurements or statistical parameters and convert it into injection flow; open all monitoring modules.

[0040] To address the positive pressure jacking condition caused by the rising groundwater level, fill the water supply tank 12 with water, close the outlet valve 143, open the water supply pipe valve 141, keep the lateral supply pipe valve 144 closed, adjust the water inlet pipe valve 142, observe the flow meter 25, and inject water at the designed flow rate. The water level in the underground karst pipe system 42 gradually rises;

[0041] During the experiment, water vapor pressure sensors 21 in the karst piping system 42 and the formation simulating material 41 monitored changes in water vapor pressure in the system in real time. An ultrasonic water level monitor 22 monitored water vapor pressure in the karst piping system 42 in real time. A membrane deformation meter 23 monitored deformation of the anti-seepage membrane in real time. A moisture content sensor 26 monitored changes in moisture content within the formation simulating material in real time. A 3D laser scanner 27 monitored displacement within the reservoir in real time. This monitoring system provides information on water vapor pressure within the karst cavity and the evolution of the groundwater level throughout the entire process of groundwater level rise, as well as water vapor pressure and water vapor penetration within the rock mass, and deformation of the cushion layer, anti-seepage membrane, and reservoir interior.

[0042] After the water level in the karst pipeline system during the test reaches the design height or the test requirement, all test systems are closed, the water supply pipe valve 141 is closed, and to prevent the impact of the groundwater drop on the cushion layer and the anti-seepage membrane, the lateral supply pipeline valve 144 is opened, and the outlet pipe valve 143 is opened. The water in the test system is discharged through the inlet and outlet pipes, and the positive pressure erosion test is completed.

[0043] If you need to simulate a very high positive pressure, the water supply device needs to be changed from the water supply tank 12 to the high-pressure pump 16. Before pressurization, close the water supply pipe valve 141 and the outlet pipe valve 143, open the high-pressure pump 16 to supply water, and open the water inlet pipe valve 142 to provide higher water pressure from the high-pressure pump 16.

[0044] Since the equipment is modular, by changing the surface structure simulation module and the karst pipeline simulation module in the same way, the water-air-force-deformation evolution process of the karst depression reservoir under different geological conditions and different groundwater level drop rates can be studied.

[0045] Example 2: Simulation of negative pressure erosion effect in karst depression reservoir

[0046] According to the engineering geological parameters and engineering operation conditions, the formation simulation materials 41 are configured according to the similarity criteria to meet the similarity of mechanical parameters and permeability; an underground karst pipeline system 42, a lateral recharge system and a karst underground river pipeline are constructed;

[0047] According to engineering geological parameters and similarity criteria, the surface rock structure 34, cushion layer 33 and anti-seepage membrane 32 are laid; the slag or water in the reservoir is designed according to the actual project;

[0048] Design the water level drop rate based on actual project measurements or statistical parameters and convert it into drainage flow; open all monitoring modules.

[0049] To address the negative pressure erosion caused by the drop in groundwater level, first fill the water supply tank 12 with water, close the outlet valve 143, open the lateral supply pipe valve 144, open the water supply pipe valve 141, open the water inlet pipe valve 142, and observe the ultrasonic water level monitor 22. When the water level in the karst pipe system 42 reaches the design value, close the water inlet pipe valve 142, close the water supply pipe valve 141, and open the water outlet pipe valve 143.

[0050] The water inlet valve 142 is adjusted in conjunction with the flow meter 25 to make the drainage flow reach the designed value.

[0051] During the test, water vapor pressure sensors 21 in the karst piping system 42 and the formation simulating material 41 monitored changes in water vapor pressure in the system in real time. An ultrasonic water level monitor 22 monitored water vapor pressure in the karst piping system 42 in real time. A membrane deformation meter 23 monitored deformation of the anti-seepage membrane in real time. A moisture content sensor 26 monitored changes in moisture content within the formation simulating material in real time. A 3D laser scanner 27 monitored displacement within the reservoir in real time. This monitoring system captured the evolution of water vapor pressure within the karst cavity, the groundwater level, water vapor pressure within the rock mass, and deformation of the cushion layer, anti-seepage membrane, and reservoir interior during the entire process of water level drop within the karst piping system.

[0052] Since the equipment is modular, by changing the surface structure simulation module and the karst pipeline simulation module in the same way, the water-air-force-deformation evolution process of the karst depression reservoir under different geological conditions and different groundwater level rise rates can be studied.

[0053] Example 3: Simulation test of groundwater pressure in karst depression reservoir under rainfall conditions

[0054] Studying the evolution characteristics of water and gas pressure in karst depression reservoirs under rainfall conditions provides support for actual karst depression reservoir construction projects.

[0055] According to the geological conditions of the actual project, the formation simulation material 41 is configured according to the similarity principle to meet the similarity of mechanical parameters and permeability; an underground karst pipeline system 42, a lateral supply system and a karst underground river pipeline are constructed;

[0056] According to engineering geological parameters and similarity criteria, the surface rock structure 34, cushion layer 33 and anti-seepage membrane 32 are laid; the slag or water in the reservoir is designed according to the actual project;

[0057] Calculate simulated rainfall according to rainfall conditions;

[0058] Close the water outlet valve 143, close the water supply pipe valve 141, close the water inlet valve 142, and open the lateral supply pipe valve 144;

[0059] All monitoring systems are turned on, the rainfall simulation device 11 is turned on, and the simulated rainfall is adjusted according to the designed rainfall.

[0060] During the experiment, a water level monitor monitored the reservoir water level in real time; water vapor pressure sensors 21 in the karst piping system 42 and the formation simulating material 41 monitored changes in water vapor pressure in the system; an ultrasonic water level monitor 22 monitored the water vapor pressure in the karst piping system 42; a membrane deformation meter 23 monitored the deformation of the anti-seepage membrane; a moisture content sensor 26 monitored changes in the moisture content of the formation simulating material; and a 3D laser scanner 27 monitored displacement within the reservoir. This monitoring system captured the evolution of water vapor pressure within the karst cavity, the groundwater level, the water vapor pressure in the rock mass, and the deformation of the cushion layer, anti-seepage membrane, and reservoir interior throughout the entire process of water level drop within the karst piping system.

[0061] When the groundwater level rises to the designed level and the test termination conditions are met, the rainfall simulator 11 is shut down, along with the entire monitoring system. The inlet and outlet valves 142 and 143 are opened to drain the underground karst pipe system 42 and the reservoir. The test is then terminated.

Claims

1. A similar simulation test device for underground water-gas interaction in karst depression reservoir construction, characterized by: The invention comprises a box (1), wherein a karst pipeline structure simulation module is provided in the box (1), a surface structure simulation module is provided on the karst pipeline structure simulation module, and a water level evolution and rainfall condition simulation module and a water-air-force-deformation monitoring module are also provided in the box (1); The karst pipeline structure simulation module includes a formation simulation module (41), an underground karst pipeline system (42) is provided in the formation simulation module (41), and the underground karst pipeline system (42) is connected to a lateral supply pipeline (43) and a karst underground river channel (44); The surface structure simulation module includes a reservoir content module (31), wherein the reservoir content module (31) is provided with an anti-seepage membrane (32) and a cushion layer (33), and the cushion layer (33) is provided with a surface rock structure (34). The water level evolution and rainfall condition simulation module comprises a rainfall simulation device (11), a water supply tank (12), the water supply tank (12) being connected to a water supply pipe (13), the water supply pipe (13) being provided with a water supply pipe valve (141), the water supply pipe (13) being connected to an inlet and outlet pipe (15), the inlet and outlet pipes (15) being provided with an inlet pipe valve (142) and an outlet pipe valve (143), respectively, and the inlet and outlet pipes (15) being further connected to a high-pressure pump (16); The water-gas-force-deformation monitoring module comprises a water-gas pressure sensor (21), an ultrasonic water level monitor (22), a membrane deformation meter (23), a water level monitor (24), a flow meter (25), a water content sensor (26) and a three-dimensional laser scanner (27), wherein the water-gas pressure sensor (21) and the ultrasonic water level monitor (22) are arranged in the surface structure simulation module, the membrane deformation meter (23) is arranged on the anti-seepage membrane (32), the water level monitor (24) is arranged on the reservoir module (31), the flow meter (25) is arranged on the karst underground river channel (44), the water content sensor (26) is arranged in the formation simulation module (41), and the three-dimensional laser scanner (27) is arranged in the upper part of the box (1); The test method of the groundwater-gas interaction similarity simulation test device for building a reservoir in a karst depression is to set a karst pipeline structure simulation module in a box by selecting materials and structural shapes according to actual engineering measurements or test requirements; Design the surface simulation structure and set up the surface structure simulation module according to the landform characteristics and engineering measures; Set up water level evolution and rainfall condition simulation modules in the surface structure simulation module, and connect them to the water-air-force-deformation monitoring module; The water level evolution and rainfall condition simulation module is used to control the pumping and drainage rates within the surface structure simulation module and the box, and the pumping and drainage flow rates are recorded in real time. The evolution of various physical quantities in the geotechnical materials is monitored through the water-air-force-deformation monitoring module to complete the test.

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