Fluid-solid coupling rock mechanics test device for simulating stability of borehole wall constructed by freezing method

Abstract

The invention discloses a fluid-solid coupling rock mechanics test device for simulating freezing method construction borehole wall stability, which comprises an experiment box body, a freezing pipe is vertically arranged in the middle in the experiment box body, the interior of the freezing pipe is used as a construction area, and a geotechnical material is filled in an area outside the freezing pipe in the experiment box body to serve as a water-bearing layer. The top of the freezing pipe is connected with the refrigerating system, one side of the experiment box is provided with the tide simulation device, the water supply system is connected with the experiment box and the tide simulation device, and the monitoring system is connected with the experiment box. The device can simulate the tide seepage state and monitor the stability of the well wall in real time, can provide more accurate mechanical parameters for freezing method construction on the basis of the fluid-solid coupling rock mechanics principle, and improves the reliability and efficiency of engineering design.

Description

Technical Field

[0001] This invention relates to a fluid-structure interaction rock mechanics test device for simulating the stability of well walls constructed by the freezing method. Background Technology

[0002] To mine mineral resources, many mine shafts are typically dug. When constructing these mine shafts, due to the low bearing capacity around them, it is necessary to freeze the area around the mine shafts before construction. With the scarcity of mineral resources and the discovery of underground minerals near the coast, near-shore mine construction has become a trend. However, near-shore freezing pipe construction is more complex due to the influence of tides and seepage. Therefore, near-shore freezing pipe simulation devices have become particularly important.

[0003] Existing freezing method construction test equipment mostly focuses on single-effect testing of freezing, lacking an integrated experimental platform that can simultaneously simulate underground tidal seepage, multi-field loading environments, and freezing mechanical response processes. Especially in near-shore and groundwater-rich areas, the stability of the strata around the freezing pipe is poor due to the influence of periodic water flow erosion and temperature changes, and traditional equipment cannot effectively reproduce actual working conditions. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a test system that integrates tidal simulation, cooling control, real-time monitoring, and ground pressure loading, and a reliable fluid-structure interaction rock mechanics test device for simulating wellbore stability during the freezing method.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is: a fluid-structure interaction rock mechanics test device for simulating the stability of well walls during freezing construction, comprising an experimental chamber, a freezing pipe vertically arranged in the middle of the experimental chamber, the area enclosed by the freezing pipe serving as the construction zone, the area inside the experimental chamber located outside the freezing pipe being filled with soil and rock material as an aquifer, a refrigeration system connected to the top of the freezing pipe, a tidal simulation device set on one side of the experimental chamber, a water supply system connected to the experimental chamber and the tidal simulation device respectively, and a monitoring system set around the freezing pipe.

[0006] The above-mentioned fluid-structure interaction rock mechanics test device for simulating well wall stability during freezing construction includes a monitoring system comprising a computer, a data processor, and sensors. Several sensors are installed around the freezing pipe, with the output of the sensors connected to the input of the data processor, and the output of the data processor connected to the computer.

[0007] The fluid-structure interaction rock mechanics test device for simulating well wall stability during the above-mentioned freezing method includes a temperature sensor, a humidity sensor, and a pressure sensor. The signal output terminals of the temperature sensor, humidity sensor, and pressure sensor are connected to the input terminal of the data processor via signal lines.

[0008] The above-mentioned fluid-structure interaction rock mechanics test device for simulating well wall stability during the freezing method includes a water supply system comprising a water tank, a water supply pump, and a first control valve. The tidal simulation device is connected to the water tank via the first control valve and the water supply pump. The water tank is connected to the flow field control system inside the test chamber via a water pipe. The flow field control system includes several capillary tubes installed in the aquifer, and a second control valve is installed on the water pipe.

[0009] The fluid-structure interaction rock mechanics test device for simulating well wall stability during freezing construction described above has a camera device fixedly installed at the bottom of the freezing pipe to observe the stress and rupture of the freezing pipe in real time and provide high-definition image feedback.

[0010] The above-mentioned fluid-structure interaction rock mechanics test device for simulating well wall stability during freezing construction includes a refrigeration system comprising a refrigeration unit and refrigeration pipes, with the refrigeration unit connected to the top of the freezing pipe via the refrigeration pipes.

[0011] The above-mentioned fluid-structure interaction rock mechanics test device for simulating the stability of well walls constructed by the freezing method has a filter screen plate installed around the inside of the test chamber. The filter screen plate has a filter screen in the middle. The filter screen has an adjustable structure, and the aperture and resistance can be adjusted according to different experimental requirements to control the uniformity of humidity distribution.

[0012] The above-mentioned fluid-structure interaction rock mechanics test device for simulating the stability of well walls constructed by the freezing method has a filter plate that can move axially to achieve horizontal loading around the freezing pipe. The top of the test chamber is equipped with a pressure loading plate, which can continuously apply vertical loads downward to the freezing pipe area to simulate the ground pressure environment.

[0013] The above-mentioned fluid-structure interaction rock mechanics test device for simulating the stability of well walls constructed by the freezing method includes a tidal simulation device comprising a tidal simulation box, a motor, and fan blades. The tidal simulation box is located close to the test chamber, and a motor is installed inside the tidal simulation box. A fan blade is installed on the output shaft of the motor, and the motor drives the fan blades to simulate the changes of tides.

[0014] The fluid-structure interaction rock mechanics test device described above for simulating well wall stability during freezing construction has an adjustable motor speed. By controlling the rotation speed of the fan blades, it can simulate tidal changes of different intensities and frequencies.

[0015] The beneficial effects of this invention are as follows:

[0016] 1. This invention can simulate tidal seepage and monitor wellbore stability in real time. Based on the principle of fluid-structure interaction rock mechanics, it can provide more accurate mechanical parameters for freezing method construction, thereby improving the reliability and efficiency of engineering design.

[0017] 2. This invention can adjust the appropriate humidity, pressure, etc. according to different underground environments during construction, making it more widely applicable and able to more realistically reflect the temperature and other environmental conditions of near-shore underground freezing pipes, providing experimental simulation equipment for the construction of near-shore underground freezing pipes. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the experimental chamber. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] like Figure 1 As shown, a fluid-structure interaction rock mechanics test device for simulating well wall stability during freezing construction includes an experimental chamber 1. A freezing pipe 2 is vertically installed in the middle of the experimental chamber 1. The area enclosed by the freezing pipe 2 serves as the construction zone 3. The area inside the experimental chamber 1 outside the freezing pipe 2 is filled with soil and rock material as an aquifer 4. A refrigeration system is connected to the top of the freezing pipe 2. A tidal simulation device 5 is installed on one side of the experimental chamber 1. A water supply system is connected to the experimental chamber 1 and the tidal simulation device 5 respectively. A monitoring system is installed around the freezing pipe 2.

[0022] The monitoring system includes a computer 6, a data processor 7, and sensors 8. Several sensors 8 are installed around the freezing tube 2. The output end of the sensor 8 is connected to the input end of the data processor 7, and the output end of the data processor 7 is connected to the computer 6.

[0023] The sensor 8 includes a temperature sensor, a humidity sensor, and a pressure sensor. The signal output terminals of the temperature sensor, humidity sensor, and pressure sensor are connected to the input terminal of the data processor 7 via signal lines 9.

[0024] The water supply system includes a water tank 10, a water pump 11, and a first control valve. The tidal simulation device 5 is connected to the water tank 10 via the first control valve and the water pump 11. The water tank 10 is connected to the flow field control system inside the experimental chamber 1 via a water pipe. The flow field control system includes several capillary tubes 12 installed in the aquifer 4, and a second control valve 13 is installed on the water pipe. The flow field control system supplies water to the experimental chamber 1 to maintain a realistic underground environment around the frozen pipe 2, disperses multiple capillary tubes 12 into the aquifer 4 inside the experimental chamber 1, and controls the changes in the water flow field inside the experimental chamber 1 through the second control valve 13.

[0025] A camera device 14 is fixedly installed at the bottom of the freezing tube 2 to observe the stress and breakage of the freezing tube 2 in real time and provide high-definition image feedback.

[0026] The refrigeration system includes a refrigeration unit 15 and a refrigeration pipe 16. The refrigeration unit 15 is connected to the top of the freezing pipe 2 through the refrigeration pipe 16. The refrigeration capacity is adjusted by adjusting the output power of the refrigeration unit 15 to refrigerate and freeze the inside of the freezing pipe 2.

[0027] The experimental chamber 1 is equipped with filter plates 17 around its interior. The filter plate 17 has a filter screen in the middle. The filter screen has an adjustable structure, and the pore size and resistance can be adjusted according to different experimental needs to control the uniformity of humidity distribution.

[0028] The filter plate 17 can move axially to achieve horizontal loading around the freezing tube 2. The top of the experimental chamber 1 is equipped with a pressure loading plate, which can continuously apply vertical load downward to the freezing tube area to simulate the ground pressure environment. At this time, the required ground pressure intensity can be adjusted according to the value measured by the pressure sensor.

[0029] The tide simulation device 5 includes a tide simulation box, a motor, and fan blades. The tide simulation box is located close to the experimental box 1. The tide simulation box contains a motor, and fan blades are installed on the output shaft of the motor. The motor drives the fan blades to simulate the changes in tides.

[0030] The motor speed is adjustable, and by controlling the rotation speed of the fan blades, tidal changes of different intensities and frequencies can be simulated.

[0031] The working process of this invention is as follows:

[0032] Experimental chamber 1 filling and device installation: Based on the required simulated geological environment, fill experimental chamber 1 with soil and rock materials of appropriate types and densities to simulate different geological structures such as sand, clay, and gravel. Install the movable filter plate 17 and filter screen, and adjust the filter screen's resistance parameters according to the required simulated lateral ground stress to ensure realistic ground pressure conditions. Evenly distribute monitoring elements such as temperature sensors, humidity sensors, and pressure sensors around the freezing pipe 2 to ensure comprehensive monitoring of key parameters. Install and connect the tidal simulation device 5, completing a closed-loop connection with the water supply pump 11 and water tank 10.

[0033] System Connection and Parameter Settings: The data processor 7 is connected to the sensor 8 and computer 6 via signal line 9, and the corresponding sampling frequency and recording period are configured. The initial operating power of the refrigeration unit 15 is set, and the sealing performance of the refrigerant circulation system between the freezing tube 2 and the experimental chamber 1 is checked.

[0034] Start the tidal simulation system: turn on the water supply pump 11, simulate the ebb and flow of tides through the tidal simulation device 5, adjust the speed of the motor to control the rotation intensity of the fan blades, thereby adjusting the tidal flow speed and frequency.

[0035] Activate the flow field control system: Adjust the second control valve 13 according to experimental requirements to control the water flow into different areas within the experimental chamber 1, forming the required groundwater flow field. Using feedback from the humidity sensor, adjust the water volume to ensure the humidity within the experimental chamber 1 reaches the set range, accurately simulating actual groundwater humidity conditions. By adjusting the water supply flow rate and direction, regulate the spatial distribution and dynamic changes of the groundwater flow field at different experimental stages.

[0036] Refrigeration system operation: Start the refrigeration unit 15 to gradually lower the temperature, freezing a localized area inside the experimental chamber 1 through the freezing tube 2. Control the refrigeration output power to achieve different freezing rates and temperature distributions according to the needs of each experimental stage. Use a monitoring system to record real-time changes in the temperature, humidity, and stress fields during the freezing process.

[0037] Observation and recording of freezing tube 2: A camera device 14 installed at the bottom of freezing tube 2 can record images of the freezing process in real time. Key parameters such as stress change, freezing range, and freezing rate of freezing tube 2 during the freezing process are acquired by sensor 8 and analyzed and stored in real time on computer 6.

[0038] System shutdown and data export: After the experiment, the refrigeration unit 15, water supply system, and tidal simulation device 5 were shut down sequentially. Data acquisition was stopped, and all monitoring data and image data collected during the experiment were exported. The experimental data were analyzed to obtain the influence of different environmental variables on the freezing effect during the construction of the freezing pipe 2.

[0039] Equipment Disassembly and Reconfiguration: The various functional components of experimental chamber 1 can be disassembled, cleaned, and maintained. The structure of experimental chamber 1, the type and pressure level of the filling soil, tidal strength, and other parameters can be reconfigured according to the needs of the next experiment. The experimental device has good modularity, enabling rapid reconfiguration and parameter resetting, and is suitable for repeated testing needs in various experimental scenarios.

[0040] This invention enables the analysis of the impact of tidal water seepage and scouring on the frozen pipe 2. The experimental apparatus is adjusted and assembled according to different coastal and underground environments for specific experiments. This apparatus provides a simulation experimental device for the construction of the frozen pipe 2 in extreme near-shore environments. It is of great significance for experimental simulation before the construction of the frozen pipe 2 in mines and for the analysis of actual construction safety. This invention can simulate the mechanical response of the entire frozen pipe construction process under ground stress and tidal conditions, and is suitable for the optimization experimental research of underground freezing technology. It has advantages such as high structural integration, strong adaptability, and accurate data monitoring.

Claims

1. A fluid-structure interaction rock mechanics test apparatus for simulating wellbore stability in a freezing construction environment, characterized in that: The test chamber includes a vertically installed freezing pipe in the middle of the chamber. The area enclosed by the freezing pipe serves as the construction zone. The area inside the chamber outside the freezing pipe is filled with soil and rock material as an aquifer. A refrigeration system is connected to the top of the freezing pipe. A tide simulation device is installed on one side of the test chamber. A water supply system is connected to both the test chamber and the tide simulation device. A monitoring system is installed around the freezing pipe.

2. The fluid-structure interaction rock mechanics testing device for simulating wellbore stability during freezing construction according to claim 1, characterized in that: The monitoring system includes a computer, a data processor, and sensors. Several sensors are installed around the freezing tube. The output of the sensors is connected to the input of the data processor, and the output of the data processor is connected to the computer.

3. The fluid-structure interaction rock mechanics testing device for simulating wellbore stability during freezing construction according to claim 2, characterized in that: The sensors include a temperature sensor, a humidity sensor, and a pressure sensor. The signal output terminals of the temperature sensor, humidity sensor, and pressure sensor are connected to the input terminal of the data processor via signal lines.

4. The fluid-structure interaction rock mechanics testing device for simulating wellbore stability during freezing construction according to claim 1, characterized in that: The water supply system includes a water tank, a water pump, and a first control valve. The tidal simulation device is connected to the water tank via the first control valve and the water pump. The water tank is connected to the flow field control system inside the experimental chamber via a water pipe. The flow field control system includes several capillary tubes installed in the aquifer, and a second control valve is installed on the water pipe.

5. The fluid-structure interaction rock mechanics testing device for simulating wellbore stability during freezing construction according to claim 1, characterized in that: A camera device is fixedly installed at the bottom of the freezing tube to observe the stress and cracking of the freezing tube in real time and provide high-definition image feedback.

6. The fluid-structure interaction rock mechanics testing device for simulating wellbore stability during freezing construction according to claim 1, characterized in that: The refrigeration system includes a refrigeration unit and refrigeration pipes, with the refrigeration unit connected to the top of the freezing pipes via the refrigeration pipes.

7. The fluid-structure interaction rock mechanics testing device for simulating wellbore stability during freezing construction according to claim 1, characterized in that: The experimental chamber is equipped with filter plates around its interior, with a filter screen in the middle. The filter screen has an adjustable structure, allowing the pore size and resistance to be adjusted according to different experimental needs to control the uniformity of humidity distribution.

8. The fluid-structure interaction rock mechanics testing device for simulating wellbore stability during freezing construction according to claim 7, characterized in that: The filter plate can move axially to apply horizontal load around the freezing tube. The top of the experimental chamber is equipped with a pressure loading plate, which can continuously apply vertical load downward to the freezing tube area to simulate the ground pressure environment.

9. The fluid-structure interaction rock mechanics testing device for simulating wellbore stability during freezing construction according to claim 1, characterized in that: The tide simulation device includes a tide simulation box, a motor, and fan blades. The tide simulation box is located close to the experimental chamber. The motor is installed inside the tide simulation box, and fan blades are installed on the output shaft of the motor. The motor drives the fan blades to simulate the changes in tides.

10. The fluid-structure interaction rock mechanics testing device for simulating wellbore stability during freezing construction according to claim 9, characterized in that: The motor speed is adjustable, and by controlling the rotation speed of the fan blades, tidal changes of different intensities and frequencies can be simulated.

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