Temperature-field-controllable rock material thermal-mechanical coupling damage mechanism experimental device and method

Abstract

The invention provides a temperature-field-controllable rock material thermal-mechanical coupling damage mechanism experimental device and method, and belongs to the technical field of rock thermal shock. The device comprises a loading platform which is provided with a supporting unit and a pressing unit, and the pressing unit can move towards the supporting unit so as to load axial pressure on a rock sample placed on the supporting unit; the heating module is used for carrying out heating and heat preservation treatment on the upper section of the rock sample; the cooling module is used for cooling and preserving heat of the lower section of the rock sample; the isolation module is used for isolating the middle section of the rock sample, is provided with a temperature field monitoring unit and is used for monitoring the temperature gradient change of each part in the rock sample in real time; the heating module, the cooling module and the isolation module cooperate with each other and are used for simulating the temperature condition in the underground rock. According to the method, the distribution condition of the internal temperature field in the rock thermal shock process can be quantitatively represented through experiments, and people can deeply understand the action mechanism of rock thermal shock damage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rock thermal shock, and in particular to a rock material thermal-mechanical coupling damage mechanism experiment device and method with controllable temperature field. BACKGROUND

[0002] Thermal shock research has important scientific significance in the field of deep resource development, and rock thermal shock phenomenon has become a widely concerned problem in the field of rock engineering and has developed into one of the more active research directions in the field of rock mechanics. During the thermal shock process, the temperature gradient distribution inside the rock can represent the heat transfer state and thus reflect the thermal shock effect, which is a key indicator for evaluating the distribution of rock thermal shock damage and cracking and the integrity. Under the current technical conditions, there is still a lack of perfect experimental methods and supporting equipment that can accurately capture the dynamic change process of the internal temperature field of the rock. SUMMARY

[0003] Therefore, in order to solve the problem that the prior art lacks experimental devices and methods that can accurately capture the dynamic change process of the internal temperature field of the rock, the present application provides a rock material thermal-mechanical coupling damage mechanism experiment device and method with controllable temperature field. The loading platform is used to perform mechanical experiments on the rock test under different pressures, the heating module is used to heat the upper section of the rock sample, the cooling module is used to cool the lower section of the rock sample, and the isolation module is used to simulate the internal temperature of the rock in the earth bottom. The temperature field monitoring unit can be used to monitor the internal temperature field change of the rock sample and the subsequent change of the mechanical properties of the rock material, different heating temperatures and cooling temperatures can be set to realize different temperature gradients inside the rock sample, and the mechanical property change and damage mechanism of the rock material under the thermal-mechanical coupling condition can be found out. The distribution of the internal temperature field of the rock during the thermal shock process can be quantitatively characterized through experiments, which helps people to better understand the action mechanism of the rock thermal shock damage.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: In a first aspect, the present application provides a rock material thermal-mechanical coupling damage mechanism experiment device with controllable temperature field, comprising: A loading platform having a support unit and a compression unit, the compression unit being capable of moving towards the support unit to load the rock sample placed on the support unit with axial pressure; A heating module for heating and heat preservation of the upper section of the rock sample; A cooling module for cooling and heat preservation of the lower section of the rock sample; An isolation module for isolating the middle section of the rock sample, having a temperature field monitoring unit for real-time monitoring of the temperature gradient change of each part inside the rock sample; The heating module, cooling module, and isolation module work together to simulate the temperature conditions inside rocks underground.

[0005] Preferably, the temperature field monitoring unit includes multiple temperature sensors, which are used to measure the temperature at different locations of the rock sample.

[0006] Preferably, the heating module includes: A heating box is fitted onto the upper section of the rock sample, allowing the pressing unit to enter and press against the upper end of the rock sample; A heating element is disposed inside the heating box and is used to control the temperature inside the heating box; A heat insulation shell covers the outside of the heating box to insulate it from heat loss and prevent heat loss from the heating box.

[0007] Preferably, the heating module further includes: The first sealing structure is used to seal the contact points between the heating module, the clamping unit, and the rock sample to prevent heat loss.

[0008] Preferably, it further includes: The exhaust unit is connected to the heating box.

[0009] Preferably, the cooling module includes: The insulated box has multiple insulation layers; The cooling unit includes multiple cold air delivery nozzles arranged in a circular array with the axial central axis of the insulation box as the center.

[0010] Preferably, it further includes: A cold air storage tank is connected to multiple cold air delivery nozzles; A flow regulator is installed on the pipe connecting the cold air storage tank and the cold air delivery nozzle.

[0011] Preferably, it further includes: The waste gas recovery device is used to recover the cooling gas after experimental treatment and reprocess it for reuse.

[0012] Preferably, the isolation module includes: A quartz tube is fitted over the middle section of the rock sample; A heat insulation plug is disposed at the junction of the quartz tube and the heating module; A sealing diaphragm is positioned at the junction of the quartz tube and the cooling module.

[0013] Secondly, the present invention also provides an experimental method for monitoring the mechanical properties of rock materials based on the above-mentioned experimental device for the thermo-mechanical coupling damage mechanism of rock materials with a controllable temperature field, comprising the following steps: Prepare rock sample A and rock sample B from the same rock mass, and perform pre-processing on rock sample A. Place rock sample A on the support unit, move the clamping unit until it is in slight contact with rock sample A, and then assemble the cooling module, the isolation module and the heating module from bottom to top. Place the temperature field monitoring unit, check the airtightness of the isolation module and the heating module, and perform a vacuum process; The required experimental conditions are set, the pressing unit applies external force by pressing down, the heating module heats the upper section of rock sample A, the cooling module cools the lower section of rock sample A, and the temperature gradient change of rock sample A is monitored in real time by the temperature field monitoring unit. Stop the experiment when the preset temperature field environment is reached, and record the experimental conditions and time. Treat rock sample B with the same experimental conditions, time and steps. Mechanical tests were conducted on the rock sample B after experimental treatment, and the experimental data were collected and analyzed.

[0014] The present invention provides an experimental apparatus and method for simulating the thermo-coupling damage mechanism of rock materials with a controllable temperature field. This apparatus simulates the internal temperature of rocks underground through the coordinated use of heating, cooling, and isolation modules, and monitors the temperature gradient changes at various points within the rock sample in real time using a temperature field monitoring unit. This allows for the experimental quantification and characterization of the internal temperature field distribution during rock thermal shock, contributing to a deeper understanding of the mechanism of rock thermal shock damage. Compared to existing technologies, this invention offers the following advantages: Simulating complex thermo-mechanical coupling environments: This invention provides axial pressure through a loading platform, and combines heating, isolation and cooling modules to simulate complex thermo-mechanical coupling environments. It can accurately simulate the real stress environment of underground rocks under temperature gradient and geostress, solving the problem that existing technologies cannot reproduce extreme working conditions.

[0015] The temperature field monitoring unit uses multiple temperature sensors to measure the temperature at different locations on the rock sample, dynamically quantifying changes in the temperature gradient. Combined with the isolation module, it can acquire internal three-dimensional temperature gradient data in real time and accurately, providing quantitative evidence for the study of thermal shock damage mechanisms.

[0016] The heating module achieves efficient heating and low loss through heating elements, heat insulation shell and first sealing structure; the cooling module adopts circumferential array cold air nozzles and flow regulator to ensure independent temperature control stability of upper and lower sections, significantly improve temperature control accuracy and uniformity, and achieve efficient temperature control and heat loss suppression.

[0017] The exhaust unit regulates the pressure of the heating box to avoid the risk of overheating; the waste gas recovery device recycles the cooling gas, reducing energy consumption and emissions, and taking into account both experimental safety and environmental protection.

[0018] The isolation module blocks temperature crosstalk between the upper and lower sections through heat-insulating plugs and sealing diaphragms, while the quartz tube maintains a stable environment in the middle section. The dual-sample design (A for monitoring the temperature field / B for testing mechanical properties) ensures consistency of experimental conditions, enabling correlation analysis between the temperature field and mechanical properties, and significantly improving data reliability and research efficiency.

[0019] In summary, this invention provides a method for conducting mechanical experiments on rocks under different pressures using a loading platform. A heating module heats the upper section of the rock sample, while a cooling module cools the lower section. An isolation module further simulates the internal temperature conditions of rocks underground. A temperature field monitoring unit allows for real-time monitoring of changes in the internal temperature field of the rock sample and subsequent changes in the mechanical properties of the rock material. By setting different heating and cooling temperatures, different temperature gradients within the rock sample can be achieved, revealing the changes in mechanical properties and damage mechanisms of rock materials under thermo-mechanical coupling conditions. This allows for the experimental quantitative characterization of the internal temperature field distribution during rock thermal shock, contributing to a deeper understanding of the mechanisms of rock thermal shock damage. Attached Figure Description

[0020] Figure 1 This is a perspective view of the present invention; Figure 2 This is a schematic diagram of the sealed assembly structure of the heating module and the clamping unit; Figure 3 This is a schematic diagram of the assembly structure of the heating module, cooling module, and isolation module; Figure 4 This is a schematic diagram of the cooling module and the air circulation structure. Figure 5 This is a schematic diagram of the layout of a multi-point temperature field monitoring unit.

[0021] In the diagram, 1. Loading platform; 12. Hydraulic control system; 13. Clamping unit; 14. Support unit; 2. Heating module; 21. Heating box; 22. Heating element; 23. Insulation shell; 24. First sealing structure; 25. Exhaust unit; 3. Isolation module; 31. Quartz tube; 32. Insulation plug; 33. Sealing diaphragm; 4. Cooling module; 41. Insulation box; 42. Cold air delivery nozzle; 43. Flow regulator; 44. Cold air storage tank; 45. Waste gas recovery device; 46. Graphite sealing ring; 5. Temperature field monitoring unit; 51. Temperature sensor; 52. Data acquisition instrument; 53. Digital converter; 6. Rock sample. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] like Figures 1-2 As shown, this invention provides an experimental apparatus for the thermo-mechanical coupling damage mechanism of rock materials with a controllable temperature field, comprising: The loading platform 1 includes a support unit 14 and a clamping unit 13. The clamping unit 13 can move towards the support unit 14 to apply axial pressure to the rock sample 6 placed on the support unit 14. A heating module 2 is used to heat and maintain the upper section of the rock sample 6. A cooling module 4 is used to cool and maintain the lower section of the rock sample 6. An isolation module 3 is used to isolate the middle section of the rock sample 6 and includes a temperature field monitoring unit 5 for real-time monitoring of temperature gradient changes throughout the rock sample 6. The heating module 2, cooling module 4, and isolation module 3 work together to simulate the internal temperature conditions of rock underground.

[0026] This invention utilizes a loading platform 1 to conduct mechanical experiments on rocks under different pressures. A heating module 2 heats the upper section of the rock sample 6, while a cooling module 4 cools the lower section. An isolation module further simulates the internal temperature of rocks underground. A temperature field monitoring unit 5 monitors real-time changes in the internal temperature field of the rock sample 6 and the resulting changes in the mechanical properties of the rock material. By setting different heating and cooling temperatures, different temperature gradients are achieved within the rock sample 6, revealing the changes in mechanical properties and damage mechanisms of the rock material under thermo-mechanical coupling conditions. This allows for the experimental quantification and characterization of the internal temperature field distribution during rock thermal shock, contributing to a deeper understanding of the mechanisms of rock thermal shock damage.

[0027] In this invention, the loading platform 1 preferably includes a hydraulic control system 12, which drives the clamping unit 13 to move closer to or further away from the support unit 14. The main body of the hydraulic control system 12 is an electro-hydraulic servo actuator. This system adopts an electro-hydraulic servo closed-loop control structure, consisting of a multi-channel digital control system, a two-channel loading test system, and a data analysis and processing system. Its multi-channel digital control system supports load, displacement, and strain control, as well as dual-mode (simultaneous load / displacement control) and computational control modes, allowing users to define physical quantities as closed-loop parameters. The hydraulic control system 12 drives the clamping unit 13 to move axially, applying axial force to the rock sample 6, and working in conjunction with the support unit 14 to clamp the rock sample 6. This provides axial pressure, simulating a deep-ground stress environment.

[0028] The clamping unit 13 is a high-temperature resistant pressure plate connected to the hydraulic control system 12. During the experiment, the clamping unit 13, which provides external pressure to the rock sample 6, has a ring of cooling nozzles around its outer periphery. This effectively reduces the high-temperature impact of the heating module 2 on the clamping unit 13, thereby protecting the various sensors inside the clamping unit 13. The support unit 14 is preferably a low-temperature resistant tray fixed to the base of the loading platform 1. Together with the clamping unit 13, it fixes the rock sample 6 and, together with the cooling module 4, seals the lower section of the rock sample 6. The graphite sealing ring 46 seals the contact points between the support unit 14, the rock sample 6, and the cooling module 4.

[0029] During the experimental preparation phase, the hydraulic control system 12 needs to be debugged to ensure that the clamping unit 13 and the support unit 14 jointly fix the rock sample 6. In the experiment, the loading platform 1 can provide different load environments for the rock sample 6, thereby simulating the compression of rocks in real-world environments.

[0030] like Figure 5As shown, in this invention, the temperature field monitoring unit 5 includes multiple temperature sensors 51, which are used to measure the temperature at different locations on the rock sample 6. The temperature field monitoring unit 5 also includes a data acquisition unit 52 and a digital converter 53. The temperature sensors 51 are K-type armored thermocouples.

[0031] K-type sheathed thermocouples are inserted into the prepared rock sample 6 at different depths. After being fixed with adhesive, the internal temperature gradient and temperature field changes of the rock sample 6 can be monitored in real time. The K-type sheathed thermocouples at different depths represent different temperature field data of the rock sample 6 in the transverse and longitudinal directions. This provides a relatively intuitive representation of the internal temperature gradient changes of the rock sample 6 under different external environments. Laterally, it represents the temperature gradient change from the outer surface of the rock sample 6 cross-section to the core; longitudinally, it represents the temperature gradient change from a high-temperature environment to a low-temperature environment. This allows for further investigation into the influence of different temperature fields on the mechanical properties of the rock, and can also study the influence of different bedding planes on the internal temperature field of the rock under the same external environment. The data acquisition instrument 52 is connected to the K-type sheathed thermocouples via a data cable harness to receive the probe monitoring data. The digital converter 53 is connected to the data acquisition instrument 52 and a personal computer, which can decode and convert the acquired data to professional software on the personal computer.

[0032] like Figure 3 As shown, the present invention provides an embodiment of a heating module 2, the heating module 2 comprising: A heating box 21 is fitted onto the upper section of the rock sample 6, allowing the pressing unit 13 to enter and press against the upper end of the rock sample 6. A heating element 22 is disposed inside the heating box 21 and is used to control the temperature inside the heating box 21. A heat insulation shell 23 covers the outside of the heating box 21 and is used for heat insulation to prevent heat loss from the heating box 21. In this invention, the heating module 2 further includes: The first sealing structure 24 is used to seal the contact points between the heating module 2, the pressing unit 13, and the rock sample 6 to prevent heat loss.

[0033] This invention also includes: The exhaust unit 25 is connected to the heating box 21.

[0034] Specifically, the heating module 2 includes a heating box 21, a heating element 22, and a heat insulation shell 23. The heating element 22 is disposed inside the heating box 21 and is used to control the temperature inside the heating box 21. The heat insulation shell 23 covers the outside of the heating box 21. The heating element 22 heats the upper part of the rock sample 6 entering the heating box 21, and the heat insulation shell 23 prevents rapid heat loss and ensures the stability of the experiment.

[0035] Preferably, the upper side of the heating box 21 is provided with a first slot for the pressing unit 13 to enter. A first sealing structure 24 is provided at the contact point between the first slot and the pressing unit 13. The pressing unit 13 enters the heating module 2 (heating box 21) through the first slot and presses against the upper end of the rock test. The lower side of the heating box 21 is provided with a second slot for the rock sample 6 to enter. The second slot also has a first sealing structure 24 at the contact point between the second slot and the rock sample 6. The support unit 14 enters the cooling module 4 through the second slot and presses against the lower end of the rock test.

[0036] An exhaust unit 25 communicating with the interior of the heating box 21 is also provided outside the heating box 21, and a pressure gauge is preferably installed at the outlet of the exhaust unit 25. An isolation cavity is formed between the inner and outer sides of the heat insulation shell 23, and the isolation cavity is filled with heat insulation material. The inner shell of the heat insulation shell 23 is responsible for accommodating the heating element and the heat-treated workpiece, while the outer shell provides heat insulation protection. A heat insulation layer is formed between the inner and outer shells by filling with heat insulation material and a fan is installed, which allows for rapid heating and cooling, effectively reducing heat loss while providing better insulation and safety.

[0037] The heating box 21 is preferably made of alumina ceramic fiber. Alumina fiber has low thermal conductivity, so the heating box 21 itself absorbs less heat and can transfer heat to the material inside the heating box 21 more quickly. At the same time, it has good thermal stability and uniform temperature distribution during heating, which can effectively avoid the problem of local overheating or uneven temperature. The heating box 21 is equipped with a temperature sensor 51 to obtain the temperature inside the box in real time during the experiment.

[0038] The heating element 22 is preferably a silicon carbide rod, and more preferably, the heating element 22 is a U-shaped silicon carbide rod, which is set in a specific inner groove of the heating box 21, so as to quickly and stably heat the experimental material and accurately control and adjust the temperature of each section.

[0039] The first sealing structure 24 is preferably a graphite sealing ring 46. The first sealing structure 24 is a detachable component used to seal the contact points between the compression unit 13 and the rock sample 6 and the sample heating module 2, preventing the escape of heated gas from affecting the experiment. The exhaust unit 25 is connected to the interior of the heating box 21 to prevent hot gas leakage and balance the pressure inside the box. The pressure gauge on it is a mechanical pressure gauge used to detect the pressure inside the heating box 21. After the rock sample 6 is fixed, the graphite sealing ring 46 is assembled and seals the components, the junction of the rock sample 6 and the heating box 21, forming a sealed space. After heating for a period of time, the exhaust unit 25 is opened.

[0040] like Figure 4As shown, in this invention, the cooling module 4 includes an insulation box 41 with multiple insulation layers; and a cooling unit including multiple cold air delivery nozzles 42 arranged in a circular array with the axial central axis of the insulation box 41 as the center. Preferably, it also includes: a cold air storage tank 44, connected to the multiple cold air delivery nozzles 42; and a flow regulator 43, disposed on the pipe connecting the cold air storage tank 44 and the cold air delivery nozzles 42. Preferably, it also includes: a waste gas recovery device 45, used to recover the cooling gas after experimental treatment for reprocessing and recycling.

[0041] like Figures 3-4 As shown, the present invention provides a specific embodiment of the cooling module 4, specifically: The cooling module 4 includes an insulation box 41 and a cooling unit. The cooling unit includes multiple cold air delivery nozzles 42. The cold air delivery nozzles 42 enter the insulation box 41 and are arranged in a circular array with the axial central axis of the insulation box 41 as the center.

[0042] The cooling unit also includes a cold air storage tank 44 and a flow regulator 43. The flow regulator 43 is installed on the pipe connecting the cold air storage tank 44 and the cold air delivery nozzle 42.

[0043] The cooling module 4 also includes a waste gas recovery device 45. The insulation box 41 has multiple insulation layers filled with low thermal conductivity insulating material, effectively maintaining a cooling environment and preventing the cooling gas from rapidly heating up and reducing experimental effectiveness. A temperature sensor 51 installed in the insulation box 41 can acquire the temperature inside the chamber in real time during the experiment. Cold gas delivery nozzles 42 are evenly distributed along the inner wall of the insulation box 41, providing 360° all-around cooling for the experimental rock sample 6.

[0044] The flow regulator 43 is used to adjust the cooling gas input flow rate in real time according to the temperature of the insulation box 41 to maintain a cooling atmosphere. The cold gas storage tank 44 is connected to the flow regulator 43 and the cold gas delivery nozzle 42 via pipelines and is used to store and deliver the cooling gas. The waste gas recovery device 45 can collect and recover the cooling gas after experimental treatment for reprocessing and recycling. The waste gas recovery device 45 and the cold gas storage tank 44 are placed next to the loading platform 1.

[0045] In this invention, the isolation module includes: a quartz tube 31, fitted onto the middle section of the rock sample 6; a heat insulation plug 32, positioned at the junction of the quartz tube 31 and the heating module 2; and a sealing diaphragm 33, positioned at the junction of the quartz tube 31 and the cooling module 4.

[0046] like Figure 3As shown, this invention provides a specific embodiment of an isolation module, which includes a quartz tube 31, a heat insulation plug 32, and a sealing diaphragm 33. The quartz tube 31 is fitted into the middle section of the rock test. The heat insulation plug 32 is provided at the position where the quartz tube 31 connects with the heating module 2, and the sealing diaphragm 33 is provided at the position where the quartz tube 31 connects with the cooling module 4. An opening is provided on the side of the quartz tube 31, through which a temperature sensor 51 enters the quartz tube 31.

[0047] Quartz tube 31 is positioned between heating module 2 and cooling module 4 to enclose the middle section of rock sample 6. Quartz tube 31 is available in two types: perforated quartz tube 31 and ordinary quartz tube 31. Specifically: The perforated quartz tube 31 is used to monitor the internal temperature field of the rock sample 6. The perforated quartz tube 31 has openings on both sides so that the temperature sensor 51 of the temperature field monitoring unit 5 can be inserted into the quartz tube 31 to monitor the rock sample 6. The bottom has an inner groove to fix the sealing diaphragm 33. A sealing rubber ring is provided at the side opening. At the same time, there is an opening to connect with the external vacuum pump through an air pipe. During the experiment, the perforated quartz tube 31 maintains a vacuum state to reduce the influence of air on the changing temperature field in the middle section of the rock sample 6. Ordinary quartz tube 31 is used in repeated mechanical property experiments after acquiring temperature field data. It has an inner groove at the bottom to fix the sealing diaphragm 33, which together seals the middle section of rock sample 6. The heat insulation plug 32 is a mullite-corundum-alumina ceramic high-temperature furnace plug, located at the junction of rock sample 6 and heating module 2. It rings around rock sample 6 to prevent escaping high-temperature gases from affecting the middle section of rock sample 6, effectively blocking heat exchange between the inside and outside of the furnace. The sealing diaphragm 33 is located at the junction of rock sample 6 and sample cooling module 4. Its outer ring is embedded in the inner groove of the experimental quartz tube 31, and its inner ring rings around the outer edge of rock sample 6. A low-temperature resistant plastic film is placed between the inner and outer rings. While sealing rock sample 6 with the graphite sealing ring 46 and quartz tube 31, it also isolates the middle section of rock sample 6 from escaping low-temperature cooling gases.

[0048] Secondly, the present invention also provides an experimental method for monitoring the mechanical properties of rock materials based on the above-mentioned experimental device for the thermo-mechanical coupling damage mechanism of rock materials with a controllable temperature field, comprising the following steps: Prepare rock sample A and rock sample B from the same rock mass, and perform pre-processing on rock sample A. Place rock sample A on support unit 14, move clamping unit 13 until it is in slight contact with rock sample A, and then assemble cooling module 4, isolation module and heating module 2 from bottom to top. Place the temperature field monitoring unit 5, check the airtightness of the isolation module and the heating module 2, and perform a vacuum process; The required experimental conditions are set, the pressing unit 13 applies external force by pressing down, the heating module 2 heats the upper section of rock sample A, the cooling module 4 cools the lower section of rock sample A, and the temperature gradient change of rock sample A is monitored in real time by the temperature field monitoring unit 5. Stop the experiment when the preset temperature field environment is reached, and record the experimental conditions and time. Treat rock sample B with the same experimental conditions, time and steps. Mechanical tests were conducted on the rock sample B after experimental treatment, and the experimental data were collected and analyzed.

[0049] The specific experiments of this invention are as follows: Step (1): Prepare cooling gas and store it in cold gas storage tank 44; Step (2): Prepare rock sample A and rock sample B from the same rock mass, and perform pre-processing on rock sample A: open a monitoring hole on the side of the upper and lower sections of rock sample A, with a depth reaching the rock core axis; open monitoring holes at equal intervals in the longitudinal direction of the middle section of rock sample A; and open monitoring holes at different depths in the transverse direction of the middle section of rock sample A. Step (3): Place rock sample A at support unit 14, move clamping unit 13 to make slight contact with rock sample A, and assemble cooling module 4 at support unit 14, isolation module that seals the middle section of rock sample A, and heating module 2 at clamping unit 13 in sequence from bottom to top. During the assembly process, install graphite sealing rings 46 and sealing diaphragms 33 to ensure that the upper, middle and lower sections of rock sample A are relatively sealed. Set the temperature sensors 51 in heating module 2 and cooling module 4 in the monitoring holes of the upper and lower sections of rock sample A respectively. Step (4): Assemble the temperature field monitoring unit 5, fix the K-type armored thermocouple inserted into the rock sample A, and ensure the sealed environment of the quartz tube 3 in the middle section of the rock sample A; connect the data acquisition instrument 52, digital converter 53 and personal computer. Step (5): Check the airtightness of the quartz tube 31 and the heating box 21 and perform vacuum treatment. During the experiment, the quartz tube 31 is connected to an external vacuum pump to ensure that the inside of the quartz tube 31 is in a vacuum environment. Step (6): Set the required experimental conditions, press down the clamping unit 13 to apply external force, heat the upper section of rock sample A with heating module 2, and cool the lower section of rock sample A with cooling module 4. At the same time, the temperature gradient change of the middle section of rock sample A is monitored in real time to create a thermo-coupling environment for rock sample A. Step (7): Stop the experiment when the desired temperature field environment is reached, record the experimental conditions and experimental time, and replace the quartz tube 31 with the same experimental conditions, experimental time and experimental steps, that is, use the thermo-coupling environment of rock sample A to treat rock sample B. Step (8): Replace the clamping unit 13 of the sample loading platform 1, and conduct other mechanical tests on the rock sample B after the thermal coupling environment test of rock sample A, and collect and analyze the experimental data. The experimental conditions of rock sample B are determined by rock sample A. Rock sample A has openings that allow multiple temperature probes to be inserted to measure the internal temperature field distribution. However, given the numerous openings in rock sample A, its mechanical properties will be severely affected. Therefore, the mechanical experimental data of rock sample A can only be used as auxiliary data. The mechanical properties of the real rock sample must be measured using rock sample B under the same experimental conditions to ensure the accuracy of the data.

[0050] The above description is merely a preferred embodiment of the present invention. However, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. An experimental apparatus for the thermo-mechanical coupling damage mechanism of rock materials with a controllable temperature field, characterized in that, include: A loading platform having a support unit and a clamping unit, the clamping unit being movable toward the support unit to apply axial pressure to a rock sample placed on the support unit; A heating module is used to heat and keep the upper section of the rock sample warm. The cooling module is used to cool and keep the lower section of the rock sample warm. An isolation module is used to isolate the middle section of the rock sample. It has a temperature field monitoring unit for real-time monitoring of temperature gradient changes at various points inside the rock sample. The heating module, cooling module, and isolation module work together to simulate the temperature conditions inside rocks underground.

2. The experimental apparatus for the thermo-coupling damage mechanism of rock materials with a controllable temperature field according to claim 1, characterized in that, The temperature field monitoring unit includes multiple temperature sensors, which are used to measure the temperature at different locations on the rock sample.

3. The experimental apparatus for the thermo-mechanical coupling damage mechanism of rock materials with a controllable temperature field according to claim 1, characterized in that, The heating module includes: A heating box is fitted onto the upper section of the rock sample, allowing the pressing unit to enter and press against the upper end of the rock sample; A heating element is disposed inside the heating box and is used to control the temperature inside the heating box; A heat insulation shell covers the outside of the heating box to insulate it from heat loss and prevent heat loss from the heating box.

4. The experimental apparatus for the thermo-mechanical coupling damage mechanism of rock materials with a controllable temperature field according to claim 3, characterized in that, The heating module also includes: The first sealing structure is used to seal the contact points between the heating module, the clamping unit, and the rock sample to prevent heat loss.

5. The experimental apparatus for the thermo-coupling damage mechanism of rock materials with a controllable temperature field according to claim 3, characterized in that, Also includes: The exhaust unit is connected to the heating box.

6. The experimental apparatus for the thermo-mechanical coupling damage mechanism of rock materials with a controllable temperature field according to claim 1, characterized in that, The cooling module includes: The insulated box has multiple insulation layers; The cooling unit includes multiple cold air delivery nozzles arranged in a circular array with the axial central axis of the insulation box as the center.

7. The experimental apparatus for the thermo-coupling damage mechanism of rock materials with a controllable temperature field according to claim 6, characterized in that, Also includes: A cold air storage tank is connected to multiple cold air delivery nozzles; A flow regulator is installed on the pipe connecting the cold air storage tank and the cold air delivery nozzle.

8. The experimental apparatus for the thermo-coupling damage mechanism of rock materials with a controllable temperature field according to claim 6, characterized in that, Also includes: The waste gas recovery device is used to recover the cooling gas after experimental treatment and reprocess it for reuse.

9. An experimental apparatus for thermo-mechanical coupling damage mechanism of rock materials with a controllable temperature field according to any one of claims 1-8, characterized in that, The isolation module includes: A quartz tube is fitted over the middle section of the rock sample; A heat insulation plug is disposed at the junction of the quartz tube and the heating module; A sealing diaphragm is positioned at the junction of the quartz tube and the cooling module.

10. An experimental method for monitoring the mechanical properties of rock materials using an experimental apparatus for thermo-mechanical coupling damage mechanism of rock materials based on a controllable temperature field as described in any one of claims 1-9, characterized in that, Includes the following steps: Prepare rock sample A and rock sample B from the same rock mass, and perform pre-processing on rock sample A. Place rock sample A on the support unit, move the clamping unit until it is in slight contact with rock sample A, and then assemble the cooling module, the isolation module and the heating module from bottom to top. Place the temperature field monitoring unit, check the airtightness of the isolation module and the heating module, and perform a vacuum process; The required experimental conditions are set, the pressing unit applies external force by pressing down, the heating module heats the upper section of rock sample A, the cooling module cools the lower section of rock sample A, and the temperature gradient change of rock sample A is monitored in real time by the temperature field monitoring unit. Stop the experiment when the preset temperature field environment is reached, and record the experimental conditions and time. Treat rock sample B with the same experimental conditions, time and steps. Mechanical tests were conducted on the rock sample B after experimental treatment, and the experimental data were collected and analyzed.

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