A test device for vertical shaft wellbore surrounding rock-lining thermal interaction and a use method thereof

Abstract

The application discloses a kind of vertical shaft shaft wall rock-lining thermal interaction test device and use method, it is related to mine construction engineering field.The thermal evolution characteristics of deep vertical shaft wall rock unloading cooling process, the thermal interaction between wall rock-lining can be tested and analyzed in laboratory.According to the following method: step one: test device assembly;Step two: wall rock initial state simulation;Step three: wall rock pressure relief cooling process;Step four: concrete shaft lining pouring;Step five: thermal test analysis.Application of the device for testing and analysis, the thermal response characteristics of wall rock unloading in high-temperature environment, the thermal interaction law between wall rock-lining, for accurately evaluating the stress condition of shaft lining under thermal coupling conditions of deep vertical shaft, lay a foundation.

Description

Technical Field

[0001] This invention relates to the field of mining construction engineering. Background Technology

[0002] As mineral resource development continues to advance deeper, the construction of kilometer-deep vertical shafts has gradually become an important part of modern mining engineering. The shaft walls of deep shafts are not only affected by the geostress of the surrounding rock but also by the thermal stress generated by changes in the temperature field. The interaction between the surrounding rock and the lining in the high-temperature environment of deep shafts is a typical thermo-mechanical coupling process. Changes in the temperature field cause the surrounding rock and lining structure to expand or contract, thereby altering the stress state of the shaft walls and affecting the safety of the shaft.

[0003] Currently, research on the thermodynamic interaction between the surrounding rock and lining of deep vertical shafts is relatively limited. Experiments on this interaction are mainly based on constant ambient temperature environments, neglecting the influence of high-temperature and variable-temperature environments at depth. This may lead to deviations in the obtained wellbore stress data from actual operating conditions, affecting wellbore engineering safety or causing material waste. Existing research on the stress on vertical shaft walls does not consider the impact of temperature changes in experimental testing, which is detrimental to a deeper understanding of the unloading characteristics of the surrounding rock and the thermodynamic interaction between the surrounding rock and the wellbore in variable-temperature environments.

[0004] Therefore, those skilled in the art urgently need to develop an experimental device that can realistically simulate the thermal interaction between the surrounding rock and lining of deep shafts, so as to provide a scientific basis for shaft support design. Summary of the Invention

[0005] To address the above problems, this invention proposes a test device and method for the thermodynamic interaction between the surrounding rock and the lining of a vertical shaft. This device can be used to test and analyze the thermodynamic evolution characteristics of the unloading and cooling process of the surrounding rock in a deep vertical shaft, as well as the thermodynamic interaction between the surrounding rock and the lining, in a laboratory setting.

[0006] The technical solution of this invention is as follows: It is carried out in the following manner: Step 1: Assemble the testing device; A cylindrical surrounding rock sample 2 is placed in a cylindrical test chamber, and the two are set coaxially. Place the outer annular flexible hydraulic bladder 3 in the annular gap between the two; An inner-side controlled flexible hydraulic bladder 1 was placed inside the cylindrical surrounding rock sample 2; Temperature sensor 4 and stress sensor 5 are embedded in the upper end of the cylindrical surrounding rock sample 2 by drilling, and connected to the data acquisition instrument through sensor wires. The drilled holes were sealed with cement mortar, and an insulation layer was installed at the upper end of the box. Connect the outer annular flexible hydraulic bladder 3 and the inner flexible hydraulic bladder 1 to the hydraulic pressurization system; Also prepare 9 concrete well wall formwork and 10 air blowing temperature control devices for later use; Step 2: Simulation of the initial state of the surrounding rock; Hydraulic oil is simultaneously injected into the outer annular flexible hydraulic bladder 3 and the inner flexible hydraulic bladder 1 using a hydraulic pressurization system. The hydraulic oil is heated by a heating device inside the hydraulic system, and pressurization is carried out after the temperature reaches the target temperature. The pressure and temperature applied by the two hydraulic bladders are set according to the geostress and geothermal conditions of the strata where the shaft is located. Based on the temperature and pressure test results, once the temperature and pressure stabilize, it can be determined that the initial state simulation has been achieved. Step 3: Decompression and cooling process of surrounding rock; The inner controlled flexible hydraulic bladder 1, which is placed inside the surrounding rock sample 2, is depressurized. After depressurization, the inner controlled flexible hydraulic bladder 1 is removed. The inner controlled flexible hydraulic bladder 1 is not added after removal. This removal process simulates the unloading of the surrounding rock during excavation. Low-temperature air was blown into the inside of the surrounding rock sample 2 using the air blowing temperature control device 10 to simulate the cooling process of the actual working face. During this process, temperature sensors and stress sensors embedded in the surrounding rock sample 2 are used to monitor the evolution of the temperature field and stress field. Step 4: Concrete well wall pouring; A concrete well wall template 9 was arranged inside the surrounding rock sample 2. Then, the prepared concrete was poured into the annular gap between the concrete well wall template 9 and the surrounding rock sample 2 and stirred slightly. Temperature sensor 4 and stress sensor 5 are respectively arranged on the inner wall surface of the surrounding rock sample 2 and in the concrete pouring area, and are connected to the data acquisition instrument through sensor wires. Low-temperature air is continuously blown into the inside of the concrete pouring area using the air blowing temperature control device 10. During this process, temperature sensors and stress sensors are used to record the changes in temperature and stress fields in the surrounding rock sample 2 and the concrete. After the concrete well wall 8 has initially set, remove the concrete well wall formwork 9 and continue to conduct temperature and stress tests. Step 5: Thermal testing and analysis; The analysis of the test results mainly focused on three stages: stage one was the unloading and cooling stage of the surrounding rock (step three); stage two was the setting stage of the concrete well wall (step four); and stage three was the stage where the surrounding rock and the concrete well wall shared the load. The thermal evolution characteristics in these three stages were analyzed using the temperature and stress data obtained from the tests. The flexible hydraulic bladder 1, which was removed from the inner side of the surrounding rock in all three stages, was not repositioned.

[0007] To complement the above experimental procedures, a single mechanical test was added at room temperature without temperature control. The steps for this test were the same as steps one through five, except that temperature control was no longer performed during the process, and the oil temperature was the same as the ambient temperature. By comparing the thermodynamic response results with the results of the single mechanical test, the characteristics of the effect of temperature change on stress evolution were clarified, laying the foundation for wellbore design under thermo-mechanical coupling conditions.

[0008] The test device includes a cylindrical test chamber, in which the surrounding rock sample 2 is coaxially arranged. An outer annular flexible hydraulic bladder 3 is provided between the surrounding rock sample 2 and the test chamber. In the initial state simulation stage of the surrounding rock, an inner flexible hydraulic bladder 1 is also provided on the inner side of the surrounding rock sample 2. Both the outer annular flexible hydraulic bladder 3 and the inner flexible hydraulic bladder 1 are connected to a hydraulic pressurization system. The hydraulic pressurization system is a hydraulic oil supply source and has a heater inside the hydraulic system. The heater heats the hydraulic oil to the target temperature before pressurizing it, thereby controlling the temperature of the hydraulic oil while injecting it. The test apparatus also includes a blowing temperature control device 10, which is a cold air supply source. A duct 11 is installed at the air outlet of the blowing temperature control device 10. During the unloading and cooling stage of the surrounding rock and the setting stage of the concrete well wall, cold air is blown into the inside of the surrounding rock sample 2 or the inside of the concrete well wall 8 through the duct 11. The test apparatus also includes a thermal testing system, which includes multiple temperature sensors 4 and multiple stress sensors 5. The multiple temperature sensors 4 and multiple stress sensors 5 are respectively arranged inside the surrounding rock sample 2, inside the concrete well wall 8, and at the interface between the two. All temperature sensors 4 and stress sensors 5 are connected to a data acquisition instrument through sensor wires.

[0009] Furthermore, the test chamber includes a test chamber base plate 7 and a test chamber side wall 6 fixedly installed on the test chamber base plate 7, and the test chamber side wall 6 is cylindrical.

[0010] Furthermore, the outer annular flexible hydraulic bladder 3 is annular, while the inner flexible hydraulic bladder 1 is cylindrical.

[0011] Furthermore, the hydraulic pressurization system includes a hydraulic oil tank, a hydraulic pump, and hydraulic pipelines. The oil inlet of the hydraulic pump is connected to the hydraulic oil tank through the pipelines, and the oil outlet of the hydraulic pump is connected to the outer annular flexible hydraulic bladder 3 and the inner flexible hydraulic bladder 1 through the hydraulic pipelines. A heater is also fixedly installed inside the hydraulic system.

[0012] Furthermore, the air blowing temperature control device 10 includes a fan, the air inlet of which is connected to air at 26°C to 28°C, and the air outlet of which is connected to the air duct 11.

[0013] This invention takes into account that during deep vertical shaft construction, as the formation temperature gradually increases, the excavation and unloading process of the surrounding rock and the interaction between the surrounding rock and the lining both transform into a thermo-mechanical coupling process. Existing analyses of the interaction between the surrounding rock and the shaft lining from a single mechanical perspective tend to overestimate the forces acting on the shaft wall structure because they do not consider the influence of temperature stress, resulting in material waste and introducing uncertainties into the design of deep vertical shafts.

[0014] This invention provides a testing device and method for studying the thermodynamic evolution of the interaction between the surrounding rock and the well lining under deep, high-geothermal conditions during excavation and unloading of the surrounding rock. By applying this device for testing and analysis, the thermodynamic response characteristics of the surrounding rock unloading and the thermodynamic interaction between the surrounding rock and the lining in a high-geothermal environment can be obtained, laying the foundation for accurately assessing the stress state of the well wall under thermodynamic coupling conditions in deep vertical shafts.

[0015] This invention has the advantages of reasonable structure, strong controllability, high adaptability to strata, and non-interference between internal and external control. It can be widely used in laboratory research on unloading of surrounding rock and thermal interaction between surrounding rock and engineering structure in non-isothermal environments such as shaft walls and tunnel lining. Attached Figure Description

[0016] Figure 1 Schematic diagram of the test system layout during the initial state simulation of surrounding rock; Figure 2 A simplified elevation diagram of the test system layout during concrete pouring after the formwork is in place; In the figure: 1-Inner controlled flexible hydraulic bladder; 2-Surrounding rock sample; 3-Outer annular controlled flexible hydraulic bladder; 4-Temperature sensor; 5-Stress sensor; 6-Side wall of test chamber; 7-Bottom plate of test chamber; 8-Concrete well wall; 9-Concrete well wall template; 10-Air blowing temperature control device; 11-Air duct. Detailed Implementation

[0017] To clearly illustrate the technical features of the present invention, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0018] This invention mainly simulates the evolution of the temperature and stress fields of the surrounding rock and well wall during the process of unloading of surrounding rock, cooling of the working face inside the well, heat release of concrete well wall pouring, and thermal interaction between the surrounding rock and well wall in a deep high geothermal environment, thereby providing basic data for analyzing the thermal response of the surrounding rock and well wall throughout the construction process.

[0019] This invention will contribute to the optimized design of shaft lining in deep, high-geothermal environments and lay the foundation for improving the safety of deep shafts. It also provides experimental equipment and methods for studying the thermal response of surrounding rock unloading and the characteristics of the thermal interaction between surrounding rock and shaft wall during deep shaft construction under different geological conditions and temperature environments.

[0020] Specifically: The test apparatus includes a hydraulic pressurization system, a test chamber, an outer annular controlled flexible hydraulic bladder 3, an inner controlled flexible hydraulic bladder 1, a concrete well wall template 9, an air blowing temperature control device 10, a surrounding rock sample 2, a concrete well wall 8, a thermal testing system, etc.

[0021] The hydraulic pressurization system is a device that provides different hydraulic pressures, and the liquid in the system is preferably hydraulic oil. This hydraulic pressurization system increases the pressure of the hydraulic oil while simultaneously controlling its temperature, thereby providing the flexible hydraulic bladders, namely the outer annular controlled flexible hydraulic bladder 3 and the inner controlled flexible hydraulic bladder 1, with a certain pressure and temperature of liquid.

[0022] The test chamber is used to place the surrounding rock sample 2 and the cast-in-place concrete well wall 8. The chamber is preferably made of high-rigidity materials such as stainless steel. The gap between the chamber and the surrounding rock sample 2 is used to place the outer annular controlled flexible hydraulic bladder 3, while the chamber itself restricts the displacement of the outer annular controlled flexible hydraulic bladder 3 so that the pressure of the outer annular controlled flexible hydraulic bladder 3 can act on the surrounding rock sample 2.

[0023] The outer annular controlled flexible hydraulic bladder 3 is a ring-shaped pressure bladder made of flexible material. The pressure bladder is preferably made of reinforced rubber, high-strength silicone, or other high-pressure resistant materials. The pressure bladder is supplied with liquid at a certain pressure and temperature by a hydraulic pressurization system. The outer annular controlled flexible hydraulic bladder 3 is positioned in the gap between the cylindrical surrounding rock sample 2 and the test chamber to apply a certain pressure to the outside of the surrounding rock sample 2 and control the boundary temperature.

[0024] The inner-side controlled flexible hydraulic bladder 1 is a cylindrical pressure bladder made of flexible material, preferably a reinforced rubber bladder, high-strength silicone capsule, or other high-pressure resistant materials. The pressure bladder is supplied with liquid at a certain pressure and temperature by a hydraulic pressurization system. This cylindrical hydraulic bladder is arranged inside the surrounding rock to apply a certain pressure to the inside of the surrounding rock sample 2 and control the temperature.

[0025] The concrete well wall template 9 is a ring-shaped metal plate arranged inside the surrounding rock sample 2, used for pouring concrete after the pressure inside the surrounding rock sample 2 has been released. The concrete well wall template 9 is preferably made of stainless steel, and its radius is determined according to the size of the concrete well wall 8. It is used to support the concrete area of ​​the well wall and ensure that the concrete well wall 8 can be successfully set.

[0026] The air blowing temperature control device 10 is a device that can provide air at a certain temperature and volume. It is mainly used to control the temperature of the air blown into the inner side of the surrounding rock and well wall structure to simulate the air environment of the internal working face area. This is a small air conditioning system that produces chilled water through a refrigeration cycle. The chilled water is passed into the heat exchange coil to transfer the cooling capacity to the air outside the coil. Then the air is blown out from the air outlet and enters the space inside the surrounding rock and well wall.

[0027] The surrounding rock sample 2 was taken from the construction site of the vertical shaft and processed into a thick-walled cylindrical shape. The outer side of the cylindrical surrounding rock is in close contact with the controlled-temperature flexible hydraulic bladder, and will be subjected to pressure and temperature transmitted by the hydraulic bladder. Simultaneously, an insulation layer is installed at the upper end of the cylindrical surrounding rock. Thus, the unloading thermal response of the surrounding rock and the thermal interaction process between the surrounding rock and the lining are approximately one-dimensional. Based on a scale of 1 / 10 of the actual shaft size, the cylindrical surrounding rock in the test system can be designed with a height of 40cm, an inner diameter of 75cm, and a cylinder thickness of 40cm.

[0028] The concrete well wall 8 is a concrete lining supported by a concrete well wall formwork 9 and poured into the annular gap between the concrete well wall formwork 9 and the surrounding rock sample 2. The concrete well wall 8 poured in the test chamber has the same height as the cylindrical surrounding rock sample 2, and its outer diameter is the same as the inner diameter of the cylindrical surrounding rock sample 2. The pouring thickness can be designed according to the actual well wall thickness. According to the 1 / 10 scaling down, the actual 70cm thick well wall model will be 7cm thick.

[0029] The thermal testing system consists of temperature and stress sensors arranged in the surrounding rock sample 2 and the concrete well wall 8, as well as a data acquisition system. For the surrounding rock sample 2, the temperature sensor 4 and stress sensor 5 are embedded by end drilling; for the concrete well wall 8, the temperature sensor 4 and stress sensor 5 are placed at the interface and in the well wall after the concrete is poured but before it sets.

[0030] The specific steps for using the experimental apparatus are as follows: Step 1: Assemble the testing device; A cylindrical surrounding rock sample 2 is placed inside a cylindrical test chamber, ensuring that the centers of the two samples coincide. An outer annular controlled-flexure hydraulic bladder 3 is placed in the annular gap between the two samples. An inner controlled-flexure hydraulic bladder 1 is placed inside the cylindrical surrounding rock sample 2. Temperature sensors 4 and stress sensors 5 are embedded in the upper part of the cylindrical surrounding rock sample 2 through drilling. The drill holes are sealed with cement mortar, and the various sensor wires and data acquisition instrument are connected. An insulation layer is installed at the upper part of the chamber. Simultaneously, the outer annular controlled-flexure hydraulic bladder 3 and the inner controlled-flexure hydraulic bladder 1 are connected to a hydraulic pressurization system. Also, set up concrete well wall formwork 9 and air blowing temperature control device 10 for later use.

[0031] Step 2: Simulation of the initial state of the surrounding rock; Hydraulic oil is injected into the outer annular controlled flexible hydraulic bladder 3 and the inner controlled flexible hydraulic bladder 1 using a hydraulic pressurization system. The hydraulic oil is heated to the target temperature in the hydraulic pressurization system and then pressurized. The pressure and temperature applied by the two hydraulic bladders are set according to the ground stress and ground temperature conditions of the strata where the shaft is located. When hydraulic pressure is applied, the pressurization process of the outer annular controlled flexible hydraulic bladder 3 and the inner controlled flexible hydraulic bladder 1 is carried out simultaneously, so that the stress response of the cylindrical surrounding rock sample 2 is established instantaneously. However, the heat transfer process takes time. According to the temperature test results, it can be judged that the initial state simulation has been achieved after the temperature stabilizes.

[0032] Step 3: Decompression and cooling process of surrounding rock; The inner controlled flexible hydraulic bladder 1 arranged inside the surrounding rock sample 2 is depressurized. After depressurization, the inner controlled flexible hydraulic bladder 1 is removed. The flexible hydraulic bladder 1 is not added after removal. Low temperature air is blown into the inside of the surrounding rock sample 2 using the blowing temperature control device 10 to simulate the cooling process of the actual working face. According to the actual engineering conditions, the blowing temperature is usually between 26℃ and 28℃. During this process, temperature sensors and stress sensors embedded in the surrounding rock are used to monitor the evolution of the temperature and stress fields.

[0033] Step 4: Concrete well wall pouring; A concrete well wall template 9 was arranged inside the surrounding rock sample 2. Then, prepared concrete was poured into the annular gap between the concrete well wall template 9 and the surrounding rock sample 2, and a small amount of stirring was performed. Temperature sensors 4 and stress sensors 5 were placed at the interface between the surrounding rock and the well wall, and within the well wall concrete. These sensors were then connected to a data acquisition device. During this process, the air-blowing temperature control device 10 inside the concrete well wall template 9 operated continuously. During this process, temperature and stress sensors are used to record the changes in temperature and stress fields in the surrounding rock sample 2 and the concrete. After the concrete well wall 8 has initially set, the concrete well wall formwork 9 is removed, and temperature and stress tests continue.

[0034] Step 5: Thermal testing and analysis; The analysis of the test results mainly focused on three stages: stage one, the unloading and cooling stage of the surrounding rock; stage two, the setting stage of the concrete well wall; and stage three, the stage where the surrounding rock and the concrete well wall jointly bear the load. The thermal evolution characteristics of these three stages were analyzed using the temperature and stress data obtained from the tests. In all three stages, the flexible hydraulic bladder 1, which was removed from the inner side of the surrounding rock, was not repositioned.

[0035] In addition to the above experimental steps, a single mechanical test was added at room temperature without temperature control. The steps for this test were the same as steps one through five, except that temperature control was no longer performed during the process, and the oil temperature was the same as the ambient temperature. By comparing the thermodynamic response results with the results of the single mechanical test, the characteristics of the effect of temperature change on stress evolution were clarified, laying the foundation for wellbore design under thermo-mechanical coupling conditions.

[0036] There are many specific ways to implement this invention. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A test method for the thermal interaction between the surrounding rock and lining of a vertical shaft, characterized in that, Perform the following steps: Step 1: Assemble the testing device; A cylindrical surrounding rock sample (2) is placed in a cylindrical test chamber, and the two are set coaxially. Place the outer annular flexible hydraulic bladder (3) in the annular gap between the two; An inner-side controlled flexible hydraulic bladder (1) is placed inside the cylindrical surrounding rock sample (2); Temperature sensor (4) and stress sensor (5) are embedded in the upper end of the cylindrical surrounding rock sample (2) by drilling, and connected to the data acquisition instrument through sensor wires. The drilled holes were sealed with cement mortar, and an insulation layer was installed at the upper end of the box. Connect the outer annular flexible hydraulic bladder (3) and the inner flexible hydraulic bladder (1) to the hydraulic pressurization system; Also prepare concrete well wall formwork (9) and air blowing temperature control device (10) for later use; Step 2: Simulation of the initial state of the surrounding rock; Hydraulic oil is simultaneously injected into the outer annular flexible hydraulic bladder (3) and the inner flexible hydraulic bladder (1) using a hydraulic pressurization system. The hydraulic oil is heated by a heating device inside the hydraulic system, and pressurization is carried out after the temperature reaches the target temperature. The pressure and temperature applied by the two hydraulic bladders are set according to the geostress and geothermal conditions of the strata where the shaft is located. Based on the temperature and pressure test results, once the temperature and pressure stabilize, it can be determined that the initial state simulation has been achieved. Step 3: Decompression and cooling process of surrounding rock; The controlled flexible hydraulic bladder (1) arranged inside the surrounding rock sample (2) was depressurized. After the depressurization was completed, the inner controlled flexible hydraulic bladder (1) was removed. The inner controlled flexible hydraulic bladder (1) was not added after it was removed. This removal process simulated the unloading of the surrounding rock during excavation. Low-temperature air was blown into the inside of the surrounding rock sample (2) using a blowing temperature control device (10) to simulate the cooling process of the actual working face; During this process, temperature sensors and stress sensors embedded in the surrounding rock sample (2) are used to monitor the evolution of the temperature field and stress field. Step 4: Concrete well wall pouring; A concrete well wall template (9) is arranged inside the surrounding rock sample (2). Then, the prepared concrete is poured into the annular gap between the concrete well wall template (9) and the surrounding rock sample (2) and stirred slightly. Temperature sensors (4) and stress sensors (5) are respectively arranged on the inner wall of the surrounding rock sample (2) and in the concrete pouring area, and connected to the data acquisition instrument through sensor wires. Low-temperature air is continuously blown into the inside of the concrete pouring area using the air blowing temperature control device (10); During this process, temperature sensors and stress sensors are used to record the changes in temperature and stress fields in the surrounding rock sample (2) and concrete; After the concrete well wall (8) has initially set, remove the concrete well wall formwork (9) and continue to conduct temperature and stress tests; Step 5: Thermal testing and analysis; The analysis of the test results mainly focuses on three stages: stage one is the unloading and cooling stage of the surrounding rock in step three; stage two is the setting stage of the concrete well wall in step four; and stage three is the stage where the surrounding rock and the concrete well wall bear the load together. The thermal evolution characteristics in these three stages are analyzed using the temperature and stress data obtained from the test. In all three stages, the flexible hydraulic bladder (1) inside the surrounding rock is removed and not rearranged. To complement the above experimental procedures, a single mechanical test was added at room temperature without temperature control. The steps for this test were the same as steps one through five, except that temperature control was no longer performed during the process, and the oil temperature was the same as the ambient temperature. By comparing the thermodynamic response results with the results of the single mechanical test, the characteristics of the effect of temperature change on stress evolution were clarified, laying the foundation for wellbore design under thermo-mechanical coupling conditions.

2. A test apparatus for implementing the test method of claim 1 regarding the thermal interaction between the surrounding rock and lining of a vertical shaft, characterized in that, The test device includes a cylindrical test chamber, in which the surrounding rock sample (2) is coaxially arranged. An outer annular controlled flexible hydraulic bladder (3) is provided between the surrounding rock sample (2) and the test chamber. In the initial state simulation stage of the surrounding rock, an inner controlled flexible hydraulic bladder (1) is also provided on the inner side of the surrounding rock sample (2). The outer annular control flexible hydraulic bladder (3) and the inner control flexible hydraulic bladder (1) are both connected to a hydraulic pressurization system. The hydraulic pressurization system is a hydraulic oil supply source and has a heater inside the hydraulic system. The heater heats the hydraulic oil to the target temperature before pressurizing it, thereby controlling the temperature of the hydraulic oil while injecting it. The test apparatus also includes a blowing temperature control device (10), which is a cold air supply source. A duct (11) is installed at the air outlet of the blowing temperature control device (10). During the unloading and cooling stage of the surrounding rock and the setting stage of the concrete well wall, cold air is blown to the inside of the surrounding rock sample (2) or the inside of the concrete well wall (8) through the duct (11). The test apparatus also includes a thermal testing system, which includes multiple temperature sensors (4) and multiple stress sensors (5). The multiple temperature sensors (4) and multiple stress sensors (5) are respectively arranged inside the surrounding rock sample (2), inside the concrete well wall (8), and at the interface between the two. All temperature sensors (4) and stress sensors (5) are connected to the data acquisition instrument through sensor wires.

3. The experimental apparatus for the thermal interaction between the surrounding rock and lining of a vertical shaft according to claim 2, characterized in that, The test chamber includes a test chamber base plate (7) and a test chamber side wall (6) fixedly installed on the test chamber base plate (7). The test chamber side wall (6) is cylindrical.

4. The experimental apparatus for the thermal interaction between the surrounding rock and lining of a vertical shaft according to claim 2, characterized in that, The outer annular flexible hydraulic bladder (3) is annular, and the inner flexible hydraulic bladder (1) is cylindrical.

5. The experimental apparatus for the thermal interaction between the surrounding rock and lining of a vertical shaft according to claim 2, characterized in that, The hydraulic pressurization system includes a hydraulic tank, a hydraulic pump and hydraulic pipelines. The inlet of the hydraulic pump is connected to the hydraulic tank through the pipelines. The outlet of the hydraulic pump is connected to the outer annular controlled flexible hydraulic bladder (3) and the inner controlled flexible hydraulic bladder (1) through the hydraulic pipelines. A heater is also fixedly installed inside the hydraulic system.

6. The experimental apparatus for the thermal interaction between the surrounding rock and lining of a vertical shaft according to claim 2, characterized in that, The air blowing temperature control device (10) includes a fan, the air inlet of which is connected to air at 26°C to 28°C, and the air outlet of which is connected to the air duct (11).

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