Ultra-wide temperature range three-field coupling rock shear rheological test device and method

Abstract

The invention discloses an ultra-wide temperature range three-field coupling rock shear rheological test device and method. The device comprises a split type shear box assembly, a quick connection fluid temperature control jacket, a rigidity servo loading system, a seepage and dynamic sealing system, an intelligent synchronous control system and an external temperature control unit. A temperature field is applied through an external temperature control unit, a stress field is applied through a rigidity servo loading system, a seepage field is applied through a seepage and dynamic sealing system, and multi-field coupling control and data acquisition are achieved through an intelligent synchronous control system. The method comprises: installing a rock sample; applying temperature, seepage and load through the systems respectively or in a coupling manner; and the intelligent synchronous control system is used for controlling the multi-field coupling action process so as to research the shear rheological property of the rock in a complex environment. The device can effectively simulate the temperature-seepage-stress three-field coupling effect in the ultra-wide temperature range, and a key technical means is provided for deep ground engineering rock mass stability research.

Description

Technical Field

[0001] This invention relates to the field of rock engineering testing equipment and technology, and in particular to an ultra-wide temperature range three-field coupled rock shear rheology testing device and method. Background Technology

[0002] In major projects such as deep resource extraction, geological disposal of high-level radioactive waste, and geothermal development in cold regions, the rock masses are subjected to extreme and complex environments involving multiple coupled fields, including high temperature, high permeability, high geostress, and freeze-thaw cycles. Their long-term strength, deformation, and fracture behavior are the result of nonlinear responses to the combined effects of multiple physical fields. Studying only a single or two coupled fields cannot reveal the true catastrophic mechanism.

[0003] Existing rock mechanics testing equipment faces significant bottlenecks in simulating such complex environments. While traditional rheometers possess wide temperature range control capabilities, their core design is geared towards homogeneous materials such as polymers, making it impossible to apply high normal stress and seepage pressure to fractured or heterogeneous rock samples. Traditional triaxial or direct shear testers for rocks rarely operate in coupled fields, and their associated temperature control systems suffer from narrow temperature control ranges, poor temperature control accuracy and uniformity, and difficulty in achieving structural compatibility and synchronous control with shear and seepage systems. This makes it impossible to meet the complete simulation requirements from deep high temperatures to surface freeze-thaw cycles. Under the combined effects of temperature alternation, seepage, and shear loads over long periods, traditional rubber seals are prone to aging and failure. The complex temperature control piping and valves integrated into the shear chamber are potential leakage points and maintenance challenges, making it difficult for the equipment to operate stably for complex time-series coupled tests that can last for weeks or even months. Summary of the Invention

[0004] This invention provides an ultra-wide temperature range three-field coupled rock shear rheology testing device and method to overcome the problems of narrow temperature control range, poor temperature control accuracy and uniformity, and difficulty in achieving structural compatibility and synchronous control with shear and seepage systems obtained by traditional testing devices.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: An ultra-wide temperature range three-field coupled rock shear rheology test device includes: a modular shear box assembly, a quick-connect fluid temperature control jacket, a stiffness servo loading system, a seepage and dynamic sealing system, an intelligent synchronous control system, and an external temperature control unit; The assembled shear box assembly contains a rock sample. The assembled shear box assembly is connected to the quick-connect fluid temperature control jacket; The external temperature control unit is connected to the quick-connect fluid temperature control jacket and is used to provide the rock sample with a temperature within a set temperature range through the quick-connect fluid temperature control jacket. The stiffness servo loading system is connected to the assembled shear box assembly and is used to apply normal loads and shear loads to the rock sample set inside the assembled shear box assembly. The seepage and dynamic sealing system is connected to the modular shear box assembly and is used to apply seepage water pressure and air pressure to the rock sample. The intelligent synchronous control system is connected to the external temperature control unit, stiffness servo loading system, and seepage and dynamic sealing system via signal connection.

[0006] Furthermore, the external temperature control unit includes a high-temperature silicone oil storage tank, a high-temperature circulating pump, a high-temperature circulating oil supply pipeline, a high-temperature circulating oil return pipeline, an ethylene glycol solution storage tank, a low-temperature circulating pump, a low-temperature circulating water supply pipeline, and a low-temperature circulating water return pipeline. The high-temperature silicone oil storage tank is equipped with an immersion electric heater inside, and a heating controller, a high-temperature silicone oil outlet, a high-temperature silicone oil inlet, and a high-temperature circulating pump interface on its outer wall. The heating controller is communicatively connected to the intelligent synchronous control system and the immersive electric heater, respectively. The high-temperature silicone oil storage tank is connected to one end of the high-temperature circulating oil supply pipeline via the high-temperature silicone oil outlet, to one end of the high-temperature circulating oil return pipeline via the high-temperature silicone oil inlet, and to the high-temperature circulating pump via the high-temperature circulating pump interface. The other ends of the high-temperature circulating oil supply pipeline and the high-temperature circulating oil return pipeline are respectively provided with a first hydraulic quick-connect male connector and a second hydraulic quick-connect male connector. The ethylene glycol solution storage tank is equipped with a compression refrigeration system inside, and a refrigeration controller, an ethylene glycol solution outlet, an ethylene glycol solution inlet, and a low-temperature circulating pump interface on its outer wall. The refrigeration controller is communicatively connected to both the intelligent synchronous control system and the compression refrigeration system. The ethylene glycol solution storage tank is connected to one end of the low-temperature circulating water supply pipeline through the ethylene glycol solution outlet, to one end of the low-temperature circulating return water pipeline through the ethylene glycol solution inlet, and to the low-temperature circulating pump through the low-temperature circulating pump interface. The other ends of the low-temperature circulating water supply pipeline and the low-temperature circulating water return pipeline are respectively provided with a third hydraulic quick-connect male connector and a fourth hydraulic quick-connect male connector. The first, second, third, and fourth hydraulic quick-connect male connectors are connected to the quick-connect fluid temperature control jacket.

[0007] Furthermore, the high-temperature silicone oil storage tank is used to store silicone oil, and the silicone oil is heated by an immersion electric heater controlled by a heating controller, so that the temperature of the silicone oil can be adjusted between room temperature and 300°C. The ethylene glycol solution storage tank is used to store ethylene glycol aqueous solution. The refrigeration system is controlled by a refrigeration controller to refrigerate the ethylene glycol aqueous solution, so that the temperature of the ethylene glycol aqueous solution can be adjusted between room temperature and -40°C.

[0008] Furthermore, the quick-connect fluid temperature control jacket includes a surrounding housing, a hot serpentine fluid flow channel, a cold serpentine fluid flow channel, a locking mechanism, and a device frame; The surrounding housing includes a first side plate, a second side plate, and a top plate; The first side panel includes a first splicing plate and a second splicing plate; The second side panel includes a third splicing panel and a fourth splicing panel; The top plate is fixed perpendicularly to the top of the first splicing plate and the top of the third splicing plate at both ends, respectively; the second splicing plate and the fourth splicing plate are disposed on one side of the top plate; The thermal serpentine fluid flow channel is sequentially arranged on one side of the assembled shear box assembly of the second splicing plate, the first splicing plate, the top plate, the third splicing plate, and the fourth splicing plate; the two ends of the thermal serpentine fluid flow channel are respectively connected to the first hydraulic quick-change female head and the second hydraulic quick-change female head. The cold serpentine fluid flow channel is sequentially arranged on one side of the assembled shear box assembly of the second splicing plate, the first splicing plate, the top plate, the third splicing plate, and the fourth splicing plate; the two ends of the cold serpentine fluid flow channel are respectively connected to the third hydraulic quick-change female head and the fourth hydraulic quick-change female head. A temperature display is provided on the side of the top plate away from the assembled shear box assembly; The first hydraulic quick-connect female connector is connected to the first hydraulic quick-connect male connector, the second hydraulic quick-connect female connector is connected to the second hydraulic quick-connect male connector, the third hydraulic quick-connect female connector is connected to the third hydraulic quick-connect male connector, and the fourth hydraulic quick-connect female connector is connected to the fourth hydraulic quick-connect male connector. The locking mechanism is located on the side wall of the second and fourth splicing plates away from the side where the spliced ​​shear box assembly is located; The device frame is detachably connected to the second and fourth splicing plates via a locking mechanism; The device frame is fixedly installed on the test bench.

[0009] Furthermore, the assembled shear box assembly includes an upper shear box, a lower shear box, a flexible metal sealing assembly, and a central air bladder; The bottom of the upper shear box is provided with a first groove for accommodating the rock sample; the top of the lower shear box is provided with a second groove for accommodating the rock sample. When the bottom surface of the upper shear box abuts against the top surface of the lower shear box, the first groove and the second groove together form a receiving cavity for accommodating the rock sample. The top of the upper shear box is connected to a stiffness servo loading system to apply a normal load in the vertically downward direction to the rock sample. The stiffness servo loading system is connected to the first side wall of the upper shear box and the second side wall of the lower shear box respectively, so as to apply shear loads perpendicular to the normal load in opposite directions to the rock sample respectively. An air bladder that contacts the rock sample is provided between the rock sample and the side wall of the upper shear box perpendicular to the shear load, and between the rock sample and the side wall of the lower shear box perpendicular to the shear load. A first annular pre-reserved groove for accommodating the air bladder is provided on the side wall of the rock sample and the upper shear box perpendicular to the shear load; a second annular pre-reserved groove for accommodating the air bladder is provided on the side wall of the rock sample and the lower shear box perpendicular to the shear load. The upper shear box and the lower shear box are respectively provided with a seepage outlet and a seepage inlet; both the seepage outlet and the seepage inlet are connected to the seepage and dynamic sealing system; The flexible metal sealing component is disposed between the rock sample and the air bladder. After the air bladder is inflated, the flexible metal sealing component can be in close contact with the rock sample.

[0010] Furthermore, the stiffness servo loading system includes a normal loading unit, a first shear loading unit, and a second shear loading unit; The normal loading unit is connected to the top of the upper shear box and is used to apply a normal load in the vertical direction downward. The first shear loading unit is connected to the first sidewall of the upper shear box and is used to apply a horizontal shear load. The second shear loading unit is connected to the second side wall of the lower shear box and is used to apply a horizontal shear load. The first shear loading unit and the second shear loading unit are disposed on both sides of the assembled shear box assembly.

[0011] Furthermore, the seepage and dynamic sealing system includes a precision air pressure controller, a pressure-resistant air pipe, a high-pressure seepage pump, a water storage tank, a first high-pressure pipeline, a second high-pressure pipeline, and a return pipeline; The outer wall of the precision pneumatic controller is equipped with a pneumatic pressure display; it is connected to the air bladder of the assembled shear box assembly via a pressure-resistant air pipe. The outer wall of the water storage tank is provided with a high-pressure water outlet, a return water inlet and a capacity display; the high-pressure water outlet is connected to one end of the first high-pressure pipeline and the return water inlet is connected to one end of the return pipeline. The high-pressure seepage pump is equipped with an inlet and an outlet; the inlet is connected to the other end of the first high-pressure pipeline, and the outlet is connected to one end of the second high-pressure pipeline. The other end of the second high-pressure pipeline is connected to the seepage inlet; The other end of the return pipeline is connected to the seepage outlet; Both the precision pneumatic controller and the high-pressure seepage pump are connected to the intelligent synchronous control system.

[0012] A method for three-field coupled rock shear rheology testing over an ultrawide temperature range includes: S1. Place the rock sample in the lower shear box and arrange a flexible metal sealing assembly between the rock sample and the air bladder; combine the upper and lower shear boxes to form a combined shear box assembly. S2. Place the assembled shear box assembly inside the quick-connect fluid temperature control jacket, so that the outer wall of the assembled shear box assembly is in close contact with the inner wall of the quick-connect fluid temperature control jacket. S3. The air bladder in the assembled shear box assembly is inflated by the seepage and dynamic sealing system, so that the air bladder expands and the flexible metal sealing component is tightly attached to the surface of the rock sample, forming a seepage channel in the annular reserved groove. S4. The temperature control medium is pumped into the hot or cold serpentine fluid channel of the quick-connect fluid temperature control jacket through an external temperature control unit to apply a temperature field to the rock sample. S5. By using a seepage and dynamic sealing system, seepage liquid is injected into the seepage channel to establish a seepage field with a constant seepage velocity; S6. Apply normal and shear loads to the rock sample simultaneously or in stages using a stiffness servo loading system to conduct compression or shear tests. S7. Through the preset coupling test mode in the intelligent synchronous control system, at least two steps from S4 to S6 are executed synchronously or in a predetermined sequence to achieve multi-field coupling test; at the same time, test data from the external temperature control unit, seepage and dynamic sealing system and stiffness servo loading system are collected to analyze the changes of rock under multi-field coupling.

[0013] Beneficial effects: The present invention provides an ultra-wide temperature range three-field coupled rock shear rheology test device and method. By coupling the temperature field (ultra-wide temperature range), stress field (normal and shear load), and seepage field (water pressure), it can highly reproduce the real multi-field coupled environment of rocks in deep geology, geothermal development, nuclear waste disposal, and energy storage projects, which greatly enhances the engineering representativeness and scientific value of the test. Relying on an external temperature control unit and a quick-connect fluid temperature control jacket, it can achieve precise and stable control over an ultra-wide temperature range from extremely low to high temperatures, meeting the research needs of rock mechanical behavior under extreme temperature conditions, from permafrost in cold regions to deep high-temperature rock masses. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the three-field coupled rock shear rheology testing device of the present invention; Figure 2 This is a schematic diagram of the external temperature control unit of the present invention; Figure 3 This is a schematic diagram of the quick-connect fluid temperature control jacket of the present invention; Figure 4 This is a schematic diagram of the assembled shear box assembly of the present invention; Figure 5 This is a schematic diagram of the stiffness servo loading system of the present invention; Figure 6 This is a schematic diagram of the seepage and dynamic sealing system of the present invention; Figure 7 This is a schematic diagram of the three-field coupled rock shear rheology test method of the present invention.

[0016] In the diagram: 1. Assembled shear box assembly; 101. Upper shear box; 102. Lower shear box; 103. First groove; 104. Second groove; 105. Flexible metal sealing assembly; 106. Middle air bladder; 107. Seepage inlet; 108. Seepage outlet; 109. First annular reserved groove; 110. Second annular reserved groove; 111. First side wall; 112. Second side wall; 2. Quick-connect fluid temperature control jacket; 201. Surrounding shell; 202. Hot serpentine fluid flow channel; 203. Cold serpentine fluid flow channel; 204. Locking mechanism; 205. Device frame; 20 6. Temperature display; 207. First hydraulic quick-connect female connector; 208. Second hydraulic quick-connect female connector; 209. Third hydraulic quick-connect female connector; 210. Fourth hydraulic quick-connect female connector; 2011. First splicing plate; 2012. Second splicing plate; 2013. Third splicing plate; 2014. Fourth splicing plate; 2015. Top plate; 3. Stiffness servo loading system; 301. Normal loading unit; 302. First shear loading unit; 303. Second shear loading unit; 4. Seepage and dynamic sealing system; 401. Precision air pressure controller; 402. Durability... 403. Compressed air pipe; 404. High-pressure seepage pump; 405. Water storage tank; 406. First high-pressure pipeline; 407. Second high-pressure pipeline; 408. Return pipeline; 409. Capacity display; 410. Air pressure display; 411. High-pressure water outlet; 412. Return water inlet; 413. Inlet; 414. Outlet; 5. Intelligent synchronous control system; 6. External temperature control unit; 601. High-temperature silicone oil storage tank; 602. Immersion electric heater; 603. High-temperature circulating pump; 604. Heating controller; 605. High-temperature circulating oil supply pipeline; 606. High-temperature circulating oil return pipeline; 6 607. High-temperature silicone oil outlet; 608. High-temperature silicone oil inlet; 609. High-temperature circulating pump interface; 610. Ethylene glycol solution storage tank; 611. Compression refrigeration system; 612. Low-temperature circulating pump; 613. Refrigeration controller; 614. Low-temperature circulating water supply pipeline; 615. Low-temperature circulating water return pipeline; 616. Ethylene glycol solution outlet; 617. Ethylene glycol solution inlet; 618. Low-temperature circulating pump interface; 619. First hydraulic quick-connect male connector; 620. Second hydraulic quick-connect male connector; 621. Third hydraulic quick-connect male connector; 622. Fourth hydraulic quick-connect male connector. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] This embodiment provides an ultra-wide temperature range three-field coupled rock shear rheology testing device, such as... Figures 1 to 6 As shown, it includes: a modular shear box assembly 1, a quick-connect fluid temperature control jacket 2, a stiffness servo loading system 3, a seepage and dynamic sealing system 4, an intelligent synchronous control system 5, and an external temperature control unit 6. The assembled shear box assembly 1 contains a rock sample; The assembled shear box assembly 1 is connected to the quick-connect fluid temperature control jacket 2; The external temperature control unit 6 is connected to the quick-connect fluid temperature control jacket 2 and is used to provide the rock sample with a temperature within a set temperature range through the quick-connect fluid temperature control jacket 2. The stiffness servo loading system 3 is connected to the assembled shear box assembly 1 and is used to apply normal load and shear load to the rock sample set inside the assembled shear box assembly 1. The seepage and dynamic sealing system 4 is connected to the assembled shear box assembly 1 and is used to apply seepage water pressure and air pressure to the rock sample. The intelligent synchronous control system 5 is connected to the external temperature control unit 6, the stiffness servo loading system 3, and the seepage and dynamic sealing system 4 via signals.

[0019] Preferably, the external temperature control unit 6 includes a high-temperature silicone oil storage tank 601, a high-temperature circulating pump 603, a high-temperature circulating oil supply pipeline 605, a high-temperature circulating oil return pipeline 606, an ethylene glycol solution storage tank 610, a low-temperature circulating pump 612, a low-temperature circulating water supply pipeline 614, and a low-temperature circulating water return pipeline 615. The high-temperature silicone oil storage tank 601 is equipped with an immersion electric heater 602 inside, and a heating controller 604, a high-temperature silicone oil outlet 607, a high-temperature silicone oil inlet 608 and a high-temperature circulating pump interface 609 on the outer wall. The heating controller 604 is communicatively connected to the intelligent synchronous control system 5 and the immersion electric heater 602, respectively. The high-temperature silicone oil storage tank 601 is connected to one end of the high-temperature circulating oil supply pipeline 605 via the high-temperature silicone oil outlet 607, to one end of the high-temperature circulating oil return pipeline 606 via the high-temperature silicone oil inlet 608, and to the high-temperature circulating pump 603 via the high-temperature circulating pump interface 609. The other ends of the high-temperature circulating oil supply line 605 and the high-temperature circulating oil return line 606 are respectively provided with a first hydraulic quick-connect male connector 619 and a second hydraulic quick-connect male connector 620. The ethylene glycol solution storage tank 610 is equipped with a compression refrigeration system 611 inside, and a refrigeration controller 613, an ethylene glycol solution outlet 616, an ethylene glycol solution inlet 617 and a low-temperature circulating pump interface 618 on its outer wall. The refrigeration controller 613 is communicatively connected to the intelligent synchronous control system 5 and the compression refrigeration system 611 respectively; The ethylene glycol solution storage tank 610 is connected to one end of the low-temperature circulating water supply pipeline 614 via the ethylene glycol solution outlet 616, to one end of the low-temperature circulating water return pipeline 615 via the ethylene glycol solution inlet 617, and to the low-temperature circulating pump 612 via the low-temperature circulating pump interface 618. The other ends of the low-temperature circulating water supply pipeline 614 and the low-temperature circulating water return pipeline 615 are respectively provided with a third hydraulic quick-connect male connector 621 and a fourth hydraulic quick-connect male connector 622. The first hydraulic quick-connect male connector 619, the second hydraulic quick-connect male connector 620, the third hydraulic quick-connect male connector 621 and the fourth hydraulic quick-connect male connector 622 are connected to the quick-connect fluid temperature control jacket 2.

[0020] In this embodiment, the high-temperature silicone oil storage tank 601 has a capacity of 50L and is made of 304 stainless steel; the total power of the immersion electric heater 602 is 9kW; and the maximum flow rate of the high-temperature circulating pump 603 is 15L / min. The capacity of the ethylene glycol solution storage tank 610 is 40L.

[0021] Preferably, the high-temperature silicone oil storage tank 601 is used to store silicone oil, and the immersion electric heater 602 is controlled by the heating controller 604 to heat the silicone oil, so that the temperature of the silicone oil can be adjusted between room temperature and 300°C. The ethylene glycol solution storage tank 610 is used to store ethylene glycol aqueous solution. The refrigeration system 611 is controlled by the refrigeration controller 613 to refrigerate the ethylene glycol aqueous solution, so that the temperature of the ethylene glycol aqueous solution can be adjusted between room temperature and -40°C.

[0022] In this embodiment, the high-temperature silicone oil is a phenyl-modified silicone oil, which can withstand high temperatures ranging from 250°C to 350°C. The concentration of the ethylene glycol solution is 60%, and when mixed with water, the freezing point can be as low as -50°C.

[0023] Preferably, the quick-connect fluid temperature control jacket 2 includes a surrounding housing 201, a hot serpentine fluid channel 202, a cold serpentine fluid channel 203, a locking mechanism 204, and a device frame 205; The surrounding housing 201 includes a first side plate, a second side plate, and a top plate 2015; The first side panel includes a first splicing plate 2011 and a second splicing plate 2012; The second side panel includes a third splicing panel 2013 and a fourth splicing panel 2014; In this embodiment, the first side panel is formed by splicing a first splicing plate 2011 and a second splicing plate 2012; the second side panel is formed by splicing a third splicing plate 2013 and a fourth splicing plate 2014. The top plate 2015 is fixed perpendicularly to the top of the first splicing plate 2011 and the top of the third splicing plate 2013, respectively; the second splicing plate 2012 and the fourth splicing plate 2014 are disposed on one side of the top plate 2015. The thermal serpentine fluid flow channel 202 is sequentially arranged on one side of the assembled shear box assembly 1, consisting of the second splicing plate 2012, the first splicing plate 2011, the top plate 2015, the third splicing plate 2013, and the fourth splicing plate 2014; the two ends of the thermal serpentine fluid flow channel 202 are respectively connected to the first hydraulic quick-connect female head 207 and the second hydraulic quick-connect female head 208. The cold serpentine fluid flow channel 203 is sequentially arranged on one side of the assembled shear box assembly 1, consisting of the second splicing plate 2012, the first splicing plate 2011, the top plate 2015, the third splicing plate 2013, and the fourth splicing plate 2014; the two ends of the cold serpentine fluid flow channel 203 are respectively connected to the third hydraulic quick-change female connector 209 and the fourth hydraulic quick-change female connector 210; In this embodiment, the first hydraulic quick-connect female head 207 and the third hydraulic quick-connect female head 209 are disposed on the outer sidewall of the second splicing plate 2012; the second hydraulic quick-connect female head 208 and the fourth hydraulic quick-connect female head 210 are disposed on the outer sidewall of the fourth splicing plate 2014. A temperature display 206 is provided on the side of the top plate 2015 away from the side where the assembled shear box assembly 1 is located; The first hydraulic quick-connect female connector 207 is connected to the first hydraulic quick-connect male connector 619, the second hydraulic quick-connect female connector 208 is connected to the second hydraulic quick-connect male connector 620, the third hydraulic quick-connect female connector 209 is connected to the third hydraulic quick-connect male connector 621, and the fourth hydraulic quick-connect female connector 210 is connected to the fourth hydraulic quick-connect male connector 622. The locking mechanism 204 is disposed on the side wall of the second splicing plate 2012 and the fourth splicing plate 2014 away from the side where the spliced ​​shear box assembly 1 is disposed; The device frame 205 is detachably connected to the second splicing plate 2012 and the fourth splicing plate 2014 via a locking mechanism 204; The device frame 205 is fixedly installed on the test bench.

[0024] Specifically, the surrounding housing 201 is made of high thermal conductivity aluminum alloy by milling, and its inner wall matches the external shape of the assembled shear box assembly 1; The hot serpentine fluid flow channel 202 and the cold serpentine fluid flow channel 203 are integrally molded components; The locking mechanism 204 also has 6 pneumatic cylinders for uniformly pressing the surrounding housing 201.

[0025] Preferably, the assembled shear box assembly 1 includes an upper shear box 101, a lower shear box 102, a flexible metal sealing assembly 105, and a central air bladder 106; The bottom of the upper shear box 101 is provided with a first groove 103 for accommodating a rock sample; the top of the lower shear box 102 is provided with a second groove 104 for accommodating a rock sample. When the bottom surface of the upper shear box 101 abuts against the top surface of the lower shear box 102, the first groove 103 and the second groove 104 together form a receiving cavity for accommodating the rock sample. The top of the upper shear box 101 is connected to the stiffness servo loading system 3 to apply a normal load in the vertically downward direction to the rock sample. The stiffness servo loading system 3 is connected to the first side wall 111 of the upper shear box 101 and the second side wall 112 of the lower shear box 102, respectively, so as to apply shear loads perpendicular to the normal load in opposite directions to the rock sample. An air bladder 106 is provided between the rock sample and the side wall of the upper shear box 101 perpendicular to the shear load, and between the rock sample and the side wall of the lower shear box 102 perpendicular to the shear load, which is in contact with the rock sample. A first annular reserved groove 109 for accommodating the air bladder 106 is provided on the side wall of the rock sample and the upper shear box 101 perpendicular to the shear load; a second annular reserved groove 110 for accommodating the air bladder 106 is provided on the side wall of the rock sample and the lower shear box 102 perpendicular to the shear load. The upper shear box 101 and the lower shear box 102 are respectively provided with a seepage outlet 108 and a seepage inlet 107; both the seepage outlet 108 and the seepage inlet 107 are connected to the seepage and dynamic sealing system 4. The flexible metal sealing component 105 is disposed between the rock sample and the air bladder 106. After the air bladder 106 is inflated, the flexible metal sealing component 105 can be in close contact with the rock sample.

[0026] In this embodiment, the upper shear box 101 and the lower shear box 102 are made of high-strength precipitation-hardening stainless steel (such as 17-4PH); the contact surfaces of the upper and lower parts are ground and the flatness is better than 0.02mm. The assembled sealed cuboid chamber can hold a standard rock sample with dimensions of 200mm×100mm×100mm. The flexible metal sealing component 105 uses annealed copper foil with a thickness of 0.2 mm, wherein a microscopic pyramid-shaped bump array with a height of about 50 μm is formed on the contact surface with the sample through photolithography etching process. The air bladder 106 is made of a composite of fluororubber and aramid fiber reinforcement layer, and is fixed in the first annular pre-reserved groove 109 and the second annular pre-reserved groove 110 by high temperature resistant epoxy adhesive.

[0027] Preferably, the stiffness servo loading system 3 includes a normal loading unit 301, a first shear loading unit 302, and a second shear loading unit 303; The normal loading unit 301 is connected to the top of the upper shear box 101 and is used to apply a normal load in the vertical direction downward. The first shear loading unit 302 is connected to the first side wall 111 of the upper shear box 101 and is used to apply a horizontal shear load. The second shear loading unit 303 is connected to the second side wall 112 of the lower shear box 102 and is used to apply a horizontal shear load. The first shear loading unit 302 and the second shear loading unit 303 are disposed on both sides of the assembled shear box assembly 1.

[0028] In this embodiment, the normal loading unit 301 adopts a servo electric cylinder with a maximum thrust of 500kN, and is detachably connected to the top of the upper shear box 101 through an auto-aligning ball joint. The first shearing loading unit 302 and the second shearing loading unit 303 are servo electric cylinders with a maximum thrust of 300kN and a stroke of ±50mm; they are detachably connected to the sides of the upper shear box 101 and the lower shear box 102 respectively via universal joints. The normal loading unit 301, the first shear loading unit 302, and the second shear loading unit 303 all integrate a high-precision spoke-type force sensor (accuracy 0.5% FS) and a grating ruler displacement sensor (resolution 1μm); The stiffness servo loading system 3 is made of high-rigidity cast iron, and the axial stiffness of the system is not less than 5 GN / m.

[0029] Preferably, the seepage and dynamic sealing system 4 includes a precision air pressure controller 401, a pressure-resistant air pipe 402, a high-pressure seepage pump 403, a water storage tank 404, a first high-pressure pipeline 405, a second high-pressure pipeline 406, and a return pipeline 407. The outer wall of the precision air pressure controller 401 is provided with an air pressure display 409; it is connected to the air bladder 106 of the assembled shear box assembly 1 through a pressure-resistant air pipe 402. The outer wall of the water storage tank 404 is provided with a high-pressure water outlet 410, a return water inlet 411 and a capacity display 408; the high-pressure water outlet 410 is connected to one end of the first high-pressure pipeline 405, and the return water inlet 411 is connected to one end of the return pipeline 407. The high-pressure seepage pump 403 is provided with an inlet 412 and an outlet 413; it is connected to the other end of the first high-pressure pipeline 405 through the inlet 412 and to one end of the second high-pressure pipeline 406 through the outlet 413. The other end of the second high-pressure pipeline 406 is connected to the seepage inlet 107; The other end of the return pipe 407 is connected to the seepage outlet 108; Both the precision air pressure controller 401 and the high-pressure seepage pump 403 are communicatively connected to the intelligent synchronous control system 5.

[0030] In this embodiment, the precision pneumatic controller 401 is an electro-proportional valve with an output pressure range of 0-2.5MPa and a control accuracy of ±0.5% FS; The high-pressure percolation pump 403 is a dual-plunger parallel constant flow / constant pressure pump with a maximum output pressure of 30MPa and a flow rate range of 0.01-10mL / min.

[0031] In this embodiment, the intelligent synchronous control system 5 is built based on an industrial control computer and a programmable logic controller (PLC); wherein, the industrial control computer is equipped with dedicated software and has a graphical test sequence editing interface, allowing users to programmatically define complex time-series coupling paths with multiple parameters such as temperature, normal stress, shear stress / displacement, airbag pressure, and seepage pressure; The intelligent synchronous control system 5 is triggered by a unified hardware clock and synchronously collects data from all sensor channels at a sampling rate of not less than 10Hz.

[0032] The second embodiment provides a method for ultra-wide temperature range three-field coupled rock shear rheology testing, such as... Figure 7 As shown, it includes: S1. Place the rock sample in the lower shear box and arrange a flexible metal sealing assembly between the rock sample and the air bladder; combine the upper and lower shear boxes to form a combined shear box assembly. Specifically, select a rock sample with dimensions of 200mm×100mm×100mm and ensure that the parallelism error of the opposing surfaces is less than 0.05mm; Clean the surface of the rock sample with alcohol and dry it; attach the two flexible metal sealing components tightly to the front and back sides of the sample, with the copper foil protrusions in contact with the rock sample. S2. Place the assembled shear box assembly inside the quick-connect fluid temperature control jacket, so that the outer wall of the assembled shear box assembly is in close contact with the inner wall of the quick-connect fluid temperature control jacket. Specifically, the male connectors of the first to fourth hydraulic quick-connect couplings in the external temperature control unit are connected to the female connectors of the first to fourth hydraulic quick-connect couplings in the quick-connect fluid temperature control jacket; The high-pressure seepage pump is connected to the water storage tank through a first high-pressure pipeline and to the seepage inlet through a second high-pressure pipeline; at the same time, the water storage tank is connected to the seepage outlet through a return pipeline to form a seepage circulation loop. S3. The air bladder in the assembled shear box assembly is inflated by the seepage and dynamic sealing system, so that the air bladder expands and the flexible metal sealing component is tightly attached to the surface of the rock sample, forming a seepage channel in the annular reserved groove. In this embodiment, a sealing test is performed on the air bladder and the seepage channel, specifically as follows: S31. Pressurize the medium-pressure airbag to 0.5 MPa in stages using a precision air pressure controller and maintain the pressure for 180 seconds; S32. Monitor the pressure decay rate of the air pressure in the airbag, wherein the qualified condition for the pressure decay rate is less than 0.01 MPa / 3min; S33. Deionized water is pumped into the percolation circulation loop at a low flow rate using a high-pressure percolation pump, and the pressure is slowly increased to 1.0 MPa and maintained for 300 seconds. S34. Monitor the pressure decay rate of water pressure in the seepage circulation loop. The qualified condition for the pressure decay rate is that the pressure decay rate is less than 0.02 MPa / min. S35. If the pressure decay rate of air pressure and the pressure decay rate of water pressure meet the qualified conditions, the seal is deemed qualified, and the pressure of the air bladder is automatically increased to the preset working pressure (e.g., 0.8 MPa), and the seepage pressure is adjusted to the initial value; otherwise, the seal is deemed unqualified, and the location of air or water leakage is checked. S4. The temperature control medium is pumped into the hot or cold serpentine fluid channel of the quick-connect fluid temperature control jacket through an external temperature control unit to apply a temperature field to the rock sample. S5. By using a seepage and dynamic sealing system, seepage liquid is injected into the seepage channel to establish a seepage field with a constant seepage velocity; S6. Apply normal and shear loads to the rock sample simultaneously or in stages using a stiffness servo loading system to conduct compression or shear tests. S7. Through the preset coupling test mode in the intelligent synchronous control system, at least two steps from S4 to S6 are executed synchronously or in a predetermined sequence to achieve multi-field coupling test; at the same time, test data from the external temperature control unit, seepage and dynamic sealing system and stiffness servo loading system are collected to analyze the changes of rock under multi-field coupling.

[0033] In this embodiment, four types of multi-field coupling tests are set, including: temperature-stress coupling test, seepage-stress coupling test, temperature-seepage-stress full coupling test, and long-term creep-temperature / seepage cycle coupling test. The long-term creep-temperature / seepage cycle coupling test involves applying long-term stable normal and shear loads to conduct creep tests. During the creep process, which can last for weeks or even months, multiple temperature cycles and seepage cycles of a limited number of cycles are programmed and embedded to simulate the long-term mechanical behavior of rocks in cold-region freeze-thaw cycles or deep hot-water cycles.

[0034] The present invention has the following beneficial effects: This invention provides an ultra-wide temperature range three-field coupled rock shear rheology test device and method. By coupling the temperature field (ultra-wide temperature range), stress field (normal and shear load), and seepage field (water pressure), it can highly reproduce the real multi-field coupled environment of rocks in deep geology, geothermal development, nuclear waste disposal, and energy storage projects, greatly enhancing the engineering representativeness and scientific value of the test. Relying on an external temperature control unit and a quick-connect fluid temperature control jacket, it can achieve precise and stable control over an ultra-wide temperature range from extremely low to high temperatures, meeting the research needs of rock mechanical behavior under extreme temperature conditions, from permafrost in cold regions to deep high-temperature rock masses.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-field coupled rock shear rheology testing device with an ultra-wide temperature range, characterized in that, include: The assembly includes a modular shear box assembly (1), a quick-connect fluid temperature control jacket (2), a stiffness servo loading system (3), a seepage and dynamic sealing system (4), an intelligent synchronous control system (5), and an external temperature control unit (6). The assembled shear box assembly (1) contains a rock sample; The assembled shear box assembly (1) is connected to the quick-connect fluid temperature control jacket (2); The external temperature control unit (6) is connected to the quick-connect fluid temperature control jacket (2) and is used to provide the rock sample with a temperature within a set temperature range through the quick-connect fluid temperature control jacket (2); The stiffness servo loading system (3) is connected to the assembled shear box assembly (1) and is used to apply normal load and shear load to the rock sample set inside the assembled shear box assembly (1); The seepage and dynamic sealing system (4) is connected to the assembled shear box assembly (1) and is used to apply seepage water pressure and air pressure to the rock sample; The intelligent synchronous control system (5) is connected to the external temperature control unit (6), the stiffness servo loading system (3), and the seepage and dynamic sealing system (4) via signal connection.

2. The ultra-wide temperature range three-field coupled rock shear rheology testing device according to claim 1, characterized in that, The external temperature control unit (6) includes a high-temperature silicone oil storage tank (601), a high-temperature circulating pump (603), a high-temperature circulating oil supply pipeline (605), a high-temperature circulating oil return pipeline (606), an ethylene glycol solution storage tank (610), a low-temperature circulating pump (612), a low-temperature circulating water supply pipeline (614), and a low-temperature circulating water return pipeline (615). The high-temperature silicone oil storage tank (601) is equipped with an immersion electric heater (602) inside and a heating controller (604), a high-temperature silicone oil outlet (607), a high-temperature silicone oil inlet (608), and a high-temperature circulating pump interface (609) on its outer wall. The heating controller (604) is communicatively connected to the intelligent synchronous control system (5) and the immersion electric heater (602); The high-temperature silicone oil storage tank (601) is connected to one end of the high-temperature circulating oil supply pipeline (605) through the high-temperature silicone oil outlet (607), to one end of the high-temperature circulating oil return pipeline (606) through the high-temperature silicone oil inlet (608), and to the high-temperature circulating pump (603) through the high-temperature circulating pump interface (609). The other ends of the high-temperature circulating oil supply pipeline (605) and the high-temperature circulating oil return pipeline (606) are respectively provided with a first hydraulic quick-connect male connector (619) and a second hydraulic quick-connect male connector (620). The ethylene glycol solution storage tank (610) is equipped with a compression refrigeration system (611) inside, and a refrigeration controller (613), an ethylene glycol solution outlet (616), an ethylene glycol solution inlet (617), and a low-temperature circulating pump interface (618) on its outer wall. The refrigeration controller (613) is communicatively connected to the intelligent synchronous control system (5) and the compression refrigeration system (611); The ethylene glycol solution storage tank (610) is connected to one end of the low-temperature circulating water supply pipeline (614) through the ethylene glycol solution outlet (616), to one end of the low-temperature circulating return water pipeline (615) through the ethylene glycol solution inlet (617), and to the low-temperature circulating pump (612) through the low-temperature circulating pump interface (618). The other ends of the low-temperature circulating water supply pipeline (614) and the low-temperature circulating water return pipeline (615) are respectively provided with a third hydraulic quick-connect male connector (621) and a fourth hydraulic quick-connect male connector (622). The first hydraulic quick-connect male connector (619), the second hydraulic quick-connect male connector (620), the third hydraulic quick-connect male connector (621) and the fourth hydraulic quick-connect male connector (622) are connected to the quick-connect fluid temperature control jacket (2).

3. The ultra-wide temperature range three-field coupled rock shear rheology testing device according to claim 2, characterized in that, The high-temperature silicone oil storage tank (601) is used to store silicone oil. The immersion electric heater (602) is controlled by the heating controller (604) to heat the silicone oil, so that the temperature of the silicone oil can be adjusted between room temperature and 300°C. The ethylene glycol solution storage tank (610) is used to store ethylene glycol aqueous solution. The refrigeration system (611) is controlled by the refrigeration controller (613) to refrigerate the ethylene glycol aqueous solution, so that the temperature of the ethylene glycol aqueous solution is adjusted between room temperature and -40°C.

4. The ultra-wide temperature range three-field coupled rock shear rheology testing device according to claim 2, characterized in that, The quick-connect fluid temperature control jacket (2) includes a surrounding housing (201), a hot serpentine fluid channel (202), a cold serpentine fluid channel (203), a locking mechanism (204), and a device frame (205). The surrounding housing (201) includes a first side plate, a second side plate, and a top plate (2015). The first side panel includes a first splicing plate (2011) and a second splicing plate (2012); The second side panel includes a third splicing panel (2013) and a fourth splicing panel (2014). The top plate (2015) is vertically fixed at both ends to the top of the first splicing plate (2011) and the top of the third splicing plate (2013), respectively; the second splicing plate (2012) and the fourth splicing plate (2014) are disposed on one side of the top plate (2015); The thermal serpentine fluid flow channel (202) is sequentially arranged on one side of the splicing shear box assembly (1) of the second splicing plate (2012), the first splicing plate (2011), the top plate (2015), the third splicing plate (2013), and the fourth splicing plate (2014); the two ends of the thermal serpentine fluid flow channel (202) are respectively connected to the first hydraulic quick-connect female head (207) and the second hydraulic quick-connect female head (208); The cold serpentine fluid flow channel (203) is sequentially arranged on one side of the splicing shear box assembly (1) of the second splicing plate (2012), the first splicing plate (2011), the top plate (2015), the third splicing plate (2013), and the fourth splicing plate (2014); the two ends of the cold serpentine fluid flow channel (203) are respectively connected to the third hydraulic quick-change female head (209) and the fourth hydraulic quick-change female head (210); A temperature display (206) is provided on the side of the top plate (2015) away from the assembled shear box assembly (1). The first hydraulic quick-connect female connector (207) is connected to the first hydraulic quick-connect male connector (619), the second hydraulic quick-connect female connector (208) is connected to the second hydraulic quick-connect male connector (620), the third hydraulic quick-connect female connector (209) is connected to the third hydraulic quick-connect male connector (621), and the fourth hydraulic quick-connect female connector (210) is connected to the fourth hydraulic quick-connect male connector (622). The locking mechanism (204) is disposed on the side wall of the second splicing plate (2012) and the fourth splicing plate (2014) away from the splicing shear box assembly (1); The device frame (205) is detachably connected to the second splicing plate (2012) and the fourth splicing plate (2014) via a locking mechanism (204); The device frame (205) is fixedly installed on the test bench.

5. The ultra-wide temperature range three-field coupled rock shear rheology testing device according to claim 4, characterized in that, The assembled shear box assembly (1) includes an upper shear box (101), a lower shear box (102), a flexible metal sealing assembly (105), and a central air bladder (106). The bottom of the upper shear box (101) is provided with a first groove (103) for accommodating the rock sample; the top of the lower shear box (102) is provided with a second groove (104) for accommodating the rock sample. When the bottom surface of the upper shear box (101) abuts against the top surface of the lower shear box (102), the first groove (103) and the second groove (104) together form a receiving cavity for accommodating the rock sample. The top of the upper shear box (101) is connected to the stiffness servo loading system (3) to apply a normal load in the vertically downward direction to the rock sample; The stiffness servo loading system (3) is connected to the first sidewall (111) of the upper shear box (101) and the second sidewall (112) of the lower shear box (102) respectively, so as to apply shear loads perpendicular to the normal load in opposite directions to the rock sample respectively. An air bladder (106) that contacts the rock sample is provided between the rock sample and the side wall of the upper shear box (101) perpendicular to the shear load, and between the rock sample and the side wall of the lower shear box (102) perpendicular to the shear load. A first annular groove (109) for accommodating the air bladder (106) is provided on the side wall of the rock sample and the upper shear box (101) perpendicular to the shear load; a second annular groove (110) for accommodating the air bladder (106) is provided on the side wall of the rock sample and the lower shear box (102) perpendicular to the shear load. The upper shear box (101) and the lower shear box (102) are respectively provided with a seepage outlet (108) and a seepage inlet (107); the seepage outlet (108) and the seepage inlet (107) are both connected to the seepage and dynamic sealing system (4); The flexible metal sealing component (105) is disposed between the rock sample and the air bladder (106). After the air bladder (106) is inflated, the flexible metal sealing component (105) can be in close contact with the rock sample.

6. The ultra-wide temperature range three-field coupled rock shear rheology testing device according to claim 5, characterized in that, The stiffness servo loading system (3) includes a normal loading unit (301), a first shear loading unit (302), and a second shear loading unit (303). The normal loading unit (301) is connected to the top of the upper shear box (101) and is used to apply a normal load in the vertical direction downward. The first shear loading unit (302) is connected to the first sidewall (111) of the upper shear box (101) and is used to apply a horizontal shear load. The second shear loading unit (303) is connected to the second sidewall (112) of the lower shear box (102) and is used to apply a horizontal shear load; The first shear loading unit (302) and the second shear loading unit (303) are disposed on both sides of the assembled shear box assembly (1).

7. The ultra-wide temperature range three-field coupled rock shear rheology testing device according to claim 5, characterized in that, The seepage and dynamic sealing system (4) includes a precision air pressure controller (401), a pressure-resistant air pipe (402), a high-pressure seepage pump (403), a water storage tank (404), a first high-pressure pipeline (405), a second high-pressure pipeline (406), and a return pipeline (407). The outer wall of the precision air pressure controller (401) is provided with an air pressure display (409); it is connected to the air bladder (106) of the assembled shear box assembly (1) through a pressure-resistant air pipe (402); The outer wall of the water storage tank (404) is provided with a high-pressure water outlet (410), a return water inlet (411) and a capacity display (408); the high-pressure water outlet (410) is connected to one end of the first high-pressure pipeline (405), and the return water inlet (411) is connected to one end of the return pipeline (407); The high-pressure seepage pump (403) is provided with an inlet (412) and an outlet (413); it is connected to the other end of the first high-pressure pipeline (405) through the inlet (412) and to one end of the second high-pressure pipeline (406) through the outlet (413); The other end of the second high-pressure pipeline (406) is connected to the seepage inlet (107); The other end of the return pipe (407) is connected to the seepage outlet (108); The precision air pressure controller (401) and the high-pressure seepage pump (403) are both connected to the intelligent synchronous control system (5).

8. A test method based on the ultra-wide temperature range three-field coupled rock shear rheology test apparatus according to any one of claims 1 to 7, characterized in that, include: S1. Place the rock sample in the lower shear box and arrange a flexible metal sealing assembly between the rock sample and the air bladder; combine the upper and lower shear boxes to form a combined shear box assembly. S2. Place the assembled shear box assembly inside the quick-connect fluid temperature control jacket, so that the outer wall of the assembled shear box assembly is in close contact with the inner wall of the quick-connect fluid temperature control jacket. S3. The air bladder in the assembled shear box assembly is inflated by the seepage and dynamic sealing system, so that the air bladder expands and the flexible metal sealing component is tightly attached to the surface of the rock sample, forming a seepage channel in the annular reserved groove. S4. The temperature control medium is pumped into the hot or cold serpentine fluid channel of the quick-connect fluid temperature control jacket through an external temperature control unit to apply a temperature field to the rock sample. S5. By using a seepage and dynamic sealing system, seepage liquid is injected into the seepage channel to establish a seepage field with a constant seepage velocity; S6. Apply normal and shear loads to the rock sample simultaneously or in stages using a stiffness servo loading system to conduct compression or shear tests. S7. Through the preset coupling test mode in the intelligent synchronous control system, at least two steps from S4 to S6 are executed synchronously or in a predetermined sequence to achieve multi-field coupling test; at the same time, test data from the external temperature control unit, seepage and dynamic sealing system and stiffness servo loading system are collected to analyze the changes of rock under multi-field coupling.

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