1. A rock soil moisture, heat, force couple crack analogue means that uses, wherein including proof box, environmental temperature and humidity control system and measurement system;

the test box is used for placing a rock-soil sample and simulating the humidity, the temperature and the illumination environment of the rock-soil sample;

the environment temperature and humidity control system is used for controlling the humidity and the temperature;

the rock-soil sample is wrapped with rubber membranes (10) with different layers along with the change of the height of the sample, and the rubber membranes are used for simulating the confining pressure applied to the rock-soil sample;

the measuring system comprises a temperature sensor, a microwave heating device (9) and an infrared imager (7);

the temperature sensor is used for monitoring the temperature of the rock-soil sample;

the microwave heating device (9) is used for heating water in the rock-soil sample by microwaves;

and the infrared imager (7) is used for recording the form and the change of water in the rock-soil sample in the whole microwave heating process, so that the form and the change of the internal fracture of the rock-soil sample are obtained.

2. The crack simulation device for coupling moisture, heat and force of rock and soil according to claim 1, characterized in that the test box comprises an environment simulation box (3), the wall of the environment simulation box (3) adopts a heat insulation structure, a sample chamber (19) is arranged in the environment simulation box (3), the wall of the sample chamber (19) adopts a microwave insulation structure, and a rock and soil sample is placed in the sample chamber (19).

3. The rock soil moisture, heat and force coupling fracture simulation device is characterized in that an upper water seeping device (22) is mounted at the upper part of a rock soil sample, the upper water seeping device (22) comprises a cylindrical barrel, the diameter of the barrel is the same as that of the sample, a PVC water permeable membrane is arranged at the bottom of the barrel and is in contact with the top of the rock soil sample, the upper water seeping device (22) is connected with a Mariotte bottle (12) through a corresponding water conveying pipe (18) and is used for maintaining the height of water in the upper water seeping device (22), and an automatic valve is mounted on the water conveying pipe (18) connected with the upper water seeping device (22) and is used for conveying water to the upper water seeping device (22) at regular time to simulate surface water retention;

the middle part of the rock-soil sample is provided with a middle water seepage device, namely an annular water seepage device (17), the annular water seepage device (17) comprises a cylinder body with a circular cross section, the inner diameter of the cylinder body is the same as the diameter of the rock-soil sample, the inner side wall of the cylinder body is provided with a PVC permeable membrane, the annular water seepage device (17) is connected with the Ma's flask (12) through a corresponding water delivery pipe (18) and used for controlling the water seepage degree of the annular water seepage device (17), and the annular water seepage device (17) seeps water to the upper and lower directions of the sample through the PVC permeable membrane;

the device is characterized in that a lower water seeping device (23) is installed on the lower portion of the rock-soil sample, the lower water seeping device (23) comprises a cylindrical barrel, the diameter of the rock-soil sample is smaller than that of the barrel, the lower water seeping device (23) is connected with a Ma-shi bottle (12) through a corresponding water conveying pipe (18) and used for simulating the height of the water level of underground water, and the lower water seeping device (23) seeps water into the rock-soil sample through a permeable stone (8).

4. The device for simulating the cracks in rock-soil moisture, heat and force coupling action according to claim 1, characterized in that a height-adjustable and angle-adjustable spotlight (14) is installed above the sample chamber (19).

5. The rock soil moisture, heat and force coupling crack simulation device according to claim 1, wherein a heating plate (6) is installed in the environment simulation box (3), and a plurality of micro fans (5) are installed on the inner side wall of the environment simulation box (3) and used for blowing hot air to a position far away from the heating plate (6) so that the environment simulation box (3) is heated more uniformly.

6. The crack simulator for coupling moisture, heat and force of rock and soil according to claim 1, characterized in that a temperature sensor is installed in the sample chamber (19), the temperature sensor is electrically connected with a temperature controller (11) through a lead (4), the temperature controller (11) is electrically connected with the heating plate (6) and is used for controlling the heating plate (6) to be opened or closed according to the temperature measured by the temperature sensor; the temperature sensor is electrically connected with a display screen outside the environment simulation box (3) through a lead (4) and is used for reading and displaying temperature data measured by the temperature sensor.

7. The rock soil moisture, heat and force coupling fracture simulation device is characterized in that the microwave heating device (9) is installed inside the side wall of the sample chamber (19), the side wall of the sample chamber (19) where the microwave heating device (9) is installed is provided with a microwave isolation structure, microwave energy is transmitted into the sample chamber (19) to rapidly raise the temperature of water inside the rock soil sample, and the microwave heating device (9) is connected with a computer through a data collection control line.

8. The fracture simulator for coupling moisture, heat and force in rock and soil according to claim 1, wherein at least two infrared imagers (7) are provided and are respectively installed at the inner sides of two mutually perpendicular side walls of the sample chamber (19), and the infrared imagers (7) are connected with a computer through data collection control lines to shoot the internal fracture of the rock and soil from two directions.

9. The rock-soil moisture, heat and force coupling crack simulation device is characterized in that the left, right and rear side wall surfaces of the sample chamber (19) are made of composite plates formed by stainless steel and polystyrene foam plastic plates, a glass door is installed on the front wall surface of the sample chamber (19), a wire mesh is installed on the glass door, and a stainless steel plate is arranged on the top of the sample chamber (19).

10. A fracture simulation test method for rock-soil moisture, heat and force coupling, which is characterized in that the fracture simulation device for rock-soil moisture, heat and force coupling according to any one of claims 1 to 9 is adopted, and the method is specifically carried out according to the following steps:

s1: dividing a rock-soil sample into a plurality of layers with equal height, sleeving rubber membranes (10) with different layers on each layer of the rock-soil sample according to a test scheme, and respectively installing three water seeping devices on the upper part, the middle part and the lower part of a rock-soil sample; the permeable stone (8) is placed at the center of the bottom of the sample chamber (19), a rock-soil sample is placed on the permeable stone (8), the sample chamber (19) is sealed, the sample chamber (19) is ensured not to be subjected to water seepage during a test, and the influence of the external environment on the rock-soil sample is reduced;

s2: the method comprises the following steps of enabling a water conveying pipe (18) on a Markov bottle (12) to penetrate through a side vertical surface of a sample chamber (19), adjusting the position of an outlet end of the water conveying pipe (18) according to test requirements, enabling a water outlet of the water conveying pipe (18) to be positioned at the same horizontal plane with the top of a corresponding water seeping device, firstly injecting water into the water seeping device, then opening a valve (20) on the corresponding water conveying pipe (18), and setting the opening and closing time of an automatic valve on the water conveying pipe (18) corresponding to an upper water seeping device (22); turning on/off the spotlight (14) according to the time set by the test scheme, and adjusting to the required illumination intensity and illumination area;

s3: according to the test scheme, the set temperature of the temperature controller (11) is adjusted, so that the heating plate (6) and the micro fan (5) work, the constant temperature in the environment simulation box (3) is maintained, and the relatively stable underground temperature is simulated;

s4: and simultaneously starting the microwave heating device (9) and the infrared imager (7), wherein the frequency of the microwave heating device (9) is 420-445 MHz, and the infrared imager (7) records the internal fracture morphology of the rock-soil sample in the whole heating process and stores the internal fracture morphology in the computer.

Background

The soil body environmental simulation experimental device mainly simulates the humidity and the temperature of the upper surface of the soil body, and is difficult to obtain the internal crack development rule of the soil body in the test process.

In practical application, the existing experimental device has the following disadvantages: first, the existing device only considers the upper part and the bottom water seepage simulation, and does not realize the middle part water seepage simulation. Secondly, the existing test device does not realize the effect of carrying out the wet-thermal power coupling to the ground, is difficult to simulate the influence of groundwater and stress in the ground that the ground received in the actual conditions. Thirdly, the final fracture shape can be obtained only by surface observation or nuclear magnetic resonance technology, the development rule of the internal fracture shape in each test stage cannot be observed, in addition, the precision of the surface observation is difficult to guarantee, and the nuclear magnetic resonance technology has high cost.

Disclosure of Invention

In order to solve the problems, the invention provides a fracture simulation device for coupling moisture, heat and force of rock soil, which can accurately simulate the influence of the coupling moisture, heat and force of a rock soil sample on a fracture under the conditions of external illumination, water immersion and pressure, can obtain the fracture development form and the development process of the rock soil sample under the conditions of coupling moisture, heat and force, and solves the problems in the prior art.

The invention also aims to provide a fracture simulation method for the coupling of moisture, heat and force of rock soil.

The invention adopts the technical scheme that the fracture simulation device for coupling the moisture, heat and force of rock soil comprises a test box, an environment temperature and humidity control system and a measuring system;

the test box is used for placing a rock-soil sample and simulating the humidity, the temperature and the illumination environment of the rock-soil sample;

the environment temperature and humidity control system is used for controlling the humidity and the temperature;

the rock-soil sample is wrapped with rubber membranes with different layers along with the change of the height of the sample and is used for simulating the confining pressure applied to the rock-soil sample;

the measuring system comprises a temperature sensor, a microwave heating device and an infrared imager;

the temperature sensor is used for monitoring the temperature of the rock-soil sample;

the microwave heating device is used for heating water in the rock-soil sample by microwaves;

the infrared imager is used for recording the form and the change of water in the rock-soil sample in the whole microwave heating process, and the form and the change of the internal cracks of the rock-soil sample are obtained.

Furthermore, the test box comprises an environment simulation box, the box wall of the environment simulation box adopts a heat insulation structure, a sample chamber is arranged in the environment simulation box, the wall surface of the sample chamber adopts a microwave isolation structure, and a rock soil sample is placed in the sample chamber.

Furthermore, an upper water seeping device is installed on the upper portion of the rock-soil sample, the upper water seeping device comprises a cylindrical barrel, the diameter of the barrel is the same as that of the sample, a PVC permeable membrane is arranged at the bottom of the barrel and is in contact with the top of the rock-soil sample, the upper water seeping device is connected with a Ma bottle through a corresponding water conveying pipe and used for maintaining the height of water in the upper water seeping device, and an automatic valve is installed on the water conveying pipe connected with the upper water seeping device and used for conveying water to the upper water seeping device at regular time to simulate surface retention water;

the middle part of the rock-soil sample is provided with a middle water seepage device, namely an annular water seepage device, the annular water seepage device comprises a cylinder body with a circular cross section, the inner diameter of the cylinder body is the same as the diameter of the rock-soil sample, the inner side wall of the cylinder body is provided with a PVC water permeable membrane, the annular water seepage device is connected with a Ma bottle through a corresponding water delivery pipe and is used for controlling the water seepage degree of the annular water seepage device, and the annular water seepage device seeps water to the upper and lower directions of the sample through the PVC water permeable membrane;

the lower part infiltration ware is installed to the lower part of ground sample, and the lower part infiltration ware includes cylindric barrel, and ground sample diameter is less than the diameter of barrel, and the lower part infiltration ware links to each other with the Ma shi bottle through the raceway that corresponds, and the groundwater water level height of simulation, lower part infiltration ware pass through permeable rock to the infiltration of ground sample.

Furthermore, a spotlight with adjustable height and angle is arranged above the sample chamber.

Further, the heating plate is installed in the environmental simulation case, and a plurality of micro fans are installed to the inside wall of environmental simulation case for blow hot-air to the position far away from the heating plate, make the heating of environmental simulation case more even.

Furthermore, a temperature sensor is arranged in the sample chamber, the temperature sensor is electrically connected with a temperature controller through a lead, and the temperature controller is electrically connected with the heating plate and is used for controlling the heating plate to be opened or closed according to the temperature measured by the temperature sensor; the temperature sensor is electrically connected with a display screen of the environment simulation box through a lead and is used for reading and displaying temperature data measured by the temperature sensor.

Furthermore, the microwave heating device is arranged inside the side wall of the sample chamber, the side wall of the sample chamber provided with the microwave heating device is of a microwave isolation structure, so that microwave energy is transmitted into the sample chamber to rapidly raise the temperature of water inside the rock soil sample, and the microwave heating device is connected with a computer through a data collection control line.

Furthermore, the infrared imaging devices are at least two and are respectively arranged on the inner sides of two side walls of the sample chamber, which are vertical to each other, and the infrared imaging devices are connected with a computer through data collection control lines and shoot cracks in the rock and soil from two directions.

Furthermore, the left, right and rear side wall surfaces of the sample chamber are made of composite plates consisting of stainless steel and polystyrene foam plastic plates, the front wall surface of the sample chamber is provided with a glass door, the glass door is provided with a wire netting, and the top of the sample chamber is provided with a stainless steel plate.

A rock soil moisture, heat and force coupling fracture simulation test method is carried out by adopting the simulation device according to the following steps:

s1: dividing a rock-soil sample into a plurality of layers with equal height, sleeving rubber membranes with different layers on each layer of the rock-soil sample according to a test scheme, respectively installing three water seeping devices on the upper part, the middle part and the lower part of a rock-soil sample, placing permeable stones at the centers of the bottoms of sample chambers, placing the rock-soil sample on the permeable stones, sealing the sample chambers, ensuring that the sample chambers cannot seep water during testing, and reducing the influence of the external environment on the rock-soil sample;

s2: the water conveying pipe on the Mariotte bottle penetrates through the side vertical surface of the sample chamber, the position of the outlet end of the water conveying pipe is adjusted according to the test requirements, the water outlet of the water conveying pipe and the top of the corresponding water seeping device are positioned on the same horizontal plane, water is firstly injected into the water seeping device, then the valve on the corresponding water conveying pipe is opened, and the opening and closing time of the automatic valve on the water conveying pipe corresponding to the water seeping device on the upper portion is set; turning on/off a spotlight according to the time set by the test scheme, and adjusting the spotlight to the required illumination intensity and illumination area;

s3: according to the test scheme, the set temperature of the temperature controller is adjusted, so that the heating plate and the micro fan work, the constant temperature in the environment simulation box is maintained, and the relatively stable underground temperature is simulated;

s4: and simultaneously starting a microwave heating device and an infrared imager, wherein the frequency of the microwave heating device is 420-445 MHz, and the infrared imager records the internal fracture morphology of the rock soil sample in the whole heating process and stores the internal fracture morphology in a computer.

The invention has the beneficial effects that:

the device provided by the invention simulates the confining pressure, heat and water seepage of a rock-soil sample in soil, and is additionally provided with middle water seepage, so that the influence of the wet, heat and force coupling action of the rock-soil sample on the cracks in the external illumination, water immersion and pressure bearing can be accurately simulated, the water in the sample is heated by microwaves within a certain time, the temperature difference between the water and the soil in the formed sample is formed, the sample cracks are filled with water in the heating process, the crack development form and the development process of the rock-soil sample under the wet, heat and force coupling action can be obtained through a high-sensitivity infrared imager, the crack form development rule of the tested silt rock-soil sample is obtained, the crack rate and the mechanical property of the sample are obtained through the test, the influence of the wet and heat coupling action on the rock-soil crack development rule is conveniently researched, and the device has great significance for the engineering application of rock-soil.

The simulation device has the advantages of simple structure, convenient operation, lower cost, simple production, convenient assembly and disassembly and repeated use.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is an overall front view of the present invention.

Fig. 2 is a left side view of fig. 1.

Fig. 3 is a top view of fig. 1.

Fig. 4 is a schematic structural diagram of a top cover in an embodiment of the invention.

Fig. 5 is an overall view of a mahalanobis bottle in an embodiment of the present invention.

Fig. 6 is a top view of the water seepage device in the embodiment of the invention.

Fig. 7 is a schematic structural diagram of a metal interface in an embodiment of the invention.

In the figure, 1, a metal interface, 1-1, a horizontal telescopic pipe, 1-2, a rotating shaft, 1-3, a fixed structure, 2, a cylinder, 3, an environment simulation box, 4, a lead, 5, a micro fan, 6, a heating plate, 7, an infrared imager, 8, a permeable stone, 9, a microwave heating device, 10, a rubber film, 11, a temperature controller, 12, a Ma's bottle, 13, a lifting rod, 14, a spotlight, 15, an annular ribbed plate, 16, a top cover, 17, an annular water seeping device, 18, a water pipe, 19, a sample chamber, 20, a valve, 21, a gap, 22, an upper water seeping device and 23, a lower water seeping device.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the case of the example 1, the following examples are given,

a rock soil moisture, heat and force coupling fracture simulation device is shown in figures 1-3 and comprises a test box, an environment temperature and humidity control system and a measurement system;

the test box is used for placing a rock-soil sample and simulating the humidity, the temperature and the illumination environment of the rock-soil sample;

the test box includes environmental simulation case 3, and the tank wall of environmental simulation case 3 adopts insulation construction, and environmental simulation case 3 is inside to be equipped with sample chamber 19, and the wall of sample chamber 19 adopts and separates the microwave structure, and the ground sample has been placed to sample chamber 19 inside.

The environmental simulation box 3 is of a box-type structure with an unsealed top end, the top end of the box-type structure is detachably connected with a top cover 16, and an annular ribbed plate 15 is arranged on the inner side wall of the environmental simulation box 3 below the top cover 16 and used for supporting the top cover 16; the bottom surface and four side vertical surfaces of the environment simulation box 3 are of a double-layer structure formed by bonding glass and polystyrene foam plastics and have the functions of heat preservation and moisture preservation.

As shown in fig. 4, the top cover 16 is a composite plate formed by bonding a stainless steel plate with a length of 66cm, a width of 36cm and a height of 5cm with a polystyrene foam plastic plate; a rectangular notch 21 with the length of 7cm and the width of 7cm is arranged at the position of the top cover 16 corresponding to the sample chamber 19, and an iron sheet with the length of 8cm, the width of 8cm and the thickness of 0.5cm is arranged at the position of the rectangular notch 21 to cover the sample chamber 19; the left side and the right side of the top of the test box are respectively provided with a stainless steel cylinder 2 with the diameter of 1cm and the height of 20 cm.

The front side surface of the environment simulation box 3 is provided with a cuboid notch 21, the height of the notch 21 is 40cm, the width of the notch 21 is 20cm, and the length of the notch 21 along the front-back direction is 5 cm; six sides of the notch 21 are enclosed to form a sample chamber 19, the left, right and rear side wall surfaces of the sample chamber 19 are made of composite plates consisting of stainless steel and polystyrene foam plastic plates, the sides of the composite plates are mutually bonded, the thickness of the composite plates is 5cm, wherein the inner side of the composite plates is made of stainless steel materials with the thickness of 0.5cm, and the outer side of the composite plates is made of polystyrene foam plastic with the thickness of 4.5 cm. The front wall of the sample chamber 19 shares the front wall of the environment simulation box 3, a glass door is arranged on the front wall of the sample chamber 19, and a wire mesh is arranged on the glass door, so that a sample can be conveniently placed in the sample chamber 19 and can be observed and tested through glass; the top of the sample chamber 19 is provided with a stainless steel plate, and both the stainless steel plate and the wire mesh can isolate microwave radiation. The left side panel and the right side panel of the sample chamber 19 are 25cm in height, 17cm in width and 5cm in thickness, a piece of sponge is placed on the bottom surface of the sample chamber 19, and a stainless steel U-shaped clamp tube is adhered to the top of the inner side of the side vertical panel of the sample chamber 19 and used for controlling the height of the outlet end of the water conveying pipe 18. The test box is 80cm long, 50cm wide and 40cm high; the cross section of the annular ribbed plate 15 is 5cm wide and 5cm high.

Simulating the humidity of a rock soil sample:

as shown in fig. 5-6, an upper water seeping device 22 is installed on the upper portion of the rock-soil sample, the upper water seeping device 22 comprises a cylindrical barrel body with a height of 2cm and a diameter of 12cm, the diameter of the barrel body is the same as the diameter of the sample, the barrel body can be made of plastic materials, a PVC permeable membrane is arranged at the bottom of the barrel body and is in contact with the top of the sample, the upper water seeping device 22 is connected with the mahalanobis bottle 12 through a corresponding water conveying pipe 18 and is used for maintaining the height of water in the upper water seeping device 22, and an automatic valve is installed on the water conveying pipe 18 connected with the upper water seeping device 22 and is used for conveying water to the; the upper water seepage device 22 can store water, and the water seeps downwards from the upper part of the rock soil sample through the PVC water permeable membrane.

The mid-mounting of ground sample has middle part infiltration ware, annular infiltration ware 17 promptly, annular infiltration ware 17 includes that the cross section is annular barrel, height 2cm, external diameter 16cm, internal diameter 12cm, the internal diameter of barrel is the same with ground sample diameter, the inside wall of barrel is equipped with the PVC porous membrane, annular infiltration ware 17 links to each other with mah-jong bottle 12 through the raceway 18 that corresponds, a height for maintaining annular infiltration ware 17 normal water, and then control annular infiltration ware 17's infiltration degree, annular infiltration ware 17 permeates water to the sample upper and lower direction through the PVC porous membrane.

The lower part of the rock soil sample is provided with a lower part water seeping device 23, the lower part water seeping device 23 comprises a cylindrical barrel body with the height of 5cm and the diameter of 16cm, the diameter of the rock soil sample is smaller than that of the barrel body, the lower part water seeping device 23 is connected with the Ma-shi bottle 12 through a corresponding water conveying pipe 18 and is used for maintaining the height of water in the water seeping device at the lower part of the sample and the simulated water level height of underground water, the bottom of the rock soil sample is provided with a permeable stone 8 which is used for ensuring that the bottom of the rock soil sample is fully contacted with bottom layer covering water, and the lower part water seeping device 23 seeps water into the rock soil sample through the permeable stone 8.

The Ma bottle 12 is a cuboid plastic container with a hanging ring on the bottle body, and can be hung on a strong hook of the cylinder 2 outside the environment simulation box 3, and the strong hook is fixed on the top of the cylinder 2; the length of the bottle body of the Malpighian bottle 12 is 5cm, the width is 5cm, the height is 15cm, the diameter of the water delivery pipe 18 is 5mm, the length is 38 cm, and the outlet ends of the water delivery pipes 18 connected with the three water seeping devices are respectively provided with a valve 20. The three water seeping devices act together to simulate underground water, and the PVC water permeable membrane is used for reducing sample damage caused by soil particle stripping when a rock soil sample is soaked in water.

Simulating the temperature of a rock soil sample:

the heating plate 6 is adhered to the inner side of the rear wall of the environment simulation box 3 through heat-insulating glue, is vertically 10cm away from the bottom of the environment simulation box 3 and is used for heating the environment simulation box 3 and the sample chamber 19 and meeting the temperature required by the test.

The heating plate 6 is a silicon rubber heater, and consists of a nickel-chromium alloy heating wire and a silicon rubber high-temperature insulating layer. The silicon rubber high-temperature insulating layer is a sheet (the standard thickness is 1.5mm) formed by compounding silicon rubber and glass fiber cloth, and the silicon rubber heater has good flexibility and has the characteristics of quick heating, uniform temperature, high thermal efficiency, high strength, convenience in use and safety. The length of the heating plates 6 is 20cm, the width of the heating plates is 10cm, the distance between the two heating plates 6 is 12cm, a plurality of micro fans 5 are installed on the inner side wall of the environment simulation box 3, and the micro fans 5 are vertically 15cm away from the floor of the environment simulation box 3; the fan blades face the direction of the central axis of the rear panel of the sample chamber, and blow hot air to a position far away from the heating plate 6, so that the environment simulation box 3 is heated more uniformly; the heating plate 6 is matched with the micro electric fan 5 to ensure that the environment simulation box 3 is heated more quickly and uniformly, and the temperature of the environment simulation box 3 can be controlled and maintained better.

Simulating illumination of rock and soil samples:

a spotlight 14 is arranged 15cm above the sample chamber 19, the spotlight 14 is fixedly connected with the lower end of the lifting rod 13, and the lifting rod 13 is used for adjusting the height of the spotlight 14 so as to control the illumination intensity; the telescopic metal tube is fixedly connected with the cylinder 2 through the rotatable metal interface 1 and is used for adjusting the horizontal position of the spotlight 14; the vertical lifting rod 13 is composed of an aluminum alloy pipe with the length of 5cm and the inner diameter of 1cm and a threaded lantern ring with the length of 2cm and the inner diameter of 0.95cm, one threaded lantern ring is matched with one vertical aluminum alloy pipe, the upper end of the aluminum alloy vertical telescopic pipe is welded with the horizontal telescopic pipe, and the horizontal telescopic pipe 1-1 is made of an aluminum alloy metal pipe. Referring to fig. 7, a metal interface 1 is fixed inside an environment simulation box 3 through a rotating shaft 1-2, a horizontal extension tube 1-1 is fixedly connected with the rotating shaft 1-2 through a fixing structure 1-3, the fixing structure 1-3 can be a bolt structure, and the rotatable metal interface 1 is made of an aluminum alloy material. The angle can be adjusted by directly rotating the horizontal extension tube 1-1 connected with the metal interface 1, and the lamp head is connected with the vertical lifting rod 13, so that the lamp can be fixed after manual adjustment.

Simulating confining pressure of a rock and soil sample:

the rubber membranes 10 with different layers are wrapped outside the rock-soil sample along with the change of the height of the sample and are used for simulating the confining pressure applied to the rock-soil sample.

The environment temperature and humidity control system is used for controlling the humidity and the temperature; the temperature sensors are vertically arranged on the inner side of the rear wall of the sample chamber 19 at equal intervals, the temperature in the sample chamber 19 is monitored through heat conduction induction, the distance between the temperature sensors is 2cm, the distance between the topmost temperature sensor and the annular ribbed plate is 7cm, the temperature sensors are used for collecting temperature data of different positions of the rock soil sample, the temperature sensors are connected with a display screen outside the environment simulation box 3 through leads 4, and the temperature data measured by each temperature sensor can be read and displayed.

The temperature sensor is electrically connected with the temperature controller 11 through a lead 4, the temperature controller 11 is electrically connected with the heating plate 6 and is used for controlling the heating plate 6 to start heating or stop heating according to the temperature measured by the temperature sensor, the temperature controller 11 is arranged outside the environment simulation box 3, and the distance between the temperature controller 11 and the top surface of the environment simulation box 3 is 5 cm; the relatively stable underground temperature is simulated through the environment simulation box 3, the heat conductivity coefficient of the polystyrene foam plastic on the side wall of the sample chamber 19 is 0.033-0.044W/(m DEG C), the temperature of the environment simulation box 3 can be conducted into the sample chamber 19, and the safe use temperature of the polystyrene foam plastic is-150-70 ℃.

The measuring system comprises a temperature sensor, a microwave heating device 9 and a high-sensitivity and high-speed infrared imager 7, wherein the model of the infrared imager 7 is testo865/875, the temperature sensitivity is high, the pixel is good, the heat sensing range is moderate, and the price is moderate.

The temperature sensor is used for monitoring the temperature of the rock-soil sample;

the microwave heating device 9 is used for heating water in the rock soil sample by microwaves;

the microwave heating device 9 is arranged inside the side wall of the sample chamber 19, the side wall of the sample chamber 19 provided with the microwave heating device 9 is free of a stainless steel plate, so that microwave energy is transmitted into the sample chamber 19 to rapidly raise the temperature of water inside the rock soil sample, and the distance between the microwave heating device 9 and the bottom of the environment simulation box 3 is 15 cm; the microwave heating device 9 is 12cm long and 3cm wide, and the microwave heating device 9 is connected with a computer through a data collection control line.

And the infrared imager 7 is used for recording the form and the change of water in the rock-soil sample in the whole microwave heating process, namely the form and the change of the internal cracks of the rock-soil sample.

As shown in fig. 3, two infrared imagers 7 are mounted on the left and back side walls of the sample chamber 19 for viewing the slit from two directions, making the viewing result more stereoscopic. The infrared imager 7 is 18cm away from the bottom of the environment simulation box 3 and is used for observing the internal crack of the sample. The infrared imager 7 is 6cm long and 3cm wide, and the infrared imager 7 is connected with a computer through a data collection control line.

In the case of the example 2, the following examples are given,

a fracture simulation test method for the wet, heat and force coupling of surface rock soil is specifically carried out according to the following steps:

s1: checking whether each part of the instrument is complete and usable, ensuring the inside of the box body to be dry and tidy, dividing the rock soil sample into ten layers with equal height by using a mark pen, according to the test scheme, each layer of rock-soil sample is sleeved with rubber membranes 10 with different layers, three water seeping devices are respectively arranged at the upper part, the middle part and the lower part of a columnar rock-soil sample with the diameter of 12cm and the height of 20cm by waterproof glue, so that the inner side of an annular water seeping device 17 at the middle part is tightly attached to the surface of the rock-soil sample, the water seeping device at the lower part is placed under a sample chamber 19, a permeable stone 8 with the diameter of 12cm and the height of 2cm is arranged at the center of the bottom of the sample chamber 19, a rock-soil sample is placed on the permeable stone 8, the pore part of the sample chamber 19 is bonded by glue to ensure that the sample chamber 19 cannot seep water during the test, a top cover 16 and a glass door are covered, and the stainless steel plate in the gap 21 of the top cover 16 is pulled up, so that heat conduction is isolated, and the influence of the external environment on the rock soil sample is reduced.

S2: closing a valve 20 at the outlet of a water delivery pipe 18 of the Marshall bottle 12, opening a water inlet valve, filling water into the Marshall bottle 12, hanging the Marshall bottle 12 on a strong hook, enabling the water delivery pipe 18 on the Marshall bottle 12 to pass through a stainless steel U-shaped clamping pipe on the side vertical surface of a sample chamber 19 for fixing and adjusting the position of the water delivery pipe 18, adjusting the position of the outlet end of the water delivery pipe 18 according to test requirements, enabling the water outlet of the water delivery pipe 18 and the top of a corresponding water seeping device to be positioned on the same horizontal plane, firstly injecting water into the water seeping device, then opening the valve 20 on the corresponding water delivery pipe 18, setting the opening and closing time of an automatic valve on the water delivery pipe 18 corresponding to the upper water seeping device 22, enabling the upper water seeping device 22 to simulate surface water retention caused by rain, and enabling the lower water seeping device 23 and the middle water seeping device to be kept open to simulate underground water.

Due to the fact that moisture inside the rock soil sample permeates and the moisture above the rock soil sample evaporates, the water level of the empty face at the top of the rock soil sample is lowered, and the water in the Malpighian bottle 12 can automatically maintain the water level height of the empty face at the top of the rock soil sample under the action of atmospheric pressure. Or the stainless steel plate in the notch 21 of the top cover 16 is retracted, the spotlight 14 is turned on/off according to the time set by the test scheme, the height of the spotlight 14 is adjusted according to the requirements of the test scheme, and the area of the spotlight 14 irradiating on the rock-soil sample and the simulated sunlight intensity of the rock-soil sample are adjusted. When the upper water seeping device 22 is opened to simulate the surface water retention (in rainy days), the illumination in rainy days can be achieved, the illumination does not need to be enhanced, and the surface water retention is avoided when strong illumination is simulated (in sunny days).

The spotlight 14 is turned on and,

s3: and (3) switching on a power supply, turning on the micro fan 5, the heating plate 6 and the temperature controller 11 outside the test box in the environment simulation box, and adjusting the set temperature of the temperature controller 11 according to the test plan to enable the heating plate 6 and the micro fan 5 to work and maintain the constant temperature in the environment simulation box 3.

S4: the method comprises the steps of opening a computer connected with a microwave heating device 9 and an infrared imager 7, opening the microwave heating device 9, setting the frequency to be 420-445 MHz, enabling the temperature of water and rock soil to be unobvious when the temperature is lower than the frequency, enabling the temperature of the rock soil sample to be overhigh when the temperature is higher than the frequency and exceeding the set temperature in the test, simultaneously opening the infrared imager 7, recording the internal fracture form of the rock soil sample in the whole heating process, storing the internal fracture form in the computer, and repeating the operation in different stages of the test.

As the rock and soil sample is heated by microwave heating in a mode of heating water molecules, the temperature difference is generated between water and soil in the rock and soil sample in the short-time heating process of 30s, the water is filled in cracks of the rock and soil sample, and the infrared imager can obtain the internal crack forms and the change rules of the rock and soil sample through the water and the soil with different temperatures in the rock and soil sample. Because the high-sensitivity and high-speed infrared imager 7 always shoots the soil body in the heating process, the thermal imaging of the sample is observed in a computer at each heating time period after the heating, and an imaging picture at the optimal heating time is selected. In the embodiment, the silt rock-soil sample is adopted, and the temperature difference is basically not observed within 0-15 s; when the time is 15-26s, temperature difference occurs, but the temperature difference is small, and imaging is not obvious; when the temperature is 26-30s, obvious temperature difference occurs, and fracture imaging is clear; after 32s, the soil body temperature of the rock soil sample rises, the temperature difference decreases, and the fracture imaging definition decreases. Only the temperature distribution of the whole sample can be obtained by the high-sensitivity and high-speed infrared imager 7, and only the shape of the sample can be observed.

And taking out the rock and soil sample in the sample chamber, readjusting the type of the rock and soil sample, and repeating the steps to perform the test of another rock and soil sample.

If the number of bubbles in the cracks of the rock-soil sample is large, the specific heat capacity of air is smaller than that of soil, so that the temperature of the part with more bubbles is between that of water and the soil, and the imaging of the part of cracks is slightly less obvious than that of a water filling part. In the embodiment, the rock soil sample is wholly wrapped by the rubber film 10, and the upper part, the middle part and the lower part are provided with water seepage so as to ensure that the cracks are filled with water, reduce bubbles in the cracks, improve the imaging effect of the cracks and improve the accuracy of the test.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.