A multifunctional experimental system for road engineering in extreme environments

Abstract

The present invention provides a multifunctional experimental system for extreme environment road engineering, including a model box, a loading component, a first temperature control system, a second temperature control system, a water supply system, a road component to be tested, a bottom insulation board, a precipitation system, a lighting system, a wind control system and an ultraviolet system; in the present invention, the experimental system is mainly used to test the service performance of road structures in extreme environments (including plateau permafrost environments and coastal humid and hot environments); through the combined action of various structures, the experimental system can achieve precise control of environmental factors such as temperature, humidity, wind, rain, and ultraviolet rays, and can accurately simulate real extreme environments such as plateau permafrost and coastal humid and hot environments and various traffic loads, and obtain road structure service status data in real time, providing a solid foundation for related research on the degradation and damage disaster mechanism, service life prediction, and service toughness improvement of road structures in extreme environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of extreme environment road engineering, and in particular relates to a multifunctional experimental system for extreme environment road engineering. Background Art

[0002] The permafrost region of the Qinghai-Tibet Plateau is characterized by a harsh environment, characterized by high temperatures, high ice content, and highly unstable permafrost, accounting for a significant proportion (over 50%). This, coupled with the region's variable climate, frequent freeze-thaw cycles, intense radiation, and large diurnal temperature swings, makes the permafrost extremely sensitive to disturbances caused by road construction, leading to frequent thaw subsidence and other problems. Coastal areas experience high temperatures, high humidity, torrential rain, strong winds, and a highly corrosive environment, combined with heavy loads, fatigue, and extreme hazards. These conditions lead to a high incidence of road engineering problems, including frequent collapses. The combined effects of these extreme conditions and heavy loads reduce the resilience and service life of road structures, leading to frequent disasters and posing a serious threat to driving safety. Therefore, research on road performance under the coupled effects of extreme environments and loads is necessary to improve the engineering construction and maintenance, safety resilience, service life, intelligence, and greenness of road structures.

[0003] The Chinese patent application number 202310386318.7 discloses a visual model box for roadbed filler compaction performance and load transfer experiments, which relates to the technical field of road engineering roadbed similarity tests. It solves the problem that conventional physical and mechanical tests have great limitations and cannot accurately show the performance of the actual filled roadbed, while paving experiments consume a lot of manpower and material costs. The model box includes a base, a horizontal electric slide rail, an electric slider 1, a vertical plate, a vertical electric slide rail, an electric slider 2, a model box, a servo motor, a frame, a micro motor, a screw rod, a collar, a guide rod, a rotating rod, a pressure device, an arc frame, a limit slot, a limit sleeve, a block, a limit block, a vertical frame, a slide plate, a horizontal plate, a first limit rod, a first spring, and a rotating plate. It has the characteristics of being able to conveniently and flexibly conduct experimental verification of the roadbed filler compaction performance and load transfer, and can be flexibly adjusted and monitored, and is convenient and flexible to install and use.

[0004] However, in the existing technology, the experimental system cannot simulate multiple extreme environments, making it inconvenient to conduct experiments on roads in multiple extreme environments, thereby reducing the functionality and experimental effect of the experimental system.

[0005] Therefore, it is very necessary to invent a multifunctional experimental system for extreme environment road engineering. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a multifunctional experimental system for extreme environment road engineering to solve the problem in the existing technology that the experimental system cannot simulate multiple extreme environments, is not convenient for conducting experiments on roads in multiple extreme environments, and reduces the functionality and experimental effect of the experimental system.

[0007] To this end, the present invention provides a multifunctional experimental system for extreme environment road engineering, including a model box, a loading component, a first temperature control system, a second temperature control system, a water supply system, a road component to be tested, a bottom insulation board, a precipitation system, a lighting system, a wind control system and an ultraviolet system, wherein the bottom insulation board is installed on the lower side of the interior of the model box, and an installation groove is provided on the upper side of the bottom insulation board; the second temperature control system is installed on the lower side of the interior of the installation groove; the water supply system is installed above the second temperature control system; the road component to be tested is placed above the water supply system; the precipitation system is installed in the middle position of the upper side of the interior of the model box; the first temperature control system is installed at both ends of the upper side of the interior of the model box; the lighting system is installed on the upper side of the interior of the model box, and the lighting system is located between the first temperature control system and the precipitation system; the ultraviolet system is installed on the upper side of the interior of the model box, and the ultraviolet system is located between the precipitation system and the lighting system; the wind control system is installed on both sides of the interior of the model box; the loading component is installed on the outside of the model box, and the end of the loading component is located above the road component to be tested;

[0008] The loading assembly includes a mounting support, a power system, a fixed plate, a transmission assembly and a loading trolley. The mounting support is installed on the outside of the model box; the power system is installed on the end of the mounting support away from the model box; the fixed plate is installed on the end of the mounting support close to the model box; the loading trolley is arranged above the road assembly to be tested; one end of the transmission assembly is installed on the output end of the power system, and the other end of the transmission assembly is installed on the loading trolley, and the middle position of the transmission assembly is slidably matched with the fixed plate.

[0009] Furthermore, the multifunctional experimental system for extreme environment road engineering includes a Fomat wheel, an electric control cabinet and a PLC controller. There are multiple Fomat wheels, and the Fomat wheels are installed at the four corners below the bottom insulation board. After moving to the position, the Fomat wheels are rotated to fix the experimental system on the ground; the electric control cabinet is connected to the mains for power supply; and the PLC controller is powered on to control the system.

[0010] Furthermore, the road component to be tested includes foundation soil, road base, pavement base and pavement asphalt layer, and the foundation soil is placed above the water supply system; the road base, pavement base and pavement asphalt layer are arranged above the foundation soil, and the foundation soil, road base, pavement base and pavement asphalt layer are arranged in sequence from bottom to top; the model box is made of stainless steel plates and organic glass plates, with an observation window, and an inner lining of an insulation board, and the four sides and the top plate of the model box are all detachable and fixed with bolts.

[0011] Furthermore, the power system includes an external motor, a reducer, a frequency converter and a controller; a displacement sensor is installed on the loading trolley, and the displacement sensor collects the motion data of the loading trolley and transmits it to the motion controller in real time, thereby controlling the speed of the external motor to control the speed of the loading trolley. The loading trolley simulates different axle weights by adding weights, and the weights are fixed to the loading trolley with screws. The axle weight is adjusted in the range of 10 to 100 kg according to experimental requirements; the first temperature control system uses a finned tube heat exchanger, a high and low temperature integrated machine and an air cooler to control the ambient temperature. The temperature control range is -30°C to 60°C, and the temperature control accuracy is ±0.1°C. The finned tube heat exchanger is installed on the side wall of the model box and is connected to the high and low temperature integrated machine outside the model box. A temperature sensor is installed inside the model box. The temperature controller controls the temperature inside the model box in a closed loop by controlling the heat generated by the heating tube of the high and low temperature integrated machine through PID. An air cooler is installed behind the finned tube heat exchanger to accelerate heat exchange and make the temperature inside the model box more uniform.

[0012] Furthermore, the second temperature control system controls the bottom plate temperature by circulating the cold bath liquid, with a temperature control range of -20℃~40℃ and a temperature control accuracy of ±0.1℃; the water replenishment system uses a water replenishment and temperature control bearing plate to simulate the replenishment of groundwater to the road structure. The water replenishment and temperature control bearing plate is made of three layers of aluminum alloy, which can transfer the temperature to the road component to be tested faster. A groove is engraved between the bottom layer and the middle layer for the circulation of the cold bath liquid of the cold bath circulator to control the bottom plate temperature. A groove is engraved between the middle layer and the upper layer for uniform water replenishment, which is connected to a constant pressure head controller to provide It provides constant pressure water replenishment, and most of the space between the three layers is a solid structure, which can withstand relatively large stress. There are sealing rings between each layer to ensure the sealing of antifreeze and water replenishment; the precipitation system is equipped with a precipitation device in the area where the road components are to be tested, and the rainfall intensity ranges from 100 to 1500 mm / h, simulating the damage of heavy rain in the coastal environment to the road components to be tested; the wind speed of the wind control system is 5 to 25 m / s, simulating the damage of typhoons in the coastal environment to the road components to be tested; the ultraviolet intensity of the ultraviolet system is 3 to 5 levels, simulating the damage of strong radiation in the plateau environment to the road structure.

[0013] Furthermore, a monitoring and acquisition system is also provided inside the model box, and the monitoring and acquisition system includes a heat flux sensor, a temperature sensor, an ice content sensor, a water content sensor, a distributed optical fiber, a high-resolution linear array camera, and a wireless transmission system to realize real-time monitoring and acquisition of temperature, humidity, force, and deformation; and is equipped with a remote monitoring system to observe the road status in real time.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The experimental system of this invention is primarily used to test the service performance of road structures in extreme environments (including plateau permafrost environments and coastal hot and humid environments), including load-bearing capacity and durability. The experimental system consists of a loading component, a first temperature control system, a second temperature control system, a water supply system, a road component to be tested, a precipitation system, a lighting system, a wind control system, and a UV system. Through the combined action of these components, the experimental system can achieve precise control of environmental factors such as temperature, humidity, wind, rain, and UV light. It can accurately simulate extreme environments such as plateau permafrost and coastal hot and humid environments, as well as various traffic loads, and obtain real-time service status data of road structures. This provides a solid foundation for research on the degradation and damage mechanisms of road structures in extreme environments, service life prediction, and service toughness improvement.

[0016] 2. The present invention uses a loading assembly for loading. Different axle loads are simulated by adding weights. The weights are fixed to the loading cart with screws. The axle load can be adjusted from 10 to 100 kg according to experimental requirements. The loading cart is driven by an external motor, reducer, and inverter, and can complete up to three round trips on the road component to be tested within 1 second. The displacement sensor collects motion data and transmits it to the motion controller in real time, thereby controlling the external motor speed and thus the loading cart speed. The loading assembly can simulate vehicles with different axle loads and different speeds rolling over the road structure and can record the motion data in real time.

[0017] 3. The present invention has two sets of independent temperature control devices. The first temperature control system uses a finned tube heat exchanger, a high and low temperature integrated machine and an air cooler to control the ambient temperature. The temperature control range is -30℃~60℃ and the temperature control accuracy is ±0.1℃. The second temperature control system uses a cold bath circulation machine to control the bottom plate temperature. The temperature control range is -20℃~40℃ and the temperature control accuracy is ±0.1℃. The finned tube heat exchanger is installed on the side wall of the model box and connected to the high and low temperature integrated machine outside the model box. A temperature sensor is installed inside the model box to control the temperature. The device uses PID to control the heat output of the heating tubes of the high and low temperature integrated machine to achieve closed-loop control of the temperature inside the model box. An air cooler is installed behind the finned tube heat exchanger to accelerate heat exchange and make the temperature inside the model box more uniform. The cold bath circulation machine is connected to the bottom plate groove and controls the bottom plate temperature by circulating the cold bath liquid. The first and second temperature control systems can simulate temperature changes in extreme environments outside the road structure (plateau permafrost environment, coastal humid and hot environment) as well as temperature changes in the foundation below the road structure, which is more accurate and close to reality.

[0018] 4. In the present invention, the water replenishment system adopts a water replenishment and temperature control bearing plate to simulate the replenishment of groundwater to the road structure; the water replenishment and temperature control bearing plate is made of three layers of aluminum alloy, which can transfer the temperature to the structure to be tested more quickly; a groove is engraved between the bottom layer and the middle layer for the circulation of the cold bath liquid of the cold bath circulator to control the temperature of the bottom plate; a groove is engraved between the middle layer and the upper layer for uniform water replenishment, connecting the constant pressure head controller to provide constant pressure water replenishment; most of the three layers are solid structures, which can withstand relatively large stress, and there are sealing rings between each layer to ensure the sealing of the antifreeze and water replenishment; the water replenishment and temperature control bearing plate has the functions of water replenishment, temperature control and load bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 It is a structural schematic diagram of the interior of the model box of the present invention.

[0021] Figure 3 It is a structural schematic diagram of the loading component of the present invention.

[0022] Figure 4 It is a structural schematic diagram of the fixing assembly of the present invention.

[0023] In the picture:

[0024] 1. Model box; 2. Loading assembly; 21. Mounting support; 22. Power system; 23. Fixing plate; 24. Transmission assembly; 25. Loading trolley; 3. First temperature control system; 4. Second temperature control assembly; 5. Water supply system; 6. Road component to be tested; 61. Foundation soil; 62. Road base layer; 63. Pavement base layer; 64. Pavement asphalt layer; 7. Bottom insulation board; 8. Precipitation system; 9. Lighting system; 10. Forma wheel; 11. Wind control system; 12. UV system. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings:

[0026] Example:

[0027] As attached Figure 1 To the attached Figure 4 shown

[0028] The present invention provides a multifunctional experimental system for extreme environment road engineering, comprising a model box 1, a loading component 2, a first temperature control system 3, a second temperature control system 4, a water supply system 5, a road component to be tested 6, a bottom insulation board 7, a precipitation system 8, a lighting system 9, a wind control system 11 and an ultraviolet system 12, wherein the bottom insulation board 7 is installed on the lower side of the interior of the model box 1, and an installation groove is provided on the upper side of the bottom insulation board 7; the second temperature control system 4 is installed on the lower side of the interior of the installation groove; the water supply system 5 is installed above the temperature control system 4; the road component to be tested 6 is placed on the water supply system 5. The precipitation system 8 is installed in the middle of the upper side of the model box 1; the first temperature control system 3 is installed at both ends of the upper side of the model box 1; the lighting system 9 is installed on the upper side of the model box 1, and the lighting system 9 is located between the first temperature control system 3 and the precipitation system 8; the ultraviolet system 12 is installed on the upper side of the model box 1, and the ultraviolet system 12 is located between the precipitation system 8 and the lighting system 9; the wind control system 11 is installed on both sides of the model box 1; the loading component 2 is installed on the outside of the model box 1, and the end of the loading component 2 is located above the road component 6 to be tested;

[0029] In this embodiment, the loading component 2 includes a mounting support 21, a power system 22, a fixed plate 23, a transmission component 24 and a loading trolley 25. The mounting support 21 is installed on the outside of the model box 1; the power system 22 is installed on the end above the mounting support 21 away from the model box 1; the fixed plate 23 is installed on the end above the mounting support 21 close to the model box 1; the loading trolley 25 is arranged above the road component 6 to be tested; one end of the transmission component 24 is installed at the output end of the power system 22, and the other end of the transmission component 24 is installed on the loading trolley 25, and the middle position of the transmission component 24 slides with the fixed plate 23.

[0030] In this embodiment, the multifunctional experimental system for extreme environment road engineering also includes a Fomag wheel 10, an electrical control cabinet and a PLC controller. Multiple Fomag wheels 10 are used, and the Fomag wheels 10 are installed at the four corners below the bottom insulation board 7. After moving to the position, the Fomag wheels 10 are rotated to fix the experimental system on the ground; the electrical control cabinet is connected to the mains for power supply; and the PLC controller is powered on to control the system.

[0031] In this embodiment, the road component 6 to be tested includes a foundation soil 61, a road base layer 62, a pavement base layer 63 and a pavement asphalt layer 64. The foundation soil 61 is placed above the water replenishment system 5; the road base layer 62, the pavement base layer 63 and the pavement asphalt layer 64 are arranged above the foundation soil 61, and the foundation soil 61, the road base layer 62, the pavement base layer 63 and the pavement asphalt layer 64 are arranged in sequence from bottom to top.

[0032] In this embodiment, the model box 1 is made of stainless steel plate and organic glass plate, with an observation window and an inner lining of an insulation board. The four sides and the top plate of the model box 1 are all detachable and fixed with bolts. The power system 22 includes an external motor, a reducer, a frequency converter and a controller. A displacement sensor is installed on the loading trolley 25, and the displacement sensor collects the motion data of the loading trolley 25 and transmits it to the motion controller in real time, thereby controlling the speed of the external motor to control the speed of the loading trolley 25. The loading trolley 25 simulates different axle weights by adding weights, and the weights are fixed to the loading trolley 25 with screws. The axle weight is adjusted in the range of 10 to 100 kg according to the experimental requirements; the first temperature control system 3 uses a finned tube heat exchanger, a high and low temperature integrated machine and an air cooler to control the ambient temperature. The temperature control range is -30°C to 60°C, and the temperature control accuracy is ±0.1°C. The finned tube heat exchanger is installed on the side wall of the model box 1 and is connected to the high and low temperature integrated machine outside the model box 1. A temperature sensor is installed inside the model box 1. The temperature controller controls the heating tube heat output of the high and low temperature integrated machine through PID to close the loop and control the temperature inside the model box. An air cooler is installed behind the finned tube heat exchanger to accelerate heat exchange and make the temperature inside the model box 1 more uniform.

[0033] In this embodiment, the second temperature control system 4 controls the bottom plate temperature by circulating the cold bath liquid, with a temperature control range of -20℃ to 40℃ and a temperature control accuracy of ±0.1℃; the water replenishment system 5 uses a water replenishment and temperature control bearing plate to simulate the supply of groundwater to the road structure. The water replenishment and temperature control bearing plate is made of three layers of aluminum alloy, which can transfer the temperature to the road component 6 to be tested more quickly. A groove is engraved between the bottom layer and the middle layer for the circulation of the cold bath liquid of the cold bath circulator to control the bottom plate temperature. A groove is engraved between the middle layer and the upper layer for uniform water replenishment, which is connected to the constant pressure head controller to provide Constant pressure water replenishment: most of the space between the three layers is a solid structure that can withstand relatively large stress. There are sealing rings between each layer to ensure the sealing of antifreeze and water replenishment. The precipitation system 8 is set up in the area of ​​the road component 6 to be tested. The rainfall intensity range is 100-1500mm / h, simulating the damage of heavy rain in coastal environment to the road component 6 to be tested. The wind control system 11 has a wind speed of 5-25m / s, simulating the damage of typhoon in coastal environment to the road component 6 to be tested. The ultraviolet intensity of the ultraviolet system 12 is 3-5 levels, simulating the damage of strong radiation in plateau environment to the road structure.

[0034] In this embodiment, a monitoring and acquisition system is also provided inside the model box 1, and the monitoring and acquisition system includes a heat flux sensor, a temperature sensor, an ice content sensor, a water content sensor, a distributed optical fiber, a high-resolution linear array camera, and a wireless transmission system to realize real-time monitoring and acquisition of temperature, humidity, force, and deformation; and is equipped with a remote monitoring system to observe the road status in real time.

[0035] How it works

[0036] In the present invention, the experimental system is mainly used to test the service performance of road structures in extreme environments (including plateau permafrost environments and coastal hot and humid environments), including load-bearing capacity and durability. The experimental system consists of a model box 1, a loading component 2, a first temperature control system 3, a second temperature control system 4, a water supply system 5, a road component to be tested 6, a precipitation system 8, a lighting system 9, a wind control system 11 and an ultraviolet system 12. Through the combined action of each structure, the experimental system can achieve precise control of environmental factors such as temperature, humidity, wind, rain, and ultraviolet rays. It can accurately simulate real extreme environments such as plateau permafrost and coastal hot and humid environments and various traffic loads, and obtain road structure service status data in real time, providing a solid foundation for related research on the degradation and damage disaster mechanism, service life prediction, and service toughness improvement of road structures in extreme environments.

[0037] Loading is performed using the loading assembly 2, which simulates different axle loads by adding weights. The weights are fixed to the loading trolley 25 with screws, and the axle load can be adjusted from 10 to 100 kg according to experimental requirements. The loading trolley 25 is driven by an external motor, reducer, and inverter, and can complete up to three round trips on the road assembly 6 under test within one second. The motion data is collected by a displacement sensor and transmitted to the motion controller in real time, thereby controlling the external motor speed and thus the speed of the loading trolley 25. The loading assembly 2 can simulate vehicles with different axle loads and different speeds rolling over the road structure and can record the motion data in real time.

[0038] The experimental system has two sets of independently operated temperature control devices. The first temperature control system 3 uses a finned tube heat exchanger, a high and low temperature integrated machine and an air cooler to control the ambient temperature. The temperature control range is -30℃~60℃ and the temperature control accuracy is ±0.1℃. The second temperature control system 4 uses a cold bath circulation machine to control the bottom plate temperature. The temperature control range is -20℃~40℃ and the temperature control accuracy is ±0.1℃. The finned tube heat exchanger is installed on the side wall of the model box and connected to the high and low temperature integrated machine outside the model box. A temperature sensor is installed inside the model box. The temperature controller is controlled by PID controls the heat generated by the heating tubes of the high and low temperature integrated machine to achieve closed-loop control of the temperature inside the model box. An air cooler is installed behind the finned tube heat exchanger to accelerate heat exchange and achieve a more uniform temperature inside the model box. A cold bath circulator is connected to the base plate grooves to control the base plate temperature by circulating cold bath liquid. The first and second temperature control systems 3 and 4 can simulate temperature changes in extreme environments outside the road structure (plateau permafrost environment, coastal humid and hot environment) as well as temperature changes in the foundation below the road structure, providing greater accuracy and practicality.

[0039] The water replenishment system 5 uses a water replenishment and temperature control bearing plate to simulate the replenishment of groundwater to the road structure; the water replenishment and temperature control bearing plate is made of three layers of aluminum alloy, which can transfer the temperature to the structure to be tested more quickly; grooves are engraved between the bottom layer and the middle layer for the circulation of the cold bath liquid of the cold bath circulator to control the temperature of the bottom plate; grooves are engraved between the middle layer and the upper layer for uniform water replenishment, connecting the constant pressure head controller to provide constant pressure water replenishment; most of the three layers are solid structures, which can withstand relatively large stress, and there are sealing rings between each layer to ensure the sealing of antifreeze and water replenishment; the water replenishment and temperature control bearing plate has the functions of water replenishment, temperature control and load bearing.

[0040] Utilizing the technical solution of the present invention, or those skilled in the art designing similar technical solutions inspired by the technical solution of the present invention to achieve the above technical effects, all fall within the scope of protection of the present invention.

Claims

1. A multifunctional experimental system for extreme environment road engineering, characterized by: The invention comprises a model box (1), a loading component (2), a first temperature control system (3), a second temperature control system (4), a water supply system (5), a road component to be tested (6), a bottom insulation board (7), a precipitation system (8), a lighting system (9), a wind control system (11) and an ultraviolet system (12), wherein the bottom insulation board (7) is installed on the lower side of the interior of the model box (1), and an installation groove is provided on the upper side of the bottom insulation board (7); the second temperature control system (4) is installed on the lower side of the interior of the installation groove; the water supply system (5) is installed above the second temperature control system (4); the road component to be tested (6) is placed above the water supply system (5); the precipitation system (8) is installed In the middle of the upper side of the model box (1); the first temperature control system (3) is installed at both ends of the upper side of the model box (1); the lighting system (9) is installed on the upper side of the model box (1), and the lighting system (9) is located between the first temperature control system (3) and the precipitation system (8); the ultraviolet system (12) is installed on the upper side of the model box (1), and the ultraviolet system (12) is located between the precipitation system (8) and the lighting system (9); the wind control system (11) is installed on both sides of the model box (1); the loading component (2) is installed on the outside of the model box (1), and the end of the loading component (2) is located above the road component (6) to be tested; The loading assembly (2) comprises a mounting support (21), a power system (22), a fixing plate (23), a transmission assembly (24) and a loading trolley (25), wherein the mounting support (21) is mounted on the outside of the model box (1); the power system (22) is mounted on an end above the mounting support (21) that is away from the model box (1); the fixing plate (23) is mounted on an end above the mounting support (21) that is close to the model box (1); the loading trolley (25) is arranged above the road assembly (6) to be tested; one end of the transmission assembly (24) is mounted on the output end of the power system (22), and the other end of the transmission assembly (24) is mounted on the loading trolley (25), and the middle position of the transmission assembly (24) is slidably matched with the fixing plate (23).

2. The multifunctional experimental system for extreme environment road engineering according to claim 1, characterized in that: The system also includes a Fomat wheel (10), an electric control cabinet and a PLC controller. The Fomat wheels (10) are used in plurality and are installed at the four corners below the bottom insulation board (7). After being moved to a position, the Fomat wheels (10) are rotated to fix the experimental system on the ground. The electric control cabinet is connected to the mains for power supply. The PLC controller is powered on to control the system.

3. The multifunctional experimental system for extreme environment road engineering according to claim 1, characterized in that: The road component (6) to be tested comprises a foundation soil (61), a road base layer (62), a pavement base layer (63) and a pavement asphalt layer (64); the foundation soil (61) is placed above the water replenishment system (5); the road base layer (62), the pavement base layer (63) and the pavement asphalt layer (64) are arranged above the foundation soil (61), and the foundation soil (61), the road base layer (62), the pavement base layer (63) and the pavement asphalt layer (64) are arranged in sequence from bottom to top.

4. The multifunctional experimental system for extreme environment road engineering according to claim 1, characterized in that: The model box (1) is made of stainless steel plates and organic glass plates, has an observation window, and is lined with a heat-insulating plate. The four sides and the top plate of the model box (1) are detachable and fixed with bolts.

5. The multifunctional experimental system for extreme environment road engineering according to claim 1, characterized in that: The power system (22) includes an external motor, a reducer, a frequency converter and a controller; a displacement sensor is installed on the loading trolley (25), and the displacement sensor collects the motion data of the loading trolley (25) and transmits it to the motion controller in real time, thereby controlling the speed of the external motor to control the speed of the loading trolley (25). The loading trolley (25) simulates different axle loads by adding weights, and the weights are fixed in the loading trolley (25) with screws. The axle weight is adjusted in the range of 10 to 100 kg according to experimental requirements.

6. The multifunctional experimental system for extreme environment road engineering according to claim 1, characterized in that: The first temperature control system (3) uses a finned tube heat exchanger, a high and low temperature integrated machine and an air cooler to control the ambient temperature, with a temperature control range of -30°C to 60°C and a temperature control accuracy of ±0.1°C; the finned tube heat exchanger is installed on the side wall of the model box (1) and is connected to the high and low temperature integrated machine outside the model box (1); a temperature sensor is installed inside the model box (1); the temperature controller controls the temperature inside the model box in a closed loop by controlling the heat generated by the heating tube of the high and low temperature integrated machine through PID; an air cooler is installed behind the finned tube heat exchanger to accelerate heat exchange and make the temperature inside the model box (1) more uniform.

7. The multifunctional experimental system for extreme environment road engineering according to claim 1, characterized in that: The second temperature control system (4) controls the bottom plate temperature by circulating the cold bath liquid, with a temperature control range of -20°C to 40°C and a temperature control accuracy of ±0.1°C; the water replenishment system (5) uses a water replenishment temperature control bearing plate to simulate the supply of groundwater to the road structure. The water replenishment temperature control bearing plate is made of three layers of aluminum alloy and can transfer the temperature to the road component to be tested (6) more quickly. A groove is engraved between the bottom layer and the middle layer for the circulation of the cold bath liquid of the cold bath circulator to control the bottom plate temperature. A groove is engraved between the middle layer and the upper layer for uniform water replenishment, which is connected to a constant pressure head controller to provide constant pressure water replenishment. Most of the three layers are solid structures and can withstand relatively large stress. There are sealing rings between each layer to ensure the sealing of the antifreeze liquid and the water replenishment.

8. The multifunctional experimental system for extreme environment road engineering according to claim 1, characterized in that: The precipitation system (8) is provided with a precipitation device in the area of ​​the road component (6) to be tested, with a rainfall intensity ranging from 100 to 1500 mm / h, simulating the damage to the road component (6) caused by a rainstorm in a coastal environment; the wind control system (11) has a wind speed of 5 to 25 m / s, simulating the damage to the road component (6) caused by a typhoon in a coastal environment; and the ultraviolet intensity of the ultraviolet system (12) is 3 to 5 levels, simulating the damage to the road structure caused by strong radiation in a plateau environment.

9. The multifunctional experimental system for extreme environment road engineering according to claim 1, characterized in that: The model box (1) is also provided with a monitoring and acquisition system inside, and the monitoring and acquisition system includes a heat flux sensor, a temperature sensor, an ice content sensor, a water content sensor, a distributed optical fiber, a high-resolution linear array camera, and a wireless transmission system, so as to achieve real-time monitoring and acquisition of temperature, humidity, force, and deformation; and is equipped with a remote monitoring system to observe the road status in real time.

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