A device and method for testing the whole process of highway slope collapse

Abstract

The present application relates to a kind of highway slope collapse whole process test device and method, device includes water supply tank, water collecting tank, upper water collecting device, rainfall device, model box, road surface cyclic loading device, drainage device, simulation highway, laser emission and optical projection device and image acquisition device;Water supply tank is connected with the rainfall device, upper water collecting device and simulation highway;Water collecting tank and the drainage device are connected with one side of model box;Upper water collecting device and rainfall device are set in the upper portion of model box;Simulation highway is set in the inside of model box, and is provided with cyclic loading device on it;Laser emission and optical projection device are set in the upper portion of simulation highway in model box, and image acquisition device is set in the front of model box outside, mixed solution is formed by white oil and n-dodecane mixing.This application can simulate a variety of hydrogeological conditions, can more truly simulate bedrock fissure development and its bedrock fissure water seepage effect.

Description

Technical Field

[0001] This invention relates to the field of highway landslide testing technology, and in particular to a testing device and method for the entire process of highway slope landslide. Background Technology

[0002] With the continuous expansion of highway construction and the extension of service life, the safety of highway slopes has become increasingly prominent. Especially in mountainous or hilly areas, slopes are susceptible to landslides and other geological disasters due to the combined effects of rainfall, surface runoff, and bedrock fissure water, seriously threatening the structural safety and traffic flow of highways. Landslide model tests can systematically reveal the induction mechanisms and evolution patterns of landslide disasters, providing theoretical basis and technical support for landslide prevention and control. Physical model tests can systematically reveal the induction mechanisms and evolution patterns of landslide disasters. These tests can establish slope models at a similarity ratio and reproduce the effects of soil, bedrock fissure water, and rainfall on a scale. This allows for the direct and controlled study of the occurrence mechanisms and influencing factors of slope landslides, providing reliable experimental evidence for analyzing landslide evolution patterns. It is an important technical means to solve the difficult problems in the research of highway slope landslide mechanisms.

[0003] Current model tests used for studying highway landslide mechanisms mostly employ multidimensional semi-partial models, which insufficiently consider pavement loads, geological strata distribution, overlying water catchment, and groundwater conditions. To a certain extent, they fail to accurately reproduce the highway geological structure and mechanical response characteristics. This experimental approach presents a certain degree of bias in the study of highway landslide formation mechanisms, easily leading to deviations in the evolution of landslides under complex environments, thus affecting the accurate assessment of landslide risks and the scientific formulation of prevention and control measures. Furthermore, existing experimental models still have shortcomings in simulating bedrock fissure water, making it difficult to realistically reproduce the entire process of bedrock fissure water infiltration and erosion after the development of bedrock fissures. Simultaneously, the soil and water loss process caused by bedrock fissure water is also difficult to monitor effectively. Summary of the Invention

[0004] In order to overcome the above-mentioned problems in the existing technology, the present invention provides a test device and method for the whole process of highway slope collapse, which is used to solve the above-mentioned problems in the existing technology.

[0005] A test device for the entire process of highway slope collapse, the device includes a water supply tank, a water collection tank, an upper water collection device, a rainfall device, a model box, a road surface cyclic load device, a drainage device, a simulated highway, a laser emission and optical projection device, and an image acquisition device; The water supply tank is connected to the rainfall device, the upper water collection device, and the simulated road to provide a source of mixed liquid. The water collection tank and the drainage device are connected to one side of the model box, and are used to collect and provide the discharged mixture, respectively. The upper water collection device and the rainfall device are located on the upper part of the model box, and are used to provide upper collection of mixed liquid and rainfall simulation, which is achieved by the mixed liquid; The simulated highway is set inside the model box and is equipped with a cyclic load device to provide cyclic loads for vehicles on the simulated highway. The laser emitting and optical projection device is located on the upper part of the simulated road inside the model box, and is used to form a speckle optical pattern. The image acquisition device is located directly in front of the outside of the model box and is used to record the test process. The mixture is formed by mixing white oil and n-dodecane.

[0006] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the simulated highway includes bedrock fissure material, bedrock material, transparent soil slope material and pavement material, wherein the bedrock material is disposed at the bottom of the model box, the transparent soil slope material is disposed on the upper surface of the bedrock material, the pavement material is located above the transparent soil slope material, and the bedrock fissure material is disposed inside the bedrock material.

[0007] In addition to the aspects and any possible implementations described above, a further implementation is provided, which further includes a rainwater supply pipeline, an upper water collection and supply pipeline, a bedrock fissure water supply pipeline, a surface drainage pipeline, and a groundwater drainage pipeline, wherein one end of the rainwater supply pipeline is connected to the rainwater receiving device, and the other end is connected to the water supply tank; one end of the upper water collection and supply pipeline is connected to the upper water collection device, and the other end is connected to the water supply tank; one end of the bedrock fissure water supply pipeline extends into a pre-set channel inside the bedrock material, forming an indirect communication with the bedrock fissure material through the channel, and the other end is connected to the water supply tank; one end of the surface drainage pipeline is connected to the drainage device, and the other end is connected to the water collection tank; one end of the groundwater drainage pipeline is connected to the bottom right side wall of the model box, and the other end is connected to the water collection tank.

[0008] In addition to the aspects described above and any possible implementations, a further implementation is provided, wherein the water supply tank includes a rainwater delivery pipe interface, a rainwater delivery control module, a rainwater delivery switch, a rainwater flow control valve, an upper water collection and delivery pipe interface, an upper water collection and delivery control module, an upper water collection and delivery switch, an upper water collection flow control valve, a bedrock fissure water delivery pipe interface, a bedrock fissure water delivery control module, a bedrock fissure water delivery switch, and a bedrock fissure water flow control valve, wherein the rainwater delivery pipe interface is connected to a rainwater supply pipeline, and the rainwater delivery control module controls the rainwater delivery switch. The system enables rainfall delivery, with the rainfall flow control valve controlling the amount of rainfall delivered. The upper water collection and delivery pipe interface connects to the upper water supply pipeline, and the upper water collection and delivery control module controls the upper water collection and delivery switch to achieve upper water delivery. The upper water collection flow control valve controls the amount of water delivered from the upper water collection. The bedrock fissure water delivery pipe interface connects to the bedrock fissure water supply pipeline, and the bedrock fissure water delivery control module controls the bedrock fissure water delivery switch to achieve bedrock fissure water delivery. The bedrock fissure water control valve controls the amount of bedrock fissure water delivered.

[0009] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein the water collection tank includes a surface drainage pipe interface, a surface drainage control module, a surface drainage switch, a surface drainage flow control valve, a groundwater drainage pipe interface, a groundwater drainage control module, a groundwater drainage switch, and a groundwater drainage flow control valve, wherein the surface drainage pipe interface is connected to a surface drainage pipeline, and the surface drainage control module controls the surface drainage switch to achieve surface drainage, and the surface drainage flow control valve controls the amount of surface water collected; the groundwater drainage pipe interface is connected to a groundwater drainage pipeline, and the groundwater drainage control module controls the groundwater drainage switch to achieve groundwater drainage, and the groundwater drainage flow control valve controls the amount of groundwater collected.

[0010] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the model box includes a box support and a plurality of model baffles; the model baffles are all made of transparent acrylic plastic sheets, each model baffle is fixedly installed on the box support, and filter plates are provided on opposite sides inside the model box.

[0011] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the bedrock fracture material is a mixture of paraffin solution and open-cell polyurethane foam in equal mass ratios.

[0012] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the laser emitting and optical projection device is a laser projector, and the laser support is fixed at the middle position of the upper edge of the right-side filter partition, including a horizontal fixing part and a vertical lifting part, wherein the horizontal fixing part is connected to the filter partition, and the vertical lifting part is connected to the laser projector.

[0013] The present invention also provides a test method for the whole process of highway slope collapse, the method is implemented by the device described above, and includes the following steps: S1. Assemble the model box, install all pipelines and lay filter baffles, road cyclic load device, drainage device, bedrock fissure material, bedrock material, transparent soil slope material and road material in it; S2. After the static model box is stabilized, adjust the preset water supply flow rates of the upper water collection, rainfall and bedrock fissure water in the water supply tank, and set the initial hydrological conditions; S3. Adjust the preset drainage flow rates of surface drainage and groundwater drainage in the water collection tank, set the initial drainage conditions, and start the water collection tank; S4. Activate the laser projector to generate a speckle pattern on the surface of the slope composed of transparent soil material, and turn on the image acquisition device to prepare to record the movement of soil particles and the seepage process. S5. Activate the road surface cyclic loading device to apply vehicle loads of predetermined frequency and intensity to simulate highway traffic loads; S6. Start the water supply tank to supply water to the rainmaking device, the upper water collection device and the bedrock fissure material respectively, to simulate the process of natural rainfall, surface runoff injection and bedrock fissure water seepage; S7. During the test, the slope deformation and transparent soil test image information were continuously monitored and recorded using an image acquisition device to obtain soil particle movement characteristic parameters; S8. The test continues until a significant landslide occurs on the slope. Then all devices are stopped and the test is terminated. The changes in the simulated highway slope are determined based on the recorded monitoring data and the processed image feature parameters.

[0014] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein the specific process of determining the simulated highway slope change in S8 includes: S81. Determining the displacement velocity of the transparent soil slope based on the time interval between a monitored video frame and the displacement of the transparent soil slope during that time interval and the simulated highway landslide time. S82. Calculate the soil loss volume, shear strain, and yield shear strain of the transparent soil slope. S83. If the shear strain is greater than or equal to the yield shear strain, then it is determined that there is a potential sliding surface in the transparent soil slope. S84. Divide the potential sliding surface into several points, and sum the distances between every two points to obtain the length of the potential sliding surface; S84. Determine the instantaneous safety factor of the slope based on the length of the potential sliding surface and its angle with the horizontal plane, the volume of soil loss and displacement velocity, and the acceleration due to gravity. S85. The instantaneous safety factor is compared with the set critical landslide coefficient to determine the deformation of the simulated highway slope.

[0015] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the model box is assembled from a box support and several model baffles; the model baffles are all made of transparent acrylic plastic sheets, and each model baffle is fixedly installed on the box support by means of threaded connection.

[0016] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the bedrock material is composed of waterproof concrete, the transparent soil slope material is composed of fused silica sand particles, and the fluids circulating in the water supply tank, water collection tank, rainwater supply pipeline, upper water collection pipeline, and bedrock fissure water supply pipeline are all mixtures of white oil and n-dodecane. This mixture has both fluidity and solubility for paraffin, which satisfies the seepage simulation requirements and enables the dynamic development simulation of bedrock fissures.

[0017] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the bedrock fracture material is prepared by mixing and curing a paraffin wax PW solution with an open-cell polyurethane foam OPF in a 1:1 ratio; since the cured paraffin wax PW gradually dissolves in white oil at room temperature, the white oil is supplied through a bedrock fracture water delivery pipeline, thereby simulating the development process of bedrock fractures and the generation of bedrock fracture water.

[0018] In addition to the aspects and any possible implementations described above, a further implementation is provided in which filter baffles are provided on both sides of the bedrock material inside the model box, and the filter baffles are detachably fixedly connected through pre-set snap-fits on the inside of the model box; the filter baffles are also provided with support brackets, which are used to fix the raining device and the upper water collection device respectively through threaded connections.

[0019] In addition to the aspects and any possible implementations described above, a further implementation is provided in which a laser bracket is provided at the middle of the upper edge of the right-side filter partition. The laser bracket is composed of a horizontal fixing part and a vertical lifting part connected vertically. The horizontal fixing part is connected to the filter partition, and the vertical lifting part is connected to the laser projector and can drive the laser projector to adjust its height in the vertical direction. The laser projector is located between the two filter partitions inside the model box, and its vertical height adjustment range covers the top to bottom surface of the transparent soil slope material.

[0020] Beneficial effects of the present invention Compared with the prior art, the present invention has the following beneficial effects: (1) The road landslide test device of the present invention can arrange bedrock fissures in similar model materials, and their size and location can be determined according to the test requirements. At the same time, by utilizing the properties of paraffin wax PW, which is a hard solid at room temperature and soluble in white oil, and the good permeability and support properties of open-cell polyurethane foam OPF, a test method for road landslides induced by fissure water under different bedrock fissure morphologies was established, realizing the study of the mechanism of bedrock fissure water on landslide evolution at the physical model scale. This physical model test device can provide reliable experimental basis for revealing the mechanism of road landslides, assessing the influence of fissure water, and optimizing protection measures; (2) The highway landslide test method of the present invention observes the evolution of soil erosion under seepage through an image acquisition device, and combines the soil particle characteristic parameters obtained by monitoring to establish a potential sliding surface identification model based on seepage and a calculation method of three thresholds for the four stages of cracking-deformation-movement-sliding, which enriches the technical means of monitoring potential sliding surfaces and assessing slope stability during seepage.

[0021] (3) The road landslide test of the present invention constructs a landslide test model covering the entire structural layers of the road, which can realistically restore the geological structure and mechanical response characteristics, and can realize the coordinated loading of various typical environmental factors such as rainfall, groundwater fluctuation and road load, effectively making up for the defects of the traditional model test environment being single and the local roadbed model being inaccurate, and improving the realism and reliability of the landslide evolution process simulation. (4) The road landslide test device of the present invention can simulate typical disaster-causing conditions such as surface water retention, bedrock fissure water infiltration and drainage system failure, covering multi-source coupling scenarios that may induce landslides during the service of highways, and can reproduce the combined action process of multiple landslide inducing factors, and improve the adaptability of model tests under multiple disaster-causing factor coupling and complex environmental conditions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2This is a top view of the overall structure of an embodiment of the present invention; Figure 3 This is a schematic diagram of the front view of the model box structure according to an embodiment of the present invention; Figure 4 This is a front view structural plan of the water supply tank according to an embodiment of the present invention; Figure 5 This is a top view of the water collection tank structure according to an embodiment of the present invention. Detailed Implementation

[0023] To better understand the technical solution of this invention, the content of this invention includes, but is not limited to, the specific embodiments described below. Similar technologies and methods should be considered within the scope of protection of this invention. To make the technical problems to be solved, the technical solutions, and advantages of this invention clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0024] It should be understood that the embodiments described in this invention are merely some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0025] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0026] like Figure 1 The diagram shows the overall framework of the device of the present invention. The device of the present invention is not limited to specific operating hardware and programming language. It can be written in any language. Therefore, other working modes will not be described in detail.

[0027] A transparent device for the entire process of highway slope landslides induced by multiple factors including meteorological rainfall and hydrogeological conditions includes a water supply tank 1, a water collection tank 2, a rainfall water supply pipeline 3, an upper water collection pipeline 4, a bedrock fissure water supply pipeline 5, a surface drainage pipeline 6, a groundwater drainage pipeline 7, an upper water collection device 8, a rainfall device 9, a model box 10, a filter plate 11, a support bracket 12, bedrock material 13, transparent soil slope material 14, a drainage device 15, a road surface material 16, a laser projector 17, bedrock fissure material 18, a road surface cyclic load device 19, a laser emission and optical projection device, and an image acquisition device. The laser emission and optical projection device uses a laser bracket 20, and the image acquisition device uses an image acquisition device 21.

[0028] The water supply tank 1 is connected to the rainwater supply pipeline 3, the upper water collection pipeline 4, and the bedrock fissure water supply pipeline 5 by a sealed thread, and is used to provide water sources for the rainwater, upper water collection and bedrock fissure water during the test. The water collection tank 2 is connected to the surface drainage pipeline 6 and the groundwater drainage pipeline 7 by a sealed thread, and is used to collect the surface drainage and groundwater drainage during the test and to control the groundwater level in the model box 10. The rainfall water supply pipeline 3 is made of plastic and is connected to the water supply tank 1 and the rainfall device 9 by threaded connection to provide water source for the experimental rainfall; The upper water collection and supply pipeline 4 is made of plastic and is connected to the water supply tank 1 and the upper water collection device 8 by thread, so as to provide water source for the upper water collection device 8. The bedrock fissure water supply pipeline 5 is made of plastic and is connected to the water supply tank 1 by a thread. The end of the pipeline extends into a pre-set seepage channel inside the bedrock material 13 and delivers fluid to the bedrock fissure material 18 through the channel to simulate the development of bedrock fissures and the seepage of fissure water. The surface drainage pipeline 6 is made of plastic and is connected to the water collection tank 2 and the drainage device 15 by threaded connection, providing a passage for collecting and treating surface drainage. The groundwater drainage pipeline 7 is made of plastic and is connected to the water collection tank 2 and the filter plate 11 by threaded connection, providing a passage for collecting and treating groundwater drainage. The upper water collection device 8 is connected to the upper water collection and supply pipeline 4 via a pipeline and is located above and behind the model box 10, and is used to provide upper water collection for the model box 10; The rainfall device 9 is connected to the rainfall supply pipeline 3 and is located above the model box 10 to provide rainfall simulation during the experiment; The model box 10 is made of transparent acrylic plastic sheet and is used to contain bedrock material 13, transparent soil slope material 14, bedrock fracture material 18 and road surface material 16 to form a complete highway slope test model. The filter baffles 11 are made of microporous material and are located on both sides inside the model box 10. They are detachably fixed and installed through pre-set snap-fits on the inside of the model box. They are used to block soil particles of all sizes and conduct water flow. One filter baffle 11 is arranged close to the inner wall of one side of the model box 10, and the other filter baffle 11 is arranged with a reserved space in the inner wall of the other side of the model box 10 to provide space for the arrangement of groundwater. The support bracket 12 is welded to the top of the filter baffle 11 and is fixed to the upper water collection device 8 and the rain device 9 respectively by threaded connection, for supporting and fixing the upper water collection device 8 and the rain device 9; The bedrock material 13 is laid at the bottom of the model box 10 to provide a simulated space for the water to flow above. The transparent soil slope material 14 is located on the upper surface of the bedrock material 13, and is used to realize the visualization observation of soil particle migration and potential sliding surface development and evolution process during seepage. The road surface material 16 is laid on top of the transparent soil slope material 14 to bear and transmit the load applied by the road surface cyclic load device 19. The box contains bedrock material 13, transparent soil slope material 14, and pavement material 16 laid from bottom to top. Together, they form a simulated highway structure: bedrock material 13 provides the bottom support for the highway, transparent soil slope material 14 serves as the main body of the roadbed, and pavement material 16 is laid on top of the main body of the roadbed to form the road surface; the highway slope is an inclined slope formed by the transparent soil slope material 14 extending outward from the box. The slope range is the area of ​​all transparent soil slope material, which is the main irradiation target of the laser projector 17 and the potential area for the development of sliding surfaces.

[0029] The bedrock fissure water supply pipeline 5 is made of plastic and is connected to the water supply tank 1 and the bedrock fissure material 18 by threaded connection to provide water to the bedrock fissure material 18; The drainage device 15 is located on the upper surface of the bedrock material 13, on both sides close to the transparent soil slope material 14, and is arranged close to the side wall of the model box 10. The drainage device 15 is disposed on the upper surface of the bedrock material 13, located on both sides near the transparent soil slope material 14, and is used to provide surface drainage for the model box 10. The laser projector 17 is fixedly installed on the vertical lifting part of the laser bracket 20. The laser projector is driven to adjust its height in the vertical direction by rotating the precision threaded knob on the lifting part, so that the speckle pattern emitted by it can completely cover the top to the bottom of the transparent soil slope material 14, and is used by the image acquisition device 21 for non-contact deformation measurement.

[0030] The transparent soil slope material 14 is composed of fused silica sand particles. The water, drainage or rainfall mentioned in this invention is actually a mixture of white oil and n-dodecane. That is, the liquids used in the water supply tank 1, water collection tank 2, rainfall water supply pipeline 3, upper water collection pipeline 4, bedrock fissure water supply pipeline 5, surface drainage pipeline 6, and groundwater drainage pipeline 7 are all mixtures of white oil and n-dodecane, not water. This mixture has both fluidity and solubility for paraffin, which not only meets the requirements of seepage simulation, but also realizes the dynamic development simulation of bedrock fissures.

[0031] The bedrock fissure material 18 is pre-embedded inside the bedrock material 13 on one side near the transparent soil slope material 14, in direct contact with the bottom of the transparent soil slope. It is prepared by mixing paraffin solution and open-cell polyurethane foam in a 1:1 ratio and then curing it. After the bedrock fissure material 18 dissolves in the mixture, it forms a continuous fissure channel. The mixture seeps directly into the interior of the transparent soil slope material 14 through the fissure channel, reducing the shear strength of the soil, accelerating the development of potential sliding surfaces, and ultimately inducing slope collapse, thus realistically simulating the fissure water-induced disaster process.

[0032] The road cyclic load device 19 is located above the road material 16 and acts on the surface of the road material 16 to provide cyclic loads of road vehicles for the test. The laser support 20 consists of a horizontal fixing part and a vertical lifting part; the horizontal fixing part is connected to the right filter plate by bolts, and the vertical lifting part is equipped with a precision threaded adjustment mechanism, which realizes the lifting and positioning of the laser projector 17 through rotational transmission; The laser projector 17 is adjustable in angle and height via the horizontal fixing part and the vertical lifting part of the laser bracket 20. The speckle pattern emitted by it completely covers the entire area of ​​the highway slope composed of transparent soil slope material, from the bottom of the road surface material 16 (slope top) to the bottom of the transparent soil slope material (slope bottom). The vertical height is adjusted by a precision threaded knob to ensure that the speckle pattern covers the entire area from the top to the bottom of the slope without any blind spots, meeting the requirements for full-area deformation monitoring of slope collapse. The image acquisition device 21 is located directly in front of the model box 10. After the laser projector 17 emits the speckle pattern, it continuously captures the displacement changes of the speckle pattern. Combined with digital image correlation algorithms, it performs grayscale conversion and pixel quantization processing on the acquired image, accurately extracts characteristic parameters such as soil particle movement trajectory and slope deformation, and provides basic data support for subsequent quantitative analysis such as shear strain calculation and potential sliding surface identification.

[0033] Preferably, such as Figure 2 and Figure 3 As shown, the upper water collection device 8 includes an upper water collection base 8-1 and an upper water collection nozzle 8-2. The upper water collection base 8-1 is fixedly installed on the support bracket 12 by threads and is connected to the upper water collection supply pipeline 4 by internal threads; the upper water collection nozzle 8-2 is connected to the outlet of the upper water collection base 8-1 by a quick-connect interface, and the water flow is evenly distributed to each nozzle through the distribution cavity inside the base, so as to evenly spray the water flow above the model box 10, providing a simulated upper water collection working condition for the experiment.

[0034] The rainfall device 9 includes a rainfall base 9-1 and a rainfall nozzle 9-2. The rainfall base 9-1 is fixedly installed on the support bracket 12 by threads and is connected to the rainfall water supply pipeline 3 by internal threads. The rainfall nozzle 9-2 adopts a micro-hole spray structure and is connected to the water outlet of the rainfall base 9-1 by a quick-connect interface. It is used to atomize the water flow and evenly cover the top of the model box 10, providing rainfall conditions of different intensities for the experiment.

[0035] The model box 10 includes a model baffle 10-1 and a box support 10-2. The model baffle 10-1 is made of high-strength transparent acrylic sheet and is detachably connected to the box support 10-2 by bolts, enabling experimental observation and model filling.

[0036] The road surface cyclic load device 19 includes a cyclic load bracket 19-1 and a cyclic load pulley 19-2. The two ends of the cyclic load bracket 19-1 are respectively fixed to the model baffles 10-1 on both sides of the model box 10 by bolts; the cyclic load pulley 19-2 is mounted on the crossbeam of the cyclic load bracket 19-1 by bearings, and its own motor drive system can drive the pulley to reciprocate along the guide rail to simulate the cyclic application of road vehicle load.

[0037] Preferably, such as Figure 4 As shown, the water supply tank 1 includes a rainfall delivery pipe interface 1-1, a rainfall delivery control module 1-2, an upper water collection and delivery pipe interface 1-5, an upper water collection and delivery control module 1-6, a bedrock fissure water delivery pipe interface 1-9, and a bedrock fissure water delivery control module 1-10. Rainfall delivery pipe interface 1-1 is internally threaded to the rainfall supply pipeline 3. The mixed liquid is delivered through the rainfall delivery switch 1-3 in the rainfall delivery control module 1-2, and the delivery flow rate of the mixed liquid is controlled by the rainfall flow control valve 1-4. The upper water collection delivery pipe interface 1-5 is internally threaded to the upper water collection supply pipeline 4. The mixed liquid is delivered through the upper water collection delivery switch 1-7 in the upper water collection delivery control module 1-6, and the delivery flow rate of the mixed liquid is controlled by the upper water collection flow control valve 1-8. The bedrock fissure water delivery pipe interface 1-9 is internally threaded to the bedrock fissure water supply pipeline 5. The mixed liquid is delivered through the bedrock fissure water delivery switch 1-11 in the bedrock fissure water delivery control module 1-10, and the delivery flow rate of the mixed liquid is controlled by the bedrock fissure water flow control valve 1-12.

[0038] Preferably, such as Figure 5As shown, the water collection tank 2 includes a surface drainage pipe interface 2-1, a surface drainage control module 2-2, a groundwater drainage pipe interface 2-5, and a groundwater drainage control module 2-6. The surface drainage pipe interface 2-1 is internally threaded to the surface drainage pipeline 6. Surface drainage is controlled by the surface drainage switch 2-3 in the surface drainage control module 2-2, and the surface drainage flow rate is adjusted by the surface drainage flow control valve 2-4. The groundwater drainage pipe interface 2-5 is internally threaded to the groundwater drainage pipeline 7. Groundwater drainage is controlled by the groundwater drainage switch 2-7 in the groundwater drainage control module 2-6, and the groundwater drainage flow rate is adjusted by the groundwater drainage flow control valve 2-8.

[0039] Preferably, the present invention also provides a testing method for a road testing system, comprising the following steps: (1) Assemble the model box 10, and install the model baffle 10-1 on the box support 10-2 with bolts to form the model box structure; install the filter baffle 11 in the preset position inside the model box 10; lay the bedrock fissure material 18, bedrock material 13, transparent soil slope material 14 and road surface material 16 in sequence inside the box, and install all pipelines, including rainwater supply pipeline 3, upper water collection supply pipeline 4, bedrock fissure water supply pipeline 5, surface drainage pipeline 6 and groundwater drainage pipeline 7; install the drainage device 15 in the predetermined position, and install the road surface cyclic load device 19; (2) After the model is laid, let it stand for 24 hours until the model strata are fully stable. Set the initial flow rate of the upper water collection through the upper water collection flow control valve 1-8, set the initial flow rate of the rainfall through the rainfall flow control valve 1-4, and set the initial flow rate of the bedrock fissure water through the bedrock fissure water flow control valve 1-12 to realize the setting of the initial hydrological conditions. (3) Set the initial flow rate of surface drainage through the surface drainage control module 2-2 and the initial flow rate of groundwater drainage through the groundwater drainage control module 2-6 to realize the setting of initial drainage conditions. After completion, start the water collection tank 2. (4) Start the laser projector 17 and adjust the height of the laser projector by rotating the precision threaded knob on the laser bracket 20 so that the generated speckle pattern completely covers the surface of the transparent soil slope material 14; turn on the image acquisition device 21, adjust the focus and acquisition parameters, and prepare to record the movement of soil particles and the seepage process. (5) Start the road cyclic load device 19, and control the cyclic load pulley 19-2 to reciprocate along the guide rail at a predetermined frequency and intensity through its own motor drive system to simulate the road traffic load. (6) Start the rainfall device 9 through the rainfall transmission switch 1-3 to simulate natural rainfall; start the upper water collection device 8 through the upper water collection transmission switch 1-7 to simulate surface runoff; provide water source to the bedrock fissure material 18 through the bedrock fissure water transmission switch 1-11 to simulate the development of bedrock fissures and the generation of bedrock fissure water, and realize the simulation of composite hydrological conditions. After the water supply tank is activated, the rainfall device 9, the upper water collection device 8, and the bedrock fissure water supply pipeline 5 work simultaneously. The rainfall device 9 sprays the mixed liquid evenly onto the road surface material 16 and the entire transparent soil slope to simulate natural rainfall. The upper water collection device 8 injects the mixed liquid into the area above the highway slope to simulate surface runoff. The bedrock fissure water supply pipeline 5 continuously delivers the mixed liquid to the bedrock fissure material 18, triggering the dissolution of paraffin in the bedrock fissure material 18 and forming a through-type fissure channel. The mixed liquid, as bedrock fissure water, naturally moves within the channel and continuously infiltrates into the interior of the transparent soil slope material 14, reducing the cohesion and shear strength between soil particles and accelerating the development and expansion of the potential sliding surface. The drainage device 15 operates continuously throughout the entire test. The surface drainage pipeline collects the slope runoff, and the groundwater drainage pipeline 7 regulates the groundwater level in the model box 10 to avoid fluid accumulation interfering with the test. The bedrock fracture material 18 began to dissolve immediately after the mixed liquid was injected, and the fracture development process proceeded synchronously with rainfall and surface runoff; (7) During the test, the slope deformation and transparent soil test image information were continuously monitored and recorded by the image acquisition device 21; After grayscale conversion and pixel quantization, the collected image data were used to obtain soil particle movement characteristic parameters through digital image correlation algorithm; (8) The test continues until the slope collapses significantly. All devices are stopped immediately and the test is terminated. All monitoring data and processed image feature parameters are saved for subsequent analysis of slope stability and collapse mechanism, and to determine the changes in the simulated highway slope. (9) Repeat steps (1)-(8) above, and by adjusting the parameter settings of each control module in water supply tank 1 and water collection tank 2, a comparative test of road landslide caused by bedrock fissure water under different hydrological conditions can be carried out.

[0040] The composite hydrological simulation can be flexibly set according to experimental needs. The timing of water supply to the bedrock fissure material 18 can be divided into two modes: First, a preset water supply mode, where a quantitative mixture is injected into the bedrock fissure material 18 before the experiment begins (step 2, setting the initial hydrological conditions), simulating the initial condition where bedrock fissures have developed and connected. Second, a synchronous water supply mode, where, after the water supply tank is activated, different amounts of mixture are simultaneously supplied to the bedrock fissure material along with the rainfall device and the upper water collection device, simulating the dynamic development of bedrock fissures with rainfall and surface runoff. Both modes can be used without supplying water to the bedrock fissure material, allowing for comparative analysis of the impact weight of fissure water on landslides. The simulated highway slope changes are determined based on recorded monitoring data and processed image feature parameters.

[0041] Preferably, the specific process of judging the changes in the simulated highway slope in the aforementioned step (8) includes: (81) Determining the displacement velocity of the transparent soil slope based on the time interval between a certain video frame monitored and the displacement of the transparent soil slope during that time interval and the simulated highway landslide time; (82). Calculate the soil loss volume, shear strain and yield shear strain of the transparent soil slope; (83). If the shear strain is greater than or equal to the yield shear strain, then it is determined that there is a potential sliding surface in the transparent soil slope. (84). Divide the potential sliding surface into several points, and sum the distances between every two points to obtain the length of the potential sliding surface; (85). Determine the instantaneous safety factor of the slope based on the length of the potential sliding surface and its angle with the horizontal plane, the volume of soil loss and displacement velocity, and the acceleration due to gravity. (86). The instantaneous safety factor and the set critical landslide factor are compared to determine the deformation of the simulated highway slope.

[0042] The specific implementation process of this judgment is as follows: This invention uses an image acquisition device to save and record monitoring data and processed image feature parameters to predict changes in highway slopes. It employs a potential sliding surface identification model and a four-stage, three-threshold judgment based on cracking-deformation-dynamic-slip to reflect the evolution characteristics of highway slopes under seepage and load conditions, including the migration of soil particles, the development of shear strain, the formation of a continuous sliding surface, and eventual instability and failure. Accordingly, this invention proposes the following calculation method: Deformation images of the transparent soil slope material 14 were recorded throughout the experiment using image acquisition device 21. The recording area covered by laser projector 17 was the transparent soil slope extending from the upper surface of bedrock material 13 to below road surface material 16. The time T of the road landslide was defined as the specific moment when the slope experienced a significant landslide and the experiment was terminated. Based on digital image correlation analysis, deformation image data continuously acquired before time T were extracted, with the time interval t between the a-th and a+1-th video frames as the basis. a To determine the value at time t, where 'a' is an integer greater than or equal to 1, the deformation difference between adjacent video frames is compared to determine the value at time t. a Displacement L of the target soil during the time interval a The target soil body is the transparent soil slope material 14 body located below the road surface material 16 and above the bedrock material 13. This area is within the irradiation range of the laser projector, and its displacement can be accurately captured by the speckle displacement change.

[0043] The displacement velocity v of the soil is expressed as: (1) In the above formula, v is the displacement velocity of the soil, T is the moment of the road landslide, and t is the displacement velocity of the soil. a L is the time interval. a For in t a Displacement of soil during time period, T, t a and L a The value is known.

[0044] The volume of soil loss can then be expressed as: (2) In the above formula, V is the volume of soil lost, N is the total number of soil particles captured, and d n The equivalent diameter of the nth captured soil particle; N, v (obtained in step (1)) and d n The values ​​are known. The displacement field of the soil particles is obtained. This displacement field is the displacement distribution field of all soil particles in the transparent soil slope material 14. The rectangular coordinates of each particle constitute the basic unit of the displacement field, directly reflecting the positional changes of the soil particles. The shear strain between the soil particles can be calculated, and its expression is: (3) In the above formula, γ(i,j) is the shear strain at the node in the i-th row and j-th column of the virtual computational grid, u(i,j) is the horizontal displacement at the node in the i-th row and j-th column of the computational grid, v(i,j) is the vertical displacement at the node in the i-th row and j-th column of the computational grid, Δy is the vertical physical distance between adjacent nodes in the computational grid, and Δx is the horizontal physical distance between adjacent nodes in the computational grid; γ(i,j), u(i,j), v(i,j), Δy, and Δx are known values. This computational grid is a virtual analysis grid set during the data processing stage. Specifically, the transparent soil slope area covered by laser irradiation is divided into grids with a physical spacing of 1mm × 1mm. The grid nodes correspond one-to-one with the spatial positions of the soil particles, and the displacement data of each node is determined by the average displacement value of the soil particles in the corresponding area. The computational domain and the virtual computational grid cover the same area, i.e., the irradiation range of the laser projector. The grid node is the smallest analytical unit of the computational domain. Shear strain analysis of the entire computational domain is achieved through node displacement calculation, ensuring the rationality and basis of the formula calculation.

[0045] Based on the fundamental principles of the simplified Bishop method in slope stability analysis, and considering the effect of the slope's self-weight stress field, the yield shear strain between soil particles is obtained by the following formula: (4) In the above formula, γ t Let H be the shear strain between particles, H be the height of the slope, θ be the angle of the slope, and g be the acceleration due to gravity, taken as 9.81 m / s².2 H, θ, v (obtained from formula (1)) and g are known values.

[0046] The calculation region is determined by the laser projection range of laser projector 17. By identifying continuous regions within this calculation region where the shear strain reaches or exceeds the yield shear strain, the potential sliding surface can be determined. The formula can be expressed as: (5) In the above formula, S is the potential sliding surface. This represents a two-dimensional planar coordinate system, corresponding to the xy plane of the computational mesh, where (i,j) is the coordinate position of the mesh node in this coordinate system; γ(i,j), γ t S and S are known values.

[0047] Assume a potential sliding surface S comprises p points, where p is a natural number. The points are arranged as follows: they are uniformly selected along the contour edge of the potential sliding surface, covering the start point, end point, and intermediate inflection points, regardless of the regularity of the surface shape, to ensure a complete representation of the actual contour of the sliding surface. If the sliding surface has multiple branches, the points are arranged primarily along the length of the longest branch. The length of the potential sliding surface then satisfies the following condition: (6) In the above formula, L s x is the length of the potential sliding surface. p Let y be the horizontal displacement length at the p-th point. p x is the vertical displacement length at the p-th point; p and y p The value is known.

[0048] Based on the limit equilibrium theory, and considering the geometric characteristics of the sliding surface and the spatial distribution characteristics of the soil motion state, the instantaneous safety factor can be expressed as: (7) In the above formula, C t The instantaneous safety factor is given by t, where t is the instantaneous time, and θ is the angle of the potential sliding surface in the horizontal direction; V, g, L s v and v are known values.

[0049] The instantaneous safety factor C before slope collapse was obtained through multiple tests. d Statistical analysis was performed on the instantaneous safety factor values ​​obtained from all B effective tests, and the arithmetic mean was used as the critical landslide coefficient C. c Its calculation formula can be expressed as: (8) In the above formula, C c C is the critical landslide coefficient. d(b) represents the instantaneous safety factor before slope collapse in the b-th valid test, where B is the number of valid tests used for statistical analysis, and both B and b are natural numbers; C d (b) and B are known values.

[0050] Based on the determined critical landslide coefficient C c and the instantaneous safety factor C under real-time monitoring t The computer data processing system automatically determines the evolution stage of the highway slope based on preset thresholds. The system receives deformed image data transmitted from the image acquisition unit 21 and automatically calculates the critical landslide coefficient C. c and the instantaneous safety factor C under real-time monitoring t Then, based on the three preset thresholds 1.1C c、 1.3C c and C c The evolution of highway slopes is divided into four stages: cracking, deformation, dynamics, and sliding. The results are output to the system terminal. The specific division of the four stages of highway slope evolution is as follows: (1) When At that time, it was determined that the highway slope was in the crack formation stage; (2) When At that time, it was determined that the highway slope was in the plastic deformation stage; (3) When At that time, it was determined that the highway slope was in the stage of local movement; (4) When At that time, it was determined that the highway slope was in the stage of overall landslide.

[0051] By adopting the above technical solution, the present invention has the following advantages compared with the prior art: (1) Bedrock fracture simulation is closer to actual working conditions Existing techniques for simulating bedrock fissures typically require the manual removal of the fissure material after the model is laid. However, this process not only disturbs the experimental model but also causes settlement of the overlying rock material due to the voids at the fissures, thus deviating from the expected experimental plan. This invention uses a 1:1 mixture of paraffin wax (PW) and open-cell polyurethane foam (OPF) to solidify and form a bedrock fissure material. The development process of bedrock fissures is simulated through white oil dissolution, allowing water to naturally migrate within the model. Simultaneously, the excellent support properties of the bedrock fissure material ensure that the fissure channels remain unobstructed under the pressure of the overlying rock mass, avoiding any impact on the model's structural stability. In summary, the technical solution provided by this invention is more closely aligned with actual working conditions.

[0052] (2) Improved methods for identifying the evolution and stability monitoring of potential sliding surfaces under seepage conditions Existing methods for identifying potential sliding surfaces and determining their stability typically employ point-based physical sensors such as displacement sensors and inclinometers to monitor the overall deformation characteristics of the slope surface. However, these methods can only provide a rough assessment of potential sliding surfaces and slope stability based on local displacement and deformation data, failing to accurately reflect the development process of potential sliding surfaces and the dynamic evolution of slope stability under seepage. This invention provides an improved method based on monitoring the characteristic parameters of transparent soil particles. By observing the evolution of soil erosion under seepage using an image acquisition device and combining the acquired soil particle characteristic parameters, a potential sliding surface identification model based on seepage and a calculation method for a four-stage, three-threshold determination based on cracking-deformation-dynamic-slip are established. This method can more accurately capture the development and dynamic evolution of the sliding surface and achieve real-time monitoring of slope stability through threshold determination.

[0053] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A test device for the entire process of highway slope landslide, characterized in that, The device includes a water supply tank, a water collection tank, an upper water collection device, a rainfall device, a model box, a road surface cyclic load device, a drainage device, a simulated highway, a laser emission and optical projection device, and an image acquisition device. The water supply tank is connected to the rainfall device, the upper water collection device, and the simulated road to provide the mixed liquid; The water collection tank and the drainage device are connected to one side of the model box, and are used to collect and provide the discharged mixture, respectively. The upper water collection device and the rainfall device are located on the upper part of the model box, and are used to provide upper collection of mixed liquid and rainfall simulation, which is achieved by the mixed liquid; The simulated highway is set inside the model box and is equipped with a cyclic load device to provide cyclic loads for vehicles on the simulated highway. The laser emitting and optical projection device is located on the upper part of the simulated road inside the model box, and is used to form a speckle optical pattern. The image acquisition device is located directly in front of the outside of the model box and is used to record the test process. The mixture is formed by mixing white oil and n-dodecane.

2. The apparatus according to claim 1, characterized in that, The simulated highway includes bedrock fissure material, bedrock material, transparent soil slope material, and pavement material. The bedrock material is placed at the bottom of the model box, the transparent soil slope material is placed on the upper surface of the bedrock material, the pavement material is located above the transparent soil slope material, and the bedrock fissure material is placed inside the bedrock material.

3. The apparatus according to claim 2, characterized in that, It also includes rainwater supply pipelines, upper water collection and supply pipelines, bedrock fissure water supply pipelines, surface drainage pipelines, and groundwater drainage pipelines. One end of the rainwater supply pipeline is connected to the rainwater collection device, and the other end is connected to the water supply tank. One end of the upper water collection and supply pipeline is connected to the upper water collection device, and the other end is connected to the water supply tank. One end of the bedrock fissure water supply pipeline extends into a pre-designed internal channel of the bedrock material, forming an indirect connection with the bedrock fissure material through the channel, and the other end is connected to the water supply tank. One end of the surface drainage pipeline is connected to the drainage device, and the other end is connected to the water collection tank. One end of the groundwater drainage pipeline is connected to the bottom right side wall of the model box, and the other end is connected to the water collection tank.

4. The apparatus according to claim 1, characterized in that, The water supply tank includes a rainwater delivery pipe interface, a rainwater delivery control module, a rainwater delivery switch, a rainwater flow control valve, an upper water collection and delivery pipe interface, an upper water collection and delivery control module, an upper water collection and delivery switch, an upper water collection flow control valve, a bedrock fissure water delivery pipe interface, a bedrock fissure water delivery control module, a bedrock fissure water delivery switch, and a bedrock fissure water flow control valve. The rainwater delivery pipe interface connects to the rainwater supply pipeline, and the rainwater delivery control module controls the rainwater delivery switch to achieve rainwater delivery. The rainwater flow control valve... The upper water collection and delivery pipe interface is connected to the upper water collection and supply pipeline. The upper water collection and delivery control module controls the upper water collection and delivery switch to realize the upper water collection and delivery. The upper water collection flow control valve controls the amount of water transported from the upper water collection. The bedrock fissure water delivery pipe interface is connected to the bedrock fissure water supply pipeline. The bedrock fissure water delivery control module controls the bedrock fissure water delivery switch to realize the bedrock fissure water delivery. The bedrock fissure water control valve controls the amount of water transported from the bedrock fissure.

5. The apparatus according to claim 1, characterized in that, The water collection tank includes a surface drainage pipe interface, a surface drainage control module, a surface drainage switch, a surface drainage flow control valve, a groundwater drainage pipe interface, a groundwater drainage control module, a groundwater drainage switch, and a groundwater drainage flow control valve. The surface drainage pipe interface connects to the surface drainage pipeline, and the surface drainage control module controls the surface drainage switch to achieve surface drainage. The surface drainage flow control valve controls the amount of surface water collected. The groundwater drainage pipe interface connects to the groundwater drainage pipeline, and the groundwater drainage control module controls the groundwater drainage switch to achieve groundwater drainage. The groundwater drainage flow control valve controls the amount of groundwater collected.

6. The apparatus according to claim 1, characterized in that, The model box includes a box support and several model baffles; the model baffles are all made of transparent acrylic plastic sheets, and each model baffle is fixedly installed on the box support, and filter plates are provided on opposite sides inside the model box.

7. The apparatus according to claim 2, characterized in that, The bedrock fracture material is a mixture of paraffin solution and open-cell polyurethane foam in equal mass ratio.

8. The apparatus according to claim 6, characterized in that, The laser emitting and optical projection device is a laser projector. The laser bracket is fixed at the middle of the upper edge of the right-side filter partition and includes a horizontal fixing part and a vertical lifting part. The horizontal fixing part is connected to the filter partition, and the vertical lifting part is connected to the laser projector.

9. A test method for the entire process of highway slope landslide, characterized in that, The method is implemented using the apparatus described in any one of claims 1-8, and includes the following steps: S1. Assemble the model box, install all pipelines therein and lay filter baffles, road cyclic load device, drainage device, bedrock fissure material, bedrock material, transparent soil slope material, and road surface material; S2. After the static model box is stabilized, adjust the preset water supply flow rates of the upper water collection, rainfall and bedrock fissure water in the water supply tank, and set the initial hydrological conditions; S3. Adjust the preset drainage flow rates of surface drainage and groundwater drainage in the water collection tank, set the initial drainage conditions, and start the water collection tank; S4. Activate the laser projector to generate a speckle pattern on the surface of the slope composed of transparent soil material, and turn on the image acquisition device to prepare to record the movement of soil particles and the seepage process. S5. Activate the road surface cyclic loading device to apply vehicle loads of predetermined frequency and intensity to simulate highway traffic loads; S6. Start the water supply tank to supply water to the rainmaking device, the upper water collection device and the bedrock fissure material respectively, to simulate the process of natural rainfall, surface runoff injection and bedrock fissure water seepage; S7. During the test, the slope deformation and transparent soil test image information were continuously monitored and recorded using an image acquisition device to obtain soil particle movement characteristic parameters; S8. The test continues until a significant landslide occurs on the slope. Then all devices are stopped and the test is terminated. The changes in the simulated highway slope are determined based on the recorded monitoring data and the processed image feature parameters.

10. The method according to claim 9, characterized in that, The specific process of judging the changes in the simulated highway slope in S8 includes: S81. Determining the displacement velocity of the transparent soil slope based on the time interval between a certain video frame monitored, the displacement of the transparent soil slope during that time interval, and the time of the simulated highway landslide. S82. Calculate the soil loss volume, shear strain, and yield shear strain of the transparent soil slope. S83. If the shear strain is greater than or equal to the yield shear strain, then it is determined that there is a potential sliding surface in the transparent soil slope. S84. Divide the potential sliding surface into several points, and sum the distances between every two points to obtain the length of the potential sliding surface; S84. Determine the instantaneous safety factor of the slope based on the length of the potential sliding surface and its angle with the horizontal plane, the volume of soil loss and displacement velocity, and the acceleration due to gravity. S85. The instantaneous safety factor is compared with the set critical landslide coefficient to determine the deformation of the simulated highway slope.

Images