Device and method for measuring soil burst process on slope surface based on rock-soil interface depression

Abstract

The present application provides a device and method for measuring soil burst processes on slopes based on depressions at the rock-soil interface. The device comprises: a box body, the box body being tilted, a continuous concave support frame being provided at the bottom of the box body, a transparent glass plate being provided on one side of the box body, and a plurality of water outlets being provided on the downwardly tilted side of the box body; a slope control mechanism located at the bottom of the box body; a PIV system comprising a velocity measurement system and a laser emission system, the velocity measurement system being located on the side of the box body where the transparent glass plate is located; and a collection assembly being located on the downwardly tilted side of the box body. The present application is capable of accurately measuring the internal flow velocity during soil burst migration and conducting reliability research on the hydrological mechanism of sudden sudden changes in mountain torrents. It also simulates two components, surface runoff and soil burst, taking into account the soil-bedrock interface structure, and provides an economically feasible and scientifically rationally designed experimental method and procedure for the movement of fill-overflow water at rock-soil interfaces containing depression structures, especially the hydrological mechanism of the formation of super-large mountain torrent mudslides.

Description

Technical Field

[0001] The present application relates to the fields of hydrogeology, soil science and mountain torrent disaster technology, and in particular to a device and method for measuring flash flooding processes in soil on slopes based on rock-soil interface depressions. Background Art

[0002] Mountain slopes are often steep, widely graded, and highly permeable. Under heavy rainfall conditions, subsurface stormflow (SSF) hydrological processes primarily occur at and above the soil-bedrock interface. This is a special form of SSF in the aeration zone of steep slopes in hilly areas. It is ubiquitous in different climatic and geomorphic regions around the world and can contribute over 70% to the source of flash floods and debris flows. The depression structure and channels at the rock-soil interface profoundly influence the incubation, formation, and development of SSF, making it difficult to accurately characterize the hydrological conditions of the current flash flood-landslide-debris flow chain disaster, severely restricting the development and promotion of disaster hydrological driving theory and prevention technologies. At present, the understanding of the influence of the fill-overflow soil burst process and the internal seepage field on the runoff mutation effect under the influence of the rock-soil interface depression structure is based on the artificial rainfall slope runoff method that does not consider the rock-soil interface structure. This method mainly uses indoor conventional runoff plots to carry out controlled experimental research on runoff and sediment production under artificial rainfall conditions. However, it fails to fully consider the characteristics of the internal seepage field under wide-graded large-pore flow conditions and the hydrological nonlinear mutation process of soil burst. It also fails to fully consider the influence of the actual bedrock depression structure in the field on the initial mutation process and the subsidence process of runoff generation, which limits the accurate measurement and understanding of the soil burst process. At the same time, isotope / hydrochemical tracer runoff segmentation methods are often used, such as water isotopes (δD, δ18O), hydrochemistry (electrical conductivity EC, Cl-) and other tracers, to conduct research on water source paths and water source contributions at the watershed scale or slope scale, and to separate the contributions of different water sources such as precipitation, intersoil flow, and groundwater. However, they cannot quantify the migration and flow processes within the soil or at the interface, and fail to well characterize the hydrophysical processes of the formation of mountain torrents, debris flows and landslides, which limits the development of hydrologically driven disaster theories. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a device and method for measuring flash flow processes in slope soil based on rock-soil interface depressions, so as to solve the problem that the existing technology cannot quantify the migration and flow processes inside the soil or at the interface.

[0004] In a first aspect, the present application provides a device for measuring a flooding process in soil on a slope surface based on a rock-soil interface depression, comprising: a box body, the box body being arranged at an angle, a continuous concave support frame being provided at the bottom of the box body, a transparent glass plate being provided on one side of the box body, and a plurality of water outlet holes being provided on the downwardly inclined side of the box body;

[0005] A slope control mechanism is located at the bottom of the box;

[0006] The PIV system includes a speed measurement system and a laser emission system. The speed measurement system is located on the side of the box where the transparent glass plate is located; the laser emission system is located on the side of the box;

[0007] The collecting assembly is located on the downwardly inclined side of the box body.

[0008] In one embodiment, the diameter of the water outlet is 0.3 cm to 0.6 cm; and / or

[0009] The inclination of the box is 0 degrees to 50 degrees.

[0010] In one embodiment, the continuous concave support frame includes a support frame, the support frame having a first end and a second end, and a plurality of rectangular depression grooves are provided on the support frame along the direction from the first end to the second end, each of the rectangular depression grooves is provided with a U-shaped liner, the plurality of rectangular depression grooves and the U-shaped liner in each of the rectangular depression grooves form a depression structure, and the upper part of the support frame on both sides of the U-shaped liner in each of the rectangular depression grooves is a non-depression structure; and / or

[0011] The grade control mechanism includes a support box, a first heavy-duty hinge being provided between the support box near the second end and the box body, a hydraulic lift being provided at the bottom of the support box near the first end, the hydraulic lift extending to the outside of the support box, the top support of the hydraulic lift being connected to the box body via a second heavy-duty hinge; and / or

[0012] The speed measurement system includes: a high-speed camera and an image analyzer, wherein the high-speed camera is located on the side of the box where the transparent glass plate is located; and / or

[0013] The laser emission system comprises: a laser and a light guide arm connected to the laser; and / or

[0014] The collection assembly includes a bottom soil flow collection trough, a middle soil flow collection trough and a surface runoff collection trough, which are located on the downwardly inclined side of the box body and are arranged in sequence from bottom to top. The bottom soil flow collection trough, the middle soil flow collection trough and the surface runoff collection trough are all connected to the collecting barrel through a water pipe.

[0015] In one embodiment, the second end is larger than the first end; and / or

[0016] Each of the U-shaped lining plates is provided with overlapping edges at both ends thereof; and / or

[0017] Along the direction from the first end to the second end, the continuous concave support frame is provided with a plurality of vertical support plates; and / or

[0018] A detachable cover is provided on the upper portion of each rectangular depression; and / or

[0019] The U-shaped liner includes an arc portion at the bottom and vertical portions on both sides of the arc portion. The radius of the arc portion is R, the slope of the continuous concave support frame soil is θ, and b is the box width. The volume V of the arc portion is 圆弧 for:

[0020] V 圆弧 =R²×b[π / 2-θ-(sin2θ) / 2]

[0021] According to the soil slope of the continuous concave support frame θ and the depth of the U-shaped liner ℎ, the volume V of the diamond part of the U-shaped liner is obtained 菱形 :

[0022] V 菱形 =2R×h×b×cos²θ

[0023] According to the soil slope of the continuous concave support frame as θ, the radius of the arc as R and the depth of the U-shaped liner as ℎ, the volume of the depression enclosed by the U-shaped liner and the interior of the box is obtained:

[0024] V=2R×h×b×cos²θ+R²×b[π / 2-θ-(sin2θ) / 2]; and / or

[0025] The bottom of the support box is provided with universal wheels, which facilitate the movement of the box; and / or

[0026] The bottom mid-soil flow collection trough, the middle mid-soil flow collection trough and the surface runoff collection trough all include a triangular plate located on the downward-inclined side of the box body, one side of the triangular plate is fixed to the downward-inclined side of the box body, and the other two sides of the triangular plate are provided with baffles. The end of the triangular plate away from the downward-inclined side of the box body is connected to the water pipe, and a flow meter is connected to the collecting barrel.

[0027] In a second aspect, the present application provides an experimental method for measuring a flooding process in soil on a slope based on a rock-soil interface depression, comprising the following steps:

[0028] Providing transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3;

[0029] Fill the box with transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3 from bottom to top;

[0030] Adjust the cabinet to an inclined angle;

[0031] Set the rainfall intensity, turn on the velocity measurement system and laser emission system after the rainfall begins, and collect flow samples through the collection component at the same time.

[0032] In one embodiment, the first type of transparent soil and the fourth type of transparent soil are mixed at a mass ratio of 1:4, 1:2 and 1:1 respectively to obtain transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3; and / or

[0033] The thickness of the transparent soil sample T1 is 10 cm, the thickness of the transparent soil sample T2 is 10 cm, and the thickness of the transparent soil sample T3 is 20 cm; and / or

[0034] The rainfall intensity is set to seven gradient rainfalls of 5mm / h, 10mm / h, 30mm / h, 60mm / h, 90mm / h, 120mm / h and 150mm / h. The duration of each gradient rainfall is 45 minutes. The flow meters connected to the mid-flow collection trough at the bottom of the box, the mid-flow collection trough in the middle and the surface runoff collection trough automatically collect the flow rate every 1 minute. After each rainfall, the next rainfall will be carried out after a 30-minute pause or 3-5 days of suspension.

[0035] In one embodiment, a method for obtaining the first type of transparent soil includes:

[0036] The fused quartz sand was sieved into 0~1mm, 1~2mm, 2~3mm, 3~5mm, 5~8mm, 8~10mm, 10~20mm and 20~40mm;

[0037] Mix 0-1 mm and 1-2 mm in a mass ratio of 1:1 to obtain 0-2 mm fused quartz sand;

[0038] Add pore fluid into 0-2 mm fused quartz sand so that the pore fluid uniformly wets the surface of the 0-2 mm fused quartz sand to form sample a;

[0039] Place sample a in a vacuum environment and exhaust for 6 hours to 10 hours to obtain sample b;

[0040] In a vacuum environment, continue to add pore fluid to sample b while continuing to evacuate until the liquid level of the pore fluid submerges the upper surface of sample b, forming sample c;

[0041] Remove sample c from the vacuum environment and allow it to stand at room temperature for 12 to 16 hours to form sample d, i.e., the first type of transparent soil; and / or

[0042] The method for obtaining the second type of transparent soil comprises: mixing fused quartz sands of 2-3 mm, 3-5 mm, 5-8 mm, and 8-10 mm in a mass ratio of 1:1:1:1 to obtain fused quartz sands of 2-10 mm; the remaining steps are the same as those of the method for preparing the first type of transparent soil; and / or

[0043] The method for obtaining the third type of transparent soil includes: mixing 10-20 mm and 20-40 mm fused quartz sand in a mass ratio of 1:1 to obtain 10-40 mm fused quartz sand; the remaining steps are the same as the method for preparing the first type of transparent soil.

[0044] In one embodiment, the pore fluid includes n-dodecane and No. 15 white oil, and the mass ratio of n-dodecane to No. 15 white oil is 1:4. After the preparation is completed, Nile red dye is added until the pore fluid is completely colored; and / or

[0045] The second type of transparent soil and the third type of transparent soil are mixed in a mass ratio of 1:1 to obtain the fourth type of transparent soil.

[0046] In one embodiment, the transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3 are backfilled at the top, middle and bottom of the slope in the box, and multiple soil moisture monitoring probes and matrix suction probes are provided at the edge and center of the U-shaped liner.

[0047] In one embodiment, before rainfall begins, the laser emission system and the velocity measurement system are turned on, and the planar laser emitted by the laser and the light-guiding arm slices the transparent soil sample T1 and / or transparent soil sample T2 and / or transparent soil sample T3 in the box to form laser speckles, ensuring that the laser beam can uniformly illuminate the cross-section of the seepage field of the transparent soil sample T1 and / or transparent soil sample T2 and / or transparent soil sample T3 in the depression structure area and the non-depression structure area; the high-speed camera is used to record the laser speckles, and the image analyzer is used to analyze the laser speckles. The high-speed camera and the image analyzer cooperate with each other to capture the detailed flow velocity distribution density, size and direction of the soil flow around the U-shaped liner at the bottom of the box during the entire rainfall process.

[0048] The present application provides a device for measuring soil burst processes on slopes taking into account the depression structure at the rock-soil interface. The continuous concave support frame at the bottom can adjust the volume, depth and position to restore the real rock-soil interface depression structure to the greatest extent. Moreover, the PIV system on the side assists in real-time observation of the migration and diffusion process of the filling-overflow seepage field (flow velocity and flow direction) of the rock-soil interface depression structure, and can accurately characterize the near-saturated dynamic process of the rock-soil interface filling-overflow hydrological mechanism at the moment of sudden change in production and sand production, and depict the production process of wide-graded and high-permeability slopes in mountainous areas more realistically and reasonably.

[0049] This application mainly uses transparent test soil to study the migration and change process of flow velocity, direction and density of soil flash flood in the depression structure area at the internal rock-soil interface, and compares the flow rate at the moment of sudden flow generation in the collecting trough, which helps to more accurately decompose the dynamic contribution of surface runoff and soil flash flood in the sudden flow generation process of flash flood, and can improve the accuracy and reliability of the hydrological simulation of flash flood in the basin from a mechanistic perspective.

[0050] The soil burst method and experimental results of this application can provide key hydrological parameters for the simulation of mountain hydrological processes, shallow landslides and debris flow formation processes, and can form a key hydrological theory for studying the formation of complex chain disasters such as mountain torrents, landslides and debris flows in wide-graded and high-permeability soil basins in hilly and mountainous areas, thereby promoting the development of the theoretical system of mountain torrent and debris flow disasters and the deepening of disaster reduction principles. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings of the embodiments. Obviously, the drawings described below only relate to some embodiments of the present application and are not intended to limit the present application.

[0052] Figure 1 This is a schematic diagram of the structure of a device for measuring a flooding process in soil on a slope based on a rock-soil interface depression according to an embodiment of the present application;

[0053] Figure 2 This is a schematic structural diagram of a continuous concave support frame according to an embodiment of the present application;

[0054] Figure 3 This is a nonlinear behavior diagram of flooding mutation caused by a flash flow process in soil at a certain slope in an embodiment of the present application.

[0055] Description of reference numerals:

[0056] 1- box body, 2- continuous concave support frame, 21- U-shaped lining plate, 22- rectangular depression trough, 23- support plate, 24- cover plate, 3- transparent glass plate, 41- high-speed camera, 42- image analyzer, 51- bottom soil midflow collection trough, 52- middle soil midflow collection trough, 53- surface runoff collection trough, 54- triangular plate, 55- water pipe, 56- collecting barrel, 61- support box, 62- hydraulic lift, 63- universal wheel, 71- laser, 72- light guide arm. DETAILED DESCRIPTION

[0057] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of this application.

[0058] In the description of the present application, it should be understood that the terms "length", "width", "thickness", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a unique orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0059] In the application, the word "exemplary" is used to mean "serving as an example, illustration, or description." Any embodiment described in this application as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is given to enable any person skilled in the art to implement and use the present application. In the following description, details are listed for the purpose of explanation. It should be understood that one of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other instances, known structures and processes are not described in detail to avoid obscuring the description of the present application with unnecessary detail. Therefore, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles disclosed herein.

[0060] First, see Figure 1 and Figure 2 The present invention provides a device for measuring a flooding process in soil on a slope based on a rock-soil interface depression, comprising:

[0061] The box body 1 is tilted, a continuous concave support frame 2 is provided at the bottom of the box body 1, one side of the box body 1 is a transparent glass plate 3, and a plurality of water outlet holes are provided on the downwardly tilted side of the box body 1;

[0062] A slope control mechanism is located at the bottom of the box 1;

[0063] The PIV system includes a speed measurement system and a laser emission system. The speed measurement system is located on the side of the box 1 where the transparent glass plate 3 is located; the laser emission system is located on the side of the box 1;

[0064] The collecting assembly is located on the downwardly inclined side of the box body 1.

[0065] The present application provides a device for measuring the flash flow process in soil on a slope surface taking into account the depression structure at the rock-soil interface. The continuous concave support frame 2 at the bottom can adjust the volume, depth and position to restore the real rock-soil interface depression structure to the greatest extent. Moreover, the PIV system on the side assists in real-time observation of the migration and diffusion process of the filling-overflow seepage field (flow velocity and flow direction) of the rock-soil interface depression structure, and can accurately characterize the near-saturated dynamic process of the filling-overflow hydrological mechanism of the rock-soil interface at the moment of sudden change in production and sand production, and depict the production process of wide-graded and high-permeability slopes in mountainous areas more realistically and reasonably.

[0066] This application mainly uses transparent test soil to study the migration and change process of flow velocity, direction and density of soil flash flood in the depression structure area at the internal rock-soil interface, and compares the flow rate at the moment of sudden flow generation in the collecting trough, which helps to more accurately decompose the dynamic contribution of surface runoff and soil flash flood in the sudden flow generation process of flash flood, and can improve the accuracy and reliability of the hydrological simulation of flash flood in the basin from a mechanistic perspective.

[0067] The soil burst method and experimental results of this application can provide key hydrological parameters for the simulation of mountain hydrological processes, shallow landslides and debris flow formation processes, and can form a key hydrological theory for studying the formation of complex chain disasters such as mountain torrents, landslides and debris flows in wide-graded and high-permeability soil basins in hilly and mountainous areas, thereby promoting the development of the theoretical system of mountain torrent and debris flow disasters and the deepening of disaster reduction principles.

[0068] This application utilizes a soil burst process measurement device based on a rock-soil interface depression on a slope surface, which can accurately measure the internal flow velocity during soil burst migration and study the reliability of the hydrological mechanism of the sudden change process of mountain torrents. At the same time, it simulates the two components of surface runoff and soil burst considering the soil-bedrock interface structure, and provides an economically feasible and scientifically designed experimental method and steps for the hydrological mechanism of the filling-overflow water movement at the rock-soil interface containing a depression structure, especially the formation of super-large mountain torrent mudslides.

[0069] This application achieves the quantitative characterization of the migration and extension seepage field of flash flood in the fill-overflow soil at the rock-soil interface of wide-graded and high-permeability slopes, reveals the intrinsic hydrological mechanism of the sudden change in rainfall runoff, and can improve the simulation of the nonlinear process of flood mutation from the perspective of runoff mechanism, making it more scientific and realistic.

[0070] This application can carry out indoor artificial rainfall slope runoff model tests, use high-definition image analysis technology to process static pictures and dynamic videos, obtain data such as seepage path, seepage velocity, and near-saturated horizontal migration flux in the depression structure area of ​​the bedrock interface, reproduce the entire process of rainfall infiltration, soil flow abortion and landslide deformation initiation, realize visual observation of seepage and deformation inside transparent soil, and analyze the hysteresis effect of the depression filling-overflow process on the small amount of runoff production at the initial stage of rainfall and the flood receding process after the rainfall stops.

[0071] This application uses transparent soil technology to allow direct observation of processes such as seepage, erosion, and deformation within the soil, enabling researchers to intuitively understand the physical processes within the soil. Experiments can also be conducted using real soil in the field, as needed.

[0072] It can be understood that the bottom of the continuous concave support frame 2 is consistent with the bottom of the box body 1, and vaseline is applied to the connection gap between the box body 11 and the continuous concave support frame 2 for sealing to reduce the boundary effect.

[0073] It can be understood that the box body 1 is in the shape of a rectangular parallelepiped, and the slope control structure at the bottom of the box body 1 is used to control the inclination of the box body 1.

[0074] In some embodiments, the diameter of the water outlet is 0.3 cm to 0.6 cm, for example, it can be 0.3 cm, 0.4 cm, 0.5 cm, 0.6 cm, etc.

[0075] For example, the downwardly inclined side of the box body 1 is provided with 12 drainage holes, each with 20 drainage holes, for a total of 240 drainage holes, each with a diameter of 0.5 cm, and the area of ​​the box body 1 on the side where the drainage holes are located is 0.3 m2.

[0076] In some embodiments, the inclination of the box body 1 is 0 degrees to 50 degrees, for example, it can be 0 degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, etc.

[0077] Exemplarily, the inclination of the box body 1 is 35 degrees.

[0078] Exemplarily, the box body 1 is in a square shape, for example, a rectangular parallelepiped or a cube shape.

[0079] In some embodiments, the continuous concave support frame 2 includes a support frame having a first end and a second end. Along the direction from the first end to the second end, a plurality of rectangular depression grooves 22 are provided on the support frame, and a U-shaped lining 21 is provided in each of the rectangular depression grooves 22. The plurality of rectangular depression grooves 22 and the U-shaped lining 21 in each of the rectangular depression grooves 22 form a depression structure, and the upper part of the support frame on both sides of the U-shaped lining 21 in each of the rectangular depression grooves 22 is a non-depression structure.

[0080] It can be understood that the multiple rectangular depression grooves 22 on the support frame and the U-shaped lining plate 21 provided in each of the rectangular depression grooves 22 are imitation depression structures.

[0081] Furthermore, the second end is larger than the first end.

[0082] Furthermore, both ends of each U-shaped liner 21 are provided with overlapping edges facing outwards.

[0083] Furthermore, along the direction from the first end to the second end, the continuous concave support frame 2 is provided with a plurality of vertical support plates 23 .

[0084] It can be understood that the vertical support plates 23 are located between adjacent rectangular depressions 22 .

[0085] It can be understood that the continuous concave support frame 2 is equivalent to the bedrock layer.

[0086] Furthermore, a removable cover plate 24 is provided above each rectangular depression 22. It is understood that the cover plate 24 is a rectangular acrylic plate. When the depression structure of the bedrock layer in nature is relatively simple and is only located at the bottom of the slope, the cover plate 24 can be used to enclose the rectangular depressions 22 at the top and middle of the continuous concave support frame 2. Similarly, when located in the middle or top of the slope, the cover plate 24 can be used to enclose the remaining two rectangular depressions 22.

[0087] For example, the length×width×height of the rectangular acrylic plate is 500 mm×140 mm×2 mm, and the overlapping portion of the cover plate 24 and the continuous concave support frame 2 is sealed with glass glue.

[0088] When a certain rectangular depression groove 22 is not needed, the corresponding unnecessary rectangular depression groove 22 is covered with a cover plate 24 , and the four sides of the cover plate 24 are sealed with glass glue.

[0089] Exemplarily, the continuous concave support frame 2 is made of six acrylic plates, and the acrylic plates on both sides are right-angled trapezoids with one end small and the other end large. The upper base of the right-angled trapezoid is 65 mm, and the lower base is 130 mm. The bottom acrylic plate is a rectangle with a length of 980 mm and a width of 500 mm. The upper part and both ends are then closed to form a continuous concave support frame 2; three rectangular depressions 22 are opened on the support frame, and each rectangular depression 22 is provided with a U-shaped lining plate 21, which is glued to both sides of the upper part of the continuous concave support frame 2 by overlapping and glass glue.

[0090] It can be understood that the rectangular depression groove 22 can also be reserved in advance when the continuous concave support frame 2 is manufactured.

[0091] For example, the width of the U-shaped lining plate 21 can be 15 cm, 20 cm or 30 cm. It is understood that the number of the corresponding rectangular depression groove 22 U-shaped lining plates 21 can be adjusted and reduced according to the situation.

[0092] Furthermore, the U-shaped liner 21 includes an arc portion at the bottom and vertical portions on both sides of the arc portion. The radius of the arc portion is R, and the soil slope of the continuous concave support frame 2 is θ. The volume V of the arc portion is 圆弧 for:

[0093] V 圆弧=R²×b[π / 2-θ-(sin2θ) / 2]

[0094] According to the soil slope of the continuous concave support frame 2 as θ and the depth ℎ of the U-shaped liner 21, the volume V of the diamond part of the U-shaped liner 21 is obtained. 菱形 :

[0095] V 菱形 =2R×h×b×cos²θ

[0096] According to the soil slope of the continuous concave support frame 2 as θ, the radius of the arc part as R and the depth ℎ of the U-shaped liner 21, the volume of the depression enclosed by the U-shaped liner 21 and the interior of the box 1 is obtained:

[0097] V=2R×h×b×cos²θ+R²×b[π / 2-θ-(sin2θ) / 2].

[0098] In some embodiments, the slope control mechanism includes a support box 61, a first heavy-duty hinge is provided between the support box 61 near the second end and the box body 1, a hydraulic lift 62 is provided at the bottom of the support box 61 near the first end, the hydraulic lift 62 extends to the outside of the support box 61, and the top support of the hydraulic lift 62 is connected to the box body 1 through a second heavy-duty hinge.

[0099] Furthermore, universal wheels 63 are provided at the bottom of the support box 61 , and the provision of the universal wheels 63 facilitates the movement of the box body 1 .

[0100] It can be understood that the box body 1 can rotate around the first heavy hinge; the slope of the box body 1 can be changed by adjusting the lifting and lowering of the hydraulic lift 62 support.

[0101] In some embodiments, the speed measurement system includes: a high-speed camera 41 and an image analyzer 42 , wherein the high-speed camera 41 is located on a side of the box 1 where the transparent glass plate 3 is located.

[0102] In some embodiments, the laser emission system includes: a laser 71 and a light-guiding arm 72 connected to the laser 71 .

[0103] It can be understood that the laser source emits a sheet laser beam to illuminate a section of the flow field in the box 1. The tracer particles added to the flow field scatter the laser, so that the laser can be scattered to the side of the flow field. A high-speed camera 41 is set in a direction perpendicular to the illuminated section to continuously capture the behavior of the illuminated flow field at a set time interval, and then transmit the data to the computer. The computer then processes the data according to the set program and algorithm to obtain the speed and density information of the flow field.

[0104] As can be understood, the high-speed camera 41 is used to record laser speckle patterns, and the image analyzer is used to analyze them. PIV technology can capture the detailed velocity distribution, flow characteristics, and average velocity of subsurface flow, including its magnitude and direction. This is crucial for understanding the dynamic and sudden change behavior of subsurface flow under different hydraulic gradients, its contribution to peak flash flood discharge, and the mechanism of landslide initiation.

[0105] It can be understood that under rainfall conditions, by arranging the laser emission system on the side of the box 1, it is ensured that the laser beam can evenly illuminate the cross-section of the transparent soil seepage field in the U-shaped liner 21 area (i.e., the depression structure area) and the smooth area of ​​the support plates 23 on both sides of the U-shaped liner 21 area (i.e., the non-depression structure area).

[0106] It can be understood that the laser 71 and the light-guiding arm 72 are used to emit planar laser light to perform layer-cutting on the transparent soil in the box 1 to form laser speckles.

[0107] Exemplarily, the light guide arm 72 uses a Powell prism, model KS-PB10A30-D6. The Powell prism is an optical marking prism that allows the laser beam to be optimally marked into a straight line with uniform optical density, good stability, and good linearity after passing through. The Powell prism marking is superior to the marking mode of the cylindrical lens, and can eliminate the central hot spot and faded edge distribution of the Gaussian beam. The incident diameter is 5mm and the fan angle is 30°. The laser 71, model MW-GL-532 / 1~500mW, is a solid laser 71 that can emit green light with a wavelength of 532nm.

[0108] In some embodiments, the collection assembly includes a bottom soil mid-flow collection trough 51, a middle soil mid-flow collection trough 52 and a surface runoff collection trough 53 located on the downwardly inclined side of the box body 1 and arranged in sequence from bottom to top. The bottom soil mid-flow collection trough 51, the middle soil mid-flow collection trough 52 and the surface runoff collection trough 53 are all connected to a collecting barrel 56 through a water pipe 55.

[0109] Furthermore, the bottom soil midflow collection trough 51, the middle soil midflow collection trough 52 and the surface runoff collection trough 53 all include a triangular plate 54 located on the downwardly inclined side of the box body 1, one side of the triangular plate 54 is fixed to the downwardly inclined side of the box body 1, and the other two sides of the triangular plate 54 are provided with baffles. The end of the triangular plate 54 away from the downwardly inclined side of the box body 1 is connected to the water pipe 55, and the collecting barrel 56 is connected to a flow meter.

[0110] It can be understood that the flow meter can monitor the flow rate of soil burst in real time.

[0111] Illustratively, the height of the baffle is 2 cm to prevent overflow; the distances between the bottom soil midflow collection trough 51, the middle soil midflow collection trough 52 and the surface runoff collection trough 53 and the bottom of the box 1 are 10 cm, 25 cm and 40 cm respectively; the bottom of the surface runoff collection trough 53 is flush with the surface of the transparent sample soil T3 filled in the box 1; the bottom of the middle soil midflow collection trough 52 is 15 cm away from the surface of the transparent sample soil T1; and the bottom of the bottom soil midflow collection trough 51 is 10 cm away from the bottom of the box 1.

[0112] In a second aspect, an embodiment of the present application provides an experimental method for measuring a flooding process in soil on a slope based on a rock-soil interface depression, comprising the following steps:

[0113] S01. Provide transparent soil sample T1, transparent soil sample T2 and transparent soil sample T3;

[0114] S02, filling the box 1 with transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3 from bottom to top;

[0115] S03, adjusting the box 1 to an inclined angle;

[0116] S04. Set the rainfall intensity, start the speed measurement system and the laser emission system after the rainfall starts, and collect flow samples through the collection component at the same time.

[0117] In the S01:

[0118] In some embodiments, the first type of transparent soil and the fourth type of transparent soil are mixed at mass ratios of 1:4, 1:2 and 1:1, respectively, to obtain transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3.

[0119] Furthermore, the method for obtaining the first type of transparent soil includes:

[0120] S011. Sieve the fused quartz sand into 0~1mm, 1~2mm, 2~3mm, 3~5mm, 5~8mm, 8~10mm, 10~20mm and 20~40mm;

[0121] S012, mixing 0-1 mm and 1-2 mm in a mass ratio of 1:1 to obtain 0-2 mm fused quartz sand;

[0122] S013. Add pore fluid to 0-2 mm fused quartz sand so that the pore fluid uniformly wets the surface of the 0-2 mm fused quartz sand to form sample a;

[0123] It can be understood that at this time, the amount of pore fluid added to sample a should be based on the ability to wet all the transparent soil raw materials, and should not be too much to avoid affecting the subsequent exhaust effect.

[0124] S014. Place sample a in a vacuum environment and exhaust for 6 hours to 10 hours to obtain sample b;

[0125] It can be understood that the sample a is placed in a vacuum environment and evacuated for 6 hours to 10 hours, for example, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, etc.

[0126] For example, sample A was placed in a vacuum chamber, the vacuum pump was turned on, and the vacuum was evacuated for 8 hours. This was done to expel air adsorbed within and on the surface of sample A (the transparent soil), reducing the generation of bubbles and allowing for better integration of sample A (the transparent soil) with the pore fluid, resulting in sample B. During the evacuation process, sample A gradually became transparent, while sample B took on a light white color.

[0127] S015. In the vacuum environment, continue to add pore fluid to sample b while continuing to evacuate until the liquid level of the pore fluid submerges the upper surface of sample b, thereby forming sample c.

[0128] It can be understood that at this time, sample c is translucent and contains a large number of bubbles. The pore fluid has completely immersed the molten quartz sand, and the pores inside the transparent soil raw material are filled with the pore fluid.

[0129] S016. Remove sample c from the vacuum environment and allow it to stand at room temperature for 12 to 16 hours to form sample d, i.e., the first type of transparent soil.

[0130] It can be understood that the time of standing at room temperature for 12 hours to 16 hours can be, for example, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, etc.

[0131] It can be understood that at this time, the bubbles in the pore fluid will gradually escape, and the transparent soil raw material will further combine with the pore fluid to eventually form transparent soil, that is, sample d is transparent, the transparent soil raw material and the pore fluid are evenly mixed, there are no obvious bubbles, and it has good light transmittance and uniformity. The prepared sample d is placed in a constant temperature environment and sealed for preservation.

[0132] In said S013:

[0133] In some embodiments, the pore fluid includes n-dodecane and No. 15 white oil, and the mass ratio of n-dodecane to No. 15 white oil is 1:4. After the preparation is completed, Nile red dye is added until the pore fluid is completely colored.

[0134] In some embodiments, the method for obtaining the second type of transparent soil includes: mixing 2~3mm, 3~5mm, 5~8mm, and 8~10mm fused quartz sand in a mass ratio of 1:1:1:1 to obtain 2~10mm fused quartz sand; the remaining steps are the same as the method for preparing the first type of transparent soil.

[0135] In some embodiments, the method for obtaining the third type of transparent soil includes: mixing 10-20 mm and 20-40 mm fused quartz sand in a mass ratio of 1:1 to obtain 10-40 mm fused quartz sand; the remaining steps are the same as the method for preparing the first type of transparent soil.

[0136] Furthermore, the second type of transparent soil and the third type of transparent soil are mixed in a mass ratio of 1:1 to obtain the fourth type of transparent soil.

[0137] It can be understood that the first type of transparent soil is the soil part in the simulated slope soil; the second type of transparent soil is the small gravel part in the simulated slope soil; the third type of transparent soil is the medium gravel part in the simulated slope soil; and the fourth type of transparent soil is the stone part in the simulated slope soil.

[0138] For example, first fill the box 1 with a transparent soil sample T1 as a bottom layer, with a thickness of 10 cm. Use a small shovel to shovel the transparent soil sample T1 into the U-shaped liner 21 on the rectangular depression 22. First, fill the bottom of the U-shaped liner 21 completely. Use a scraper to gently scrape the surface of the transparent soil sample T1 on the U-shaped liner 21, remove any excess transparent soil sample T1, and align the surface of the transparent soil sample T1 with the upper edge of the U-shaped liner 21. Then, gradually fill upwards by 10 cm. During the filling process, ensure that the transparent soil is evenly distributed to avoid localized accumulation or voids. After each 5 cm thick layer, gently tap it with a wooden mallet to compact the soil layer, but avoid over-compacting to avoid damaging the transparent soil structure. Continue filling the transparent soil sample T1 to a depth of 10 cm. Then, add a second layer of transparent soil sample T2 on top of the bottom layer of transparent soil sample T1, with a thickness of 15 cm. Finally, add a second layer of transparent soil sample T3 on top of the surface of the second layer of transparent soil sample T2, with a thickness of 15 cm. After filling each layer of transparent sample soil, tap it gently with a wooden hammer to ensure that the soil layer is dense.

[0139] It can be understood that after the surface of the transparent soil sample T1 is flush with the upper edge of the U-shaped liner 21 and then filled upward by 10 cm, the thickness of the transparent soil sample T1 is 10 cm.

[0140] In some embodiments, the top, middle and bottom of the slope of transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3 are backfilled in the box 1, and multiple soil moisture monitoring probes and matrix suction probes are provided on the edge and center of the U-shaped liner 21.

[0141] As you can understand, the goal is to continuously record the continuous changes and mutations in soil moisture content at each monitoring location during the migration and diffusion of the floodwater within the soil. The vertical spacing between any two probes is 10 cm, and the horizontal spacing is greater than 10 cm to minimize the mutual influence between sensors when collecting data.

[0142] In said S04:

[0143] In some embodiments, the rainfall intensity is set to seven gradient rainfalls of 5mm / h, 10mm / h, 30mm / h, 60mm / h, 90mm / h, 120mm / h and 150mm / h, and the duration of each gradient rainfall is 45 minutes. The flow meters connected to the mid-flow collection trough 51 at the bottom of the box 1, the mid-flow collection trough 52 in the middle and the surface runoff collection trough 53 automatically collect the flow rate every 1 minute. After each rainfall, the next rainfall will be carried out after a pause of 30 minutes or 3-5 days.

[0144] Furthermore, before the start of rainfall, the laser emission system and the speed measurement system are turned on, and the planar laser emitted by the laser 71 and the light-guiding arm 72 performs layer-cutting on the transparent soil sample T1 and / or transparent soil sample T2 and / or transparent soil sample T3 in the box 1 to form laser speckles, ensuring that the laser beam can evenly illuminate the cross-section of the seepage field of the transparent soil sample T1 and / or transparent soil sample T2 and / or transparent soil sample T3 in the depression structure area and the non-depression structure area; the high-speed camera 41 is used to record the laser speckles, and the image analyzer is used to analyze the laser speckles. The high-speed camera 41 and the image analyzer cooperate with each other to capture the detailed flow velocity distribution density, size and direction of the soil flow around the U-shaped liner 21 at the bottom of the box 1 during the entire rainfall process.

[0145] For example, see Figure 3 This application mainly provides the nonlinear behavior of sudden flooding caused by the soil flash flow process under a certain slope, including:

[0146] The top, middle and bottom of the slope of transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3 are backfilled in the box 1, and multiple soil moisture monitoring probes and matrix suction probes are set at the edge and center of the U-shaped liner 21.

[0147] As you can understand, the purpose of this is to continuously record the continuous changes and mutations in soil moisture content at each monitoring location during the migration and diffusion of floodwater within the soil. The vertical spacing between any two probes is 10 cm, the vertical spacing is 10 cm, and the horizontal spacing is greater than 10 cm to reduce the mutual influence between sensors when collecting data. The initial soil water storage capacity (DASI) is the weighted average of the initial volumetric water content measured by soil moisture monitoring probes at different layers before runoff occurs:

[0148] ;

[0149] Where DASI is the soil water storage capacity before the runoff event, i is the number of different transparent soil vertical layers, n is the total number of transparent soil layers during the transparent soil observation, θ i is the average volumetric water content between the i-th layer and the i-1-th layer of transparent soil, D iis the depth of the i-th soil profile, D i-1 is the depth of the i-1th soil profile.

[0150] Furthermore, the rainfall of the experimental sessions was superimposed with the soil water storage capacity before the runoff event;

[0151] It can be understood that by entering the collected rainfall amount + the superposition value of the soil water storage capacity before the runoff event and the collection trough flow data into the computer to make a scatter plot, we can intuitively understand the flow production and flow surge process of the bottom soil midflow collection trough 51, the middle soil midflow collection trough 52 and the surface runoff collection trough 53 during the entire rainfall process.

[0152] Furthermore, by combining the Macquart method and the global optimization method, a nonlinear response relationship function of the sum of the experimental rainfall and the soil water storage capacity before the runoff event to the runoff was obtained, which quantitatively understood the nonlinear behavior of flood mutation caused by the soil flash flow process under a certain slope.

[0153] The basic concepts have been described above. It will be apparent to those skilled in the art that the detailed disclosure above is merely illustrative and does not limit the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to the present application. Such modifications, improvements, and amendments are suggested in the present application and remain within the spirit and scope of the exemplary embodiments of the present application.

[0154] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

Claims

1. A device for measuring soil flooding in slopes based on rock-soil interface depressions, characterized in that: include: The box body is tilted, a continuous concave support frame is provided at the bottom of the box body, one side of the box body is a transparent glass plate, and a plurality of water outlet holes are provided on the downwardly tilted side of the box body; A slope control mechanism is located at the bottom of the box; The PIV system includes a speed measurement system and a laser emission system. The speed measurement system is located on the side of the box where the transparent glass plate is located; the laser emission system is located on the side of the box; A collecting assembly is located on a downwardly inclined side of the box; The continuous concave support frame includes a support frame, which has a first end and a second end. Along the direction from the first end to the second end, a plurality of rectangular depression grooves are arranged on the support frame, and a U-shaped lining is arranged in each of the rectangular depression grooves. The plurality of rectangular depression grooves and the U-shaped lining in each of the rectangular depression grooves form a depression structure, and the upper part of the support frame on both sides of the U-shaped lining in each of the rectangular depression grooves is a non-depression structure.

2. The device for measuring flooding process in soil on a slope based on a rock-soil interface depression according to claim 1 is characterized in that: The diameter of the water outlet is 0.3cm~0.6cm; and / or The inclination of the box is 0 degrees to 50 degrees.

3. The device for measuring flooding process in soil on a slope based on a rock-soil interface depression according to claim 1, characterized in that: The grade control mechanism includes a support box, a first heavy-duty hinge disposed between the support box near the second end and the box body, a hydraulic lift disposed at the bottom of the support box near the first end, the hydraulic lift extending to the outside of the support box, and a top support of the hydraulic lift connected to the box body via a second heavy-duty hinge; and / or The speed measurement system includes: a high-speed camera and an image analyzer, wherein the high-speed camera is located on the side of the box where the transparent glass plate is located; and / or The laser emission system comprises: a laser and a light guide arm connected to the laser; and / or The collection assembly includes a bottom soil flow collection trough, a middle soil flow collection trough and a surface runoff collection trough, which are located on the downwardly inclined side of the box body and are arranged in sequence from bottom to top. The bottom soil flow collection trough, the middle soil flow collection trough and the surface runoff collection trough are all connected to the collecting barrel through a water pipe.

4. The device for measuring flooding process in soil on a slope based on a rock-soil interface depression according to claim 3, characterized in that: the second end is larger than the first end; and / or Each of the U-shaped lining plates is provided with overlapping edges at both ends thereof; and / or Along the direction from the first end to the second end, the continuous concave support frame is provided with a plurality of vertical support plates; and / or A detachable cover is provided on the upper portion of each rectangular depression; and / or The U-shaped liner includes an arc portion at the bottom and vertical portions on both sides of the arc portion. The radius of the arc portion is R, the slope of the continuous concave support frame soil is θ, θ is the radian, b is the box width, and the volume of the arc portion V is 圆弧 for: V 圆弧 =R²×b[π / 2-θ-(sin2θ) / 2]; According to the soil slope θ of the continuous concave support frame and the depth h of the U-shaped liner, the volume V of the diamond part of the U-shaped liner is obtained. 菱形 : V 菱形 =2R×h×b×cos²θ; According to the soil slope θ of the continuous concave support frame, the radius R of the arc part and the depth h of the U-shaped liner, the volume of the depression enclosed by the U-shaped liner and the interior of the box is obtained: V=2R×h×b×cos²θ+R²×b[π / 2-θ-(sin2θ) / 2]; and / or The bottom of the support box is provided with universal wheels, which facilitate the movement of the box; and / or The bottom mid-soil flow collection trough, the middle mid-soil flow collection trough and the surface runoff collection trough all include a triangular plate located on the downward-inclined side of the box body, one side of the triangular plate is fixed to the downward-inclined side of the box body, and the other two sides of the triangular plate are provided with baffles. The end of the triangular plate away from the downward-inclined side of the box body is connected to the water pipe, and a flow meter is connected to the collecting barrel.

5. An experimental method for measuring a flooding process in soil on a slope using a device for measuring a flooding process in a rock-soil interface depression according to any one of claims 1 to 4, characterized in that: The steps include: Providing transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3; Fill the box with transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3 from bottom to top; Adjust the cabinet to an inclined angle; Set the rainfall intensity, turn on the velocity measurement system and laser emission system after the rainfall begins, and collect flow samples through the collection component at the same time.

6. The experimental method of the device for measuring flooding process in soil on a slope based on a rock-soil interface depression according to claim 5, characterized in that: Mixing the first type of transparent soil and the fourth type of transparent soil at a mass ratio of 1:4, 1:2 and 1:1 respectively to obtain transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3; and / or The thickness of the transparent soil sample T1 is 10 cm, the thickness of the transparent soil sample T2 is 10 cm, and the thickness of the transparent soil sample T3 is 20 cm; and / or The rainfall intensity is set to seven gradient rainfalls of 5mm / h, 10mm / h, 30mm / h, 60mm / h, 90mm / h, 120mm / h and 150mm / h. The duration of each gradient rainfall is 45 minutes. The flow meters connected to the mid-flow collection trough at the bottom of the box, the mid-flow collection trough in the middle and the surface runoff collection trough automatically collect the flow rate every 1 minute. After each rainfall, the next rainfall will be carried out after a 30-minute pause or 3-5 days of suspension.

7. The experimental method of the device for measuring flooding process in soil on a slope based on a rock-soil interface depression according to claim 6, characterized in that: The first type of transparent soil acquisition method includes: The fused quartz sand was sieved into 0~1mm, 1~2mm, 2~3mm, 3~5mm, 5~8mm, 8~10mm, 10~20mm and 20~40mm; Mix 0-1 mm and 1-2 mm in a mass ratio of 1:1 to obtain 0-2 mm fused quartz sand; Add pore fluid into 0-2 mm fused quartz sand so that the pore fluid uniformly wets the surface of the 0-2 mm fused quartz sand to form sample a; Place sample a in a vacuum environment and exhaust for 6 hours to 10 hours to obtain sample b; In a vacuum environment, continue to add pore fluid to sample b while continuing to evacuate until the liquid level of the pore fluid submerges the upper surface of sample b, forming sample c; Remove sample c from the vacuum environment and allow it to stand at room temperature for 12 to 16 hours to form sample d, i.e., the first type of transparent soil; and / or The method for obtaining the second type of transparent soil comprises: mixing fused quartz sands of 2-3 mm, 3-5 mm, 5-8 mm, and 8-10 mm in a mass ratio of 1:1:1:1 to obtain fused quartz sands of 2-10 mm; the remaining steps are the same as those of the method for preparing the first type of transparent soil; and / or The method for obtaining the third type of transparent soil includes: mixing 10-20 mm and 20-40 mm fused quartz sand in a mass ratio of 1:1 to obtain 10-40 mm fused quartz sand; the remaining steps are the same as the method for preparing the first type of transparent soil.

8. The experimental method of the device for measuring flooding process in soil on a slope based on a rock-soil interface depression according to claim 7, characterized in that: The pore fluid includes n-dodecane and No. 15 white oil, with a mass ratio of n-dodecane to No. 15 white oil of 1:

4. After the mixture is prepared, Nile red dye is added until the pore fluid is completely colored; and / or The second type of transparent soil and the third type of transparent soil are mixed in a mass ratio of 1:1 to obtain the fourth type of transparent soil.

9. The experimental method of the device for measuring flooding process in soil on a slope based on a rock-soil interface depression according to claim 5, characterized in that: The top, middle and bottom of the slope of transparent sample soil T1, transparent sample soil T2 and transparent sample soil T3 backfilled in the box, and multiple soil moisture monitoring probes and matrix suction probes are set at the edge and center of the U-shaped liner.

10. The experimental method of the device for measuring flooding process in soil on a slope based on a rock-soil interface depression according to claim 6, characterized in that: Before rainfall begins, the laser emission system and the velocity measurement system are turned on. The planar laser emitted by the laser and the light-guide arm slices the transparent soil sample T1 and / or transparent soil sample T2 and / or transparent soil sample T3 in the box to form laser speckles, ensuring that the laser beam can evenly illuminate the cross-section of the seepage field of the transparent soil sample T1 and / or transparent soil sample T2 and / or transparent soil sample T3 in the depression structure area and the non-depression structure area; the high-speed camera is used to record the laser speckles, and the image analyzer is used to analyze the laser speckles. The high-speed camera and the image analyzer cooperate with each other to capture the detailed flow velocity distribution density, size and direction of the soil flow around the U-shaped liner at the bottom of the box during the entire rainfall process.

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