Research on the test device and method of the influence of extreme rainfall on water diversion channel

Abstract

The application relates to a test device and a test method for studying the influence of extreme rainfall on a water diversion channel, which comprises a channel filling box, a channel model filled in the channel filling box, the channel model comprising two side channel slopes and a channel lining plate between the two side channel slopes, and a drainage body filled on one side of the channel model close to a first drainage hole; a rainfall simulation assembly simulating a channel rainfall scene; a channel water supply assembly simulating a channel water supply scene; a groundwater water supply assembly located on one side of the simulation box, the groundwater water supply assembly comprising a groundwater storage tank, water in the groundwater storage tank seeping into the channel model through a water permeable hole to simulate groundwater; and a sensor assembly buried in the channel model to collect channel bottom, channel slope pore water pressure and channel slope displacement. The application considers the influence of water, groundwater level and rainfall in the channel on the channel, and has important significance for further clarifying the channel slope disaster mechanism and disaster prevention under the extreme rainfall working condition.

Description

Technical Field

[0001] This invention relates to the field of water diversion engineering protection technology, and in particular to an experimental device and method for studying the impact of extreme rainfall on water diversion channels. Background Technology

[0002] In recent years, global climate change has been abnormal, with frequent extreme weather events. Extreme rainfall poses a threat to the operational safety of long-distance water diversion projects. Under extreme rainfall conditions, the slopes of deeply excavated and high-filled canals are at risk of landslides due to rainwater infiltration and erosion. Simultaneously, rainfall raises the regional groundwater level, further increasing the stability risk of deeply excavated canal sections and causing the canal lining to heave, affecting water supply security. Furthermore, because the top of the slopes in deeply excavated canals is level with the surrounding ground, rainwater from the surrounding area accumulates and rises, exceeding the top elevation of the flood control dike in the excavated section, posing a risk of external water entering the canal. This not only pollutes the canal water but also affects slope stability. It is evident that extreme rainfall has a significant impact on the slopes of water diversion projects, especially deeply excavated canals.

[0003] Current research methods for canal slopes are mostly similar to those for slope stability studies, neglecting the influence of water within the canal and failing to simultaneously reflect the various impacts of extreme rainfall at different times. Therefore, researching an experimental device to explore the disaster-causing characteristics of extreme rainfall on water diversion canals is of great significance for further elucidating the disaster mechanism of canal slopes under extreme rainfall conditions and for disaster prevention and control. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the technical defects in the prior art where the study of channel slope ignores the influence of water in the channel and is difficult to reflect the various effects of extreme rainfall at different time periods.

[0005] To address the aforementioned technical problems, this invention provides an experimental apparatus for studying the impact of extreme rainfall on water diversion channels, comprising:

[0006] A channel filling box, wherein a first water inlet hole and a first drainage hole are respectively opened on both sides of the channel filling box, and a channel model is filled in the channel filling box, wherein the channel model includes two channel slopes and a channel lining plate located between the two channel slopes;

[0007] A rainfall simulation component that simulates a channel rainfall scenario, the rainfall simulation component including multiple nozzles capable of spraying water, the nozzles being located on the upper side of the channel model;

[0008] A channel water supply component that simulates a channel water supply scenario, wherein the channel water supply component is connected to the first water inlet hole to supply water to the channel model, and the water in the channel model is discharged from the first drain hole;

[0009] A groundwater supply component is located on one side of a channel filling box. The groundwater supply component includes a groundwater storage tank, which shares a side plate with the channel filling box. The side plate is a partition with multiple permeable holes. Water in the groundwater storage tank seeps into the channel model through the permeable holes to simulate groundwater. A second drainage hole is provided on the side of the channel filling box away from the permeable holes. A drainage body is filled on the side of the channel model near the second drainage hole. Water in the groundwater storage tank seeps into the channel model through the permeable holes and is discharged from the second drainage hole through the drainage body to simulate flowing groundwater. The direction of groundwater flow in the channel model is perpendicular to the direction of water flow in the channel supply.

[0010] A sensor assembly is embedded within the channel model to collect pore water pressure and slope displacement at the channel bottom and slope.

[0011] Preferably, the method for filling the channel model includes:

[0012] A drainage body is filled into the channel filling box on the side near the second drainage hole;

[0013] Use clay to fill the channel filling box to the preset height to obtain a filled channel filling box;

[0014] A channel is excavated in the filled channel filling box to obtain a channel model.

[0015] Preferably, the plurality of water-permeable holes are distributed in a matrix array.

[0016] Preferably, a water baffle is attached to one side of the partition, and the water baffle can move up and down and block part of the water-permeable holes to simulate groundwater levels at different elevations.

[0017] Preferably, a flood control dike is provided at the ground level of the channel model, and the partition is provided with multiple layers of permeable holes from bottom to top. The height of the center point of the top layer of permeable holes on the partition is higher than or equal to the top elevation of the flood control dike.

[0018] When the baffle moves vertically so that only the top permeable hole is exposed, the water in the groundwater storage tank flows through the top permeable hole, crosses the flood control dike, and enters the channel model to simulate the working condition of external water entering the channel.

[0019] Preferably, the rainfall simulation component includes a first pump body and a rainfall pipeline, with multiple nozzles disposed on the rainfall pipeline. The first pump body is capable of pumping water at different flow rates into the rainfall pipeline to simulate rainfall of different intensities.

[0020] Preferably, the channel model has multiple first drainage pipes installed inside the channel slope. The multiple first drainage pipes are respectively installed on different sections of the channel model, and the surface of the first drainage pipes is provided with multiple holes to facilitate the infiltration of water into the channel slope.

[0021] When the first drainage pipe is buried inside the channel model, geotextile is used to wrap the first drainage pipe to prevent soil particles from entering and clogging it.

[0022] Preferably, the channel model is provided with multiple monitoring sections in the horizontal and vertical directions, and pore water pressure gauges are buried at the same elevation at the bottom of the channel lining plate and the bottom of the channel slope, and inclinometers are buried on the channel slope.

[0023] This invention discloses an experimental method for studying the impact of extreme rainfall on water diversion channels, based on the above-mentioned experimental apparatus simulating one or more of the following operating conditions:

[0024] Condition 1: Use the rainfall simulation component to simulate rainfall conditions of different intensities, specifically including: by adjusting the water flow rate and spraying time of the sprinklers, record the scouring of the channel model's slope at regular intervals.

[0025] Working Condition 2: Using groundwater supply components to simulate the impact of groundwater rise on channel slope seepage and stability, specifically including: allowing water in the groundwater storage tank to flow into the channel model of the channel filling box at different water levels through some permeable holes on the shielding partition;

[0026] Working condition 3: Using groundwater supply components to simulate external water entering the canal, specifically including: making the permeable holes on the top layer of the partition higher than the highest point of the canal model, blocking part of the permeable holes on the partition to ensure that the permeable holes on the top layer are unobstructed, and the water level of the groundwater supply tank is higher than the permeable holes on the top layer so that the water flows through the permeable holes on the top layer, crosses the flood control dike, and flows along the canal slope towards the canal.

[0027] In all the above operating conditions, the data of the sensor components are recorded at preset time intervals.

[0028] This invention discloses an experimental method for studying the impact of extreme rainfall on water diversion channels, and an experimental apparatus for studying the impact of extreme rainfall on water diversion channels, comprising any of the following combinations of operating conditions:

[0029] Combination working condition one, simulating the working conditions during the completion period of the water diversion channel, specifically includes: the channel water supply component is not turned on, the groundwater supply component provides low-level groundwater to the channel model, and the rainfall simulation component is not turned on;

[0030] Combination Condition 2: Simulates the normal operation of the water diversion channel, specifically including: supplying water to the channel through the channel water supply component, providing low-level groundwater to the channel model through the groundwater supply component, and the rainfall simulation component is not activated;

[0031] Combined working condition three: Simulate the working condition of the water diversion channel in the early stage of rainfall, specifically including: supplying water into the channel through the channel water supply component, providing low-level groundwater to the channel model through the groundwater supply component, and simulating low-intensity rainfall through the rainfall simulation component;

[0032] Combination working condition four: Simulate the working condition of the water diversion channel during a period of continuous rainfall, specifically including: supplying water into the channel through the channel water supply component, providing high-level groundwater to the channel model through the groundwater supply component, and simulating high-intensity rainfall through the rainfall simulation component;

[0033] Combination Condition 5: Simulates the operation of the water diversion channel after rainfall ends. Specifically, this includes: supplying water to the channel through the channel water supply component, providing high-level groundwater to the channel model through the groundwater supply component, and turning off the rainfall simulation component after a period of time.

[0034] The technical solution of the present invention has the following advantages compared with the prior art:

[0035] 1. This invention can simulate rainfall of different intensities by setting up a rainfall simulation component, simulate groundwater by setting up a groundwater supply component, and simulate channel water supply by setting up a channel water supply component.

[0036] 2. Under extreme rainfall conditions, canal slopes are eroded by rainwater, and rainwater infiltration increases the weight of the topsoil. Simultaneously, prolonged regional rainfall raises the groundwater level, affecting canal slope stability. Furthermore, when rainfall intensity is excessive and surrounding rainwater converges too quickly, there is a risk of external water entering the canal. Therefore, the impact of extreme rainfall on excavated canals manifests in multiple ways, influenced by the combined effects of rainfall intensity and duration. This invention creatively analyzes the operational safety of canals under extreme rainfall conditions by designing an experimental device that integrates multiple influencing factors such as rainfall, groundwater, and water flow within the canal. By adjusting rainfall intensity, groundwater level, and canal design water level, and combining various scenarios, the operational behavior of the canal slope is analyzed based on sensor data, resulting in simulations that more closely reflect actual engineering conditions.

[0037] 3. This invention is used for indoor model tests of channel operation under extreme rainfall. By simulating different rainfall intensities, different groundwater levels at different elevations, and different channel water levels, it can intuitively present various forms of disaster and failure scenarios of channel slopes.

[0038] 4. This invention can obtain the spatiotemporal evolution of rainfall intensity transformation process and pore water pressure and canal slope deformation before and after the application of emergency measures online, which provides convenient conditions for accurate analysis of canal slope failure under extreme rainfall conditions and provides a theoretical basis for the maintenance of canal slopes under extreme rainfall conditions, thereby reducing the possibility of canal slope failure.

[0039] 5. This invention has the advantages of simple principle, convenient operation, fast monitoring, reusability, and high test error tolerance. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the experimental apparatus used in this invention to study the impact of extreme rainfall on water diversion channels;

[0041] Figure 2 for Figure 1 A sectional view along direction A;

[0042] Figure 3 for Figure 1 A sectional view along direction B, where direction B is perpendicular to direction A;

[0043] Figure 4 This is a schematic diagram of the first drainage pipe;

[0044] Figure 5 This is a diagram showing the splicing of the channel lining panels.

[0045] Explanation of reference numerals in the accompanying drawings: I. Channel water source storage tank; II. Channel filling tank; III. Channel tailrace tank; IV. Groundwater storage tank; V. Main storage tank; 1. First inlet hole; 2. First drain hole; 3. Tailrace drain hole; 4. Second drain hole; 5. Water source supply switch; 6. Groundwater supply switch; 7. Rainfall switch; 8. Rainfall pipeline; 9. Water pump; 10. Channel model; 11. Channel lining plate; 12. First drain pipe; 13. Drainage body; 14. Water baffle; 15. Inclinometer; 16. Pore water pressure gauge; 17. Hole; 18. Flood control dike. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0047] Reference Figures 1-5 As shown, the present invention discloses an experimental device for studying the impact of extreme rainfall on water diversion channels, including a channel filling box II, a rainfall simulation component, a channel water supply component, a groundwater supply component, and a sensor component.

[0048] A first water inlet 1 and a first drainage outlet 2 are respectively opened on both sides of the channel filling box II. A channel model 10 is filled in the channel filling box II. The channel model 10 includes two channel slopes and a channel lining plate 11 located between the two channel slopes.

[0049] The rainfall simulation component simulates a channel rainfall scenario. It includes multiple sprinklers capable of spraying water, located on the upper side of the channel model 10. Rainfall can be simulated by spraying water from these sprinklers. The sprinklers can be atomizing nozzles.

[0050] The channel water supply component simulates a channel water supply scenario. The channel water supply component is connected to the first inlet hole 1 to supply water to the channel model 10. Since the first inlet hole 1 and the first drain hole 2 are located on both sides of the channel filling box II, the channel water supply component supplies water to the channel model 10 through the first inlet hole 1, and the water in the channel model 10 is discharged through the first drain hole 2. In this way, the water flow in the channel can be simulated.

[0051] The groundwater supply assembly is located on one side of the channel filling box II. The assembly includes a groundwater storage tank IV, which shares a side plate with the channel filling box II. This side plate is a partition with multiple permeable holes. Water from the groundwater storage tank IV seeps into the channel model 10 through these holes to simulate groundwater. A second drainage hole 4 is located on the side of the channel filling box II away from the permeable holes, while a drainage body 13 is constructed on the side of the channel model 10 closest to the second drainage hole 4. Thus, water from the groundwater storage tank IV seeps into the channel model 10 through the permeable holes and is discharged through the drainage body 13 from the second drainage hole 4, thereby simulating flowing groundwater. The flow direction of the groundwater in the channel model 10 is perpendicular to the flow direction of the channel water supply.

[0052] Sensor components are embedded within the channel model 10 to collect pore water pressure and slope displacement at the channel bottom and slope. The working principle of this invention is as follows: by setting up a rainfall simulation component, rainfall of different intensities can be simulated; by setting up a groundwater supply component, groundwater can be simulated; and by setting up a channel water supply component, channel water supply can be simulated. Under extreme rainfall conditions, the channel slope will be eroded by rainwater, and rainwater infiltration increases the weight of the surface soil. Simultaneously, prolonged regional rainfall will raise the groundwater level, affecting the stability of the channel slope. Furthermore, when the rainfall intensity is too high and the surrounding rainwater converges too quickly, there is a risk of external water entering the channel. Therefore, the impact of extreme rainfall on excavated channels manifests in multiple aspects, influenced by the combined effects of rainfall intensity and duration. This invention creatively analyzes the operational safety state of channels under extreme rainfall conditions by designing an experimental device that integrates multiple influencing factors such as rainfall, groundwater, and water flow within the channel. By adjusting rainfall intensity, groundwater level, and channel design water level, and combining various scenarios, the operational behavior of the channel slope is analyzed based on sensor data, and the simulated results more closely reflect actual engineering conditions.

[0053] Specifically, firstly, this invention is used for indoor model tests of channel operation under extreme rainfall. By simulating different rainfall intensities, different groundwater levels at different elevations, and different channel water levels, it can intuitively present various forms of disaster and failure scenarios of channel slopes.

[0054] Secondly, this invention can obtain the spatiotemporal evolution of rainfall intensity transformation process and pore water pressure and canal slope deformation before and after the application of emergency measures online, which provides convenient conditions for accurate analysis of canal slope failure under extreme rainfall conditions and provides a theoretical basis for the maintenance of canal slopes under extreme rainfall conditions, thereby reducing the possibility of canal slope failure.

[0055] Thirdly, this invention has the advantages of simple principle, convenient operation, fast monitoring, reusability, and high test error tolerance.

[0056] Furthermore, in this invention, the filling method of the channel model 10 includes: first, filling a drainage body 13 on the side of the channel filling box II near the second drainage hole 4; then, using clay to fill the channel filling box II to a preset height to obtain a filled channel filling box II. Here, filling to the preset height can simulate the ground; finally, digging a channel in the filled channel filling box II to obtain the channel model 10. The drainage body 13 can be a sand and gravel drainage body 13, which facilitates the drainage of water in the channel, thereby making it easy for water to form in the channel. The drainage body 13 at the bottom of the channel model 10 is used to collect and drain the high groundwater on the other side of the channel. The filling height of the drainage body 13 is higher than the drainage pipe of the model filling box, and geotextile is laid at the contact parts between the drainage body 13 and the model box.

[0057] In this invention, multiple permeable holes are arranged in a matrix array. A baffle plate 14 is attached to one side of the partition, and the baffle plate 14 can move up and down to block some of the permeable holes to simulate groundwater levels at different elevations. For example, when it is necessary to raise the groundwater level, the baffle plate 14 is moved upward so that more permeable holes are not blocked.

[0058] In another embodiment, a flood control dike 18 is provided at the ground level of the channel model 10. The dike has multiple layers of permeable holes from bottom to top, with the center point of the top layer of permeable holes on the dike being higher than or equal to the top elevation of the flood control dike 18. When the baffle plate 14 moves vertically so that only the top layer of permeable holes is exposed at the top of the dike, water from the groundwater storage tank IV flows sequentially through the top layer of permeable holes and the flood control dike 18 into the channel model 10 to simulate the inflow of external water into the channel. Specifically, the baffle plate 14 can block the permeable holes in the lower area, exposing only the top layer of permeable holes (here, multiple permeable holes are arranged layer by layer from bottom to top), thus simulating the inflow of external water into the channel.

[0059] The rainfall simulation component includes a first pump body and rainfall pipes 8. Multiple nozzles are installed on the rainfall pipes 8. The first pump body can pump water at different flow rates into the rainfall pipes 8 to simulate rainfall of different intensities. Multiple rainfall pipes 8 can be installed, with equal spacing between them at the same height. Each rainfall pipe 8 can also have multiple nozzles installed at equal intervals to simulate relatively uniform regional rainfall.

[0060] Multiple first drainage pipes 12 are installed inside the channel slope of the channel model 10. The multiple first drainage pipes 12 are respectively arranged at different cross-sections of the channel model 10. Multiple holes 17 are provided on the surface of the first drainage pipes 12 to facilitate water infiltration into the channel slope. When the first drainage pipes 12 are buried inside the channel model 10, geotextile is wrapped around the first drainage pipes 12 to prevent soil particles from entering and clogging the first drainage pipes 12.

[0061] In this invention, multiple monitoring sections are set in the transverse and longitudinal directions of the channel model 10. Specifically, pore water pressure gauges 16 are buried at the same elevation at the bottom of the channel lining plate 11 and the bottom of the channel slope, and inclinometers 15 are buried on the channel slope.

[0062] This invention discloses an experimental method for studying the impact of extreme rainfall on water diversion channels, based on the above-mentioned experimental apparatus simulating one or more of the following operating conditions:

[0063] Condition 1: Use the rainfall simulation component to simulate rainfall conditions of different intensities, specifically including: by adjusting the water flow rate and water spraying time of the nozzles, record the scouring of the slope of the channel model 10 at regular intervals.

[0064] Working condition 2: Using groundwater supply components to simulate the impact of groundwater rise on channel slope seepage and stability, specifically including: allowing water in the groundwater storage tank to flow into the channel model 10 of the channel filling box II at different water levels through some permeable holes on the shielding partition;

[0065] Condition 3: Use groundwater supply components to simulate external water entering the canal. Specifically, this includes: making the top permeable holes on the partition plate higher than the top elevation of the flood control dike 18 of the canal model 10, and blocking the lower part of the permeable holes on the partition plate to ensure that the top permeable holes are unobstructed, so that the water level of the groundwater supply tank is higher than the top permeable holes to supply water to the canal model 10.

[0066] In all the above operating conditions, the data of the sensor components are recorded at preset time intervals.

[0067] This invention can also simulate the following combinations of operating conditions:

[0068] Combination working condition one, simulating the working condition during the completion period of the water diversion channel, specifically includes: the channel water supply component is not turned on, low-level groundwater is provided to channel model 10 through the groundwater supply component, and the rainfall simulation component is not turned on;

[0069] Combination working condition 2: Simulates the working conditions during the normal operation of the water diversion channel, specifically including: supplying water to the channel through the channel water supply component, providing low-level groundwater to channel model 10 through the groundwater supply component, and the rainfall simulation component is not activated;

[0070] Combined working condition three: Simulate the working condition of the water diversion channel in the early stage of rainfall, specifically including: supplying water into the channel through the channel water supply component, providing low-level groundwater to the channel model 10 through the groundwater supply component, and simulating low-intensity rainfall through the rainfall simulation component;

[0071] Combination working condition four: Simulating the working condition of water channels during a period of continuous rainfall, specifically including: supplying water into the channel through the channel water supply component, providing high-level groundwater to channel model 10 through the groundwater supply component, and simulating high-intensity rainfall through the rainfall simulation component;

[0072] Combination Condition 5: Simulates the operation of the water diversion channel after rainfall ends, specifically including: supplying water to the channel through the channel water supply component, providing high-level groundwater to channel model 10 through the groundwater supply component, and turning off the rainfall simulation component after a period of time.

[0073] The technical solution of the present invention will be further described and explained below with reference to specific embodiments.

[0074] Example 1

[0075] The experimental setup used in this example to study the disaster-causing characteristics of extreme rainfall on water diversion channels is as follows: Figures 1-5As shown, the model box consists of a channel water source storage tank I, a channel filling tank II, a channel tailwater tank III, and a groundwater storage tank IV. The top of the model box is open, and the rest is made of transparent tempered glass. A water inlet valve is installed at the first inlet hole 1 on the partition between the channel water source storage tank I and the channel filling tank II. A drainage valve is installed at the first drain hole 2 on the partition between the channel filling tank II and the channel tailwater tank III. The partition between the channel filling tank II and the groundwater storage tank IV has 65 holes in 5 layers, and a water baffle 14 is installed in the middle of the partition, which can be lifted from the top of the partition. Both the channel filling tank II and the channel tailwater tank III have drainage holes on one side. Specifically, the channel filling tank II has a first drainage hole 2 to drain water from the channel, and the channel tailwater tank III has a tailwater drainage hole 3. In this example, the dimensions of channel water source storage tank I are 1.5m×4m×2m (length×width×height), the dimensions of channel filling tank II are 6m×4m×2m (length×width×height), the dimensions of channel tailwater tank III are 1.5m×4m×2m (length×width×height), the dimensions of groundwater storage tank IV are 6m×2m×2m (length×width×height), and the diameter of tailwater drainage hole 3 and the second drainage hole 4 are both 3cm.

[0076] The rainfall simulation system in this example consists of a main water storage tank V, a water pump 9, a rainfall switch 7, and a rainfall pipeline 8. The rainfall pipeline 8 is equipped with atomizing nozzles, allowing for adjustment of the water output. The channel water supply system consists of a main water storage tank V, a channel water source storage tank I, a water pump 9, a water source supply switch 5, and an inlet level valve 1. The groundwater supply system consists of a water storage tank V, a channel water source storage tank IV, a water pump 9, a groundwater supply switch 6, and a water baffle 14.

[0077] In this embodiment, the water supply pipeline consists of a main pipe and three branch pipes. One end of the main pipe is connected to the main water storage tank and is equipped with a water pump. The three branch pipes are respectively connected to the channel water source storage tank IV, the groundwater storage tank IV, and the rainwater pipeline. Each branch pipe is equipped with an on / off switch.

[0078] In this embodiment, the inlet level valve and the outlet level valve are located on the partition between the channel water source storage tank IV and the model filling tank II, and on the partition between the model filling tank II and the channel tailwater tank III, respectively. The inlet level valve corresponds to the first inlet hole 1, and the outlet level valve corresponds to the first outlet hole 2.

[0079] In this example, the positions of the inlet level valve 1 and the outlet level valve 2 are both fixed at 40cm from the bottom of the tank. The level valves are equipped with floats, which are connected to the valves by nylon ropes. For the inlet level valve 1, the valve is closed when the nylon rope is taut. For the outlet level valve 2, the valve is open when the nylon rope is taut.

[0080] In this embodiment, the clay is preferably made from clay excavated on-site from the channel slope to be simulated. The particle size distribution and initial moisture content of the clay are the same as those of the undisturbed soil. When preparing the clay layer, the clay excavated from the channel site is dried outdoors, and soil samples are prepared according to the undisturbed soil particle size distribution and initial moisture content. Additionally, local materials are selected to prepare the drainage body 13 on one side of the channel bottom. When filling the channel model 10, the clay is compacted layer by layer to the same height, and then the channel and channel slope morphology are excavated to simulate the excavation environment. In this example, the channel model 10 has symmetrically distributed channel slopes on both sides, a channel bottom width of 0.8m, a first-level channel slope AB with a slope ratio of 1:1, a first-level walkway BC with a width of 0.2m, a second-level channel slope CD with a slope ratio of 1.05:1, a second-level walkway DE with a width of 0.15m, a third-level channel slope EF with a slope ratio of 1:1, and a third-level walkway FG that is the original ground surface. A flood control dike 18 is set up on the side of the high groundwater level of the channel model 10, with the top elevation of the dike level with the position of the top hole of the partition.

[0081] In this example, the channel model is equipped with 5 sets of pore water pressure gauges 16, 3 sets of inclinometers 15, and 5 sets of first drainage pipes 12, all arranged perpendicular to the water flow direction. The instruments and drainage pipes were drilled and buried after the model was constructed. Each set of pore water pressure gauges 16 contains 5 instruments, symmetrically distributed on both banks, located in the middle of the channel bottom, at the bottom of the first-level channel slope AB, and at the bottom of the second-level walkway DE, all at the same elevation. Each set of inclinometers contains 2 instruments, respectively located on the second-level walkway DE and the third-level walkway FG on the side of the channel slope with higher groundwater levels, with the bottom elevations of the inclinometers being the same. Each set of first drainage pipes contains 3 pipes, buried on the channel slope with higher groundwater levels; one pipe is installed on the first-level channel slope AB, and two on the second-level channel slope CD. The first drainage pipes 12 have a total of 20 holes 17, which are wrapped with geotextile during installation to prevent soil particles from clogging them.

[0082] In this example, the channel model is constructed with precast thin-layer concrete lining slabs 11. Each slab measures 0.4m x 0.4m and is 0.5cm thick. The lining slabs 11 are laid using a splicing method, with each slab equipped with clips. The clips on the precast thin-layer concrete lining slabs 11 can be cut flat at the laying edges. Rubber waterstops (not shown in the figure) are installed at the joints of the precast thin-layer concrete lining slabs 11, and a layer of geomembrane is pre-laid at the bottom to further prevent water from seeping into the channel bottom.

[0083] Example 2

[0084] This embodiment is the test method of the test device for studying the disaster-causing characteristics of extreme rainfall on water diversion channels in Embodiment 1, including the following steps:

[0085] 1) Set the float height of the inlet level valve 1 and the outlet level valve 2, fill the main water tank V with water, turn on the water supply switch 5, and turn off the water supply switch 5 after the water level in the channel model channel stabilizes.

[0086] 2) Simulate different working conditions according to research needs.

[0087] Simulation of Condition 1: Turn on the rainfall switch 7 separately, set the rainfall intensity of the rainfall pipe 8, and simulate the required rainfall conditions;

[0088] Working condition 2 simulation: The groundwater supply switch 6 is turned on separately to fill the groundwater storage tank IV with water, and the height of the baffle plate 14 is adjusted to set different groundwater elevations to simulate the working condition of groundwater level rise caused by regional rainfall.

[0089] Working condition 3 simulation: Open the groundwater supply switch 6 separately to fill the groundwater storage tank IV with water, close the baffle 14, so that the water level in the groundwater storage tank IV is higher than the top permeable hole of the partition, to simulate the working condition of external water entering the canal.

[0090] 3) Under various working conditions, record the readings of each pore water pressure sensor 16 and inclinometer 15 every 20 minutes for 7 days, and the test will end.

[0091] When simulating high groundwater conditions, the drainage holes 12 inside the canal slope can be artificially blocked to compare the impact of drainage measures on the stability of the canal slope when the groundwater level is high.

[0092] When simulating the situation of external water entering the canal, colored tarpaulins can be selectively laid on the top of the canal slope GF to study the effectiveness of emergency measures for external water entering the canal.

[0093] Various operating conditions can be simulated simultaneously to form combined operating conditions:

[0094] ①Completion period: No water in the canal + low groundwater level on the canal slope + no rainfall (water supply switch 5 is closed, rainfall switch 7 is closed, groundwater supply switch 6 is open, water baffle 14 is slightly raised - water passes through the bottom 5 holes of the baffle).

[0095] ② Normal operation period: There is water in the channel + the groundwater level is low on the channel slope + there is no rainfall (the water supply switch 5 is open, the rainfall switch 7 is closed, the groundwater supply switch 6 is open, and the water baffle 14 is slightly raised - water passes through the bottom 5 holes of the baffle).

[0096] ③ Initial stage of rainfall: Water in the channel + low groundwater level on the channel slope + low-intensity rainfall (water supply switch 5 is opened, rainfall switch 7 is opened, groundwater supply switch 6 is opened, and water baffle 14 is slightly raised) - water passes through the bottom 5 holes of the partition.

[0097] ④ During the continuous rainfall period: there is water in the channel + the groundwater level is high on the channel slope + high-intensity rainfall (water supply switch 5 is opened, rainfall switch 7 is opened, groundwater supply switch 6 is opened, and water baffle 14 is raised significantly - water passes through the bottom 3 layers of 39 holes of the baffle).

[0098] ⑤ Rainfall ends: There is water in the channel + the groundwater level is high on the channel slope + the rainfall stops after a period of time (the water supply switch 5 is opened, the rainfall switch 7 is turned on for a period of time and then closed, the groundwater supply switch 6 is opened, and the water baffle 14 is raised significantly - water passes through the 39 holes in the 3 layers at the bottom of the baffle).

[0099] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An experimental apparatus for investigating the effects of extreme rainfall on a water diversion channel, characterized in that, The application relates to a channel filling box, a rainfall simulation assembly, a channel water supply assembly, a groundwater water supply assembly and a sensor assembly. The channel filling box is provided with a first water inlet and a first water outlet on two sides, and a channel model is filled in the channel filling box, wherein the channel model comprises two side channel slopes and a channel lining plate between the two side channel slopes. The rainfall simulation assembly simulates a channel rainfall scene, and comprises a plurality of water-spraying nozzles arranged on the upper side of the channel model. The channel water supply assembly simulates a channel water supply scene, and is connected with the first water inlet to supply water to the channel model. The groundwater water supply assembly is arranged on one side of the channel filling box, and comprises a groundwater storage tank which shares a side plate with the channel filling box. The side plate is a partition plate, and a plurality of water-permeable holes are arranged on the partition plate.

2. A test apparatus for investigating the effects of extreme rainfall on a water diversion channel according to claim 1, characterised in that, The water in the groundwater storage tank seeps into the channel model through the water-permeable holes to simulate groundwater. The side of the channel filling box away from the water-permeable holes is provided with a second water outlet. The side of the channel model close to the second water outlet is filled with a drainage body. The water in the groundwater storage tank seeps into the channel model through the water-permeable holes and is discharged from the second water outlet through the drainage body to simulate flowing groundwater.

3. The test apparatus for studying the effects of extreme rainfall on a water diversion channel according to claim 1, wherein The water flow direction of the groundwater in the channel model is perpendicular to the water flow direction of the channel water supply.

4. The test apparatus for studying the effects of extreme rainfall on a water diversion channel according to claim 1, wherein The sensor assembly is embedded in the channel model to collect channel bottom, channel slope pore water pressure and channel slope displacement.

5. A test apparatus for investigating the effects of extreme rainfall on a water diversion channel according to claim 4, characterised in that, The filling method of the channel model comprises the following steps. A drainage body is filled on the side of the channel filling box close to the second water outlet.

6. The test apparatus for studying the effects of extreme rainfall on a water diversion channel according to claim 1, wherein The channel filling box is filled with clay to a preset height to obtain a filled channel filling box.

7. The test apparatus for studying the effects of extreme rainfall on a water diversion channel according to claim 1, wherein A channel is dug in the filled channel filling box to obtain a channel model. The water-permeable holes are arranged in a matrix array. A water baffle is arranged on one side of the partition plate and can move up and down to block part of the water-permeable holes to simulate different groundwater levels. A flood control dike is arranged on the ground of the channel model. The center point of the top layer of water-permeable holes on the partition plate is higher than or equal to the top elevation of the flood control dike. When the water baffle moves along the vertical direction to make the top layer of water-permeable holes exposed on the top of the partition plate, the water in the groundwater storage tank flows through the top layer of water-permeable holes, overflows the flood control dike and enters the channel model along the channel slope to simulate the working condition of external water entering the channel. The rainfall simulation assembly comprises a first pump body and a rainfall pipeline. The first pump body can pump water into the rainfall pipeline at different flow rates to simulate rainfall of different intensities. A plurality of first drainage pipes are arranged in the channel slope of the channel model. The surface of the first drainage pipe is provided with a plurality of holes to facilitate the seepage of water in the channel slope. The first drainage pipe is wrapped with geotextile to prevent soil particles from entering and blocking the first drainage pipe.

8. The test apparatus for studying the effects of extreme rainfall on a water diversion channel according to claim 1, wherein, The channel model is provided with a plurality of monitoring sections in the transverse and longitudinal directions, a pore water pressure gauge is arranged at the same elevation as the bottom of the channel lining plate and the bottom of the channel slope, and an inclinometer is arranged on the channel slope.

9. A test method for investigating the effect of extreme rainfall on a water diversion channel, characterised in that, The test device according to any one of claims 1-8 simulates one or more of the following working conditions: Working condition one: simulate different intensity rainfall conditions using the rainfall simulation assembly, specifically including: by adjusting the water flow and water spraying time of the spray head, the erosion of the slope surface of the channel model is recorded every certain period of time; Working condition two: simulate the influence of groundwater rising on seepage and stability of the channel slope using the groundwater supply assembly, specifically including: by shielding part of the water permeable holes on the baffle, water in the groundwater storage tank is allowed to flow into the channel filling tank at different water levels; Working condition three: simulate external water inflow into the channel using the groundwater supply assembly, specifically including: the water permeable holes on the top layer of the baffle are higher than the highest point of the flood control dike of the channel model, part of the water permeable holes on the baffle are shielded to ensure that the water permeable holes on the top layer are unobstructed, and the water level of the groundwater supply tank is higher than the water permeable holes on the top layer so that water flows through the water permeable holes on the top layer, overflows the flood control dike, and flows along the channel slope to the channel; Wherein, the data of the sensor assembly is recorded every certain period of time in the above working conditions.

10. A test method for studying the effect of extreme rainfall on a water diversion channel, based on the test device for studying the effect of extreme rainfall on a water diversion channel according to any one of claims 1-8, characterized in that, Any one of the following combined working conditions is included: Combined working condition one: simulate the working condition of the diversion and regulation channel during the completion period, specifically including: the channel water supply assembly is not turned on, the groundwater supply assembly is used to provide low water level groundwater to the channel model, and the rainfall simulation assembly is not turned on; Combined working condition two: simulate the working condition of the diversion and regulation channel during the normal operation period, specifically including: water is supplied to the channel through the channel water supply assembly, low water level groundwater is provided to the channel model through the groundwater supply assembly, and the rainfall simulation assembly is not turned on; Combined working condition three: simulate the working condition of the diversion and regulation channel during the initial period of rainfall, specifically including: water is supplied to the channel through the channel water supply assembly, low water level groundwater is provided to the channel model through the groundwater supply assembly, and the rainfall simulation assembly simulates low intensity rainfall; Combined working condition four: simulate the working condition of the diversion and regulation channel during the continuous rainfall period, specifically including: water is supplied to the channel through the channel water supply assembly, high water level groundwater is provided to the channel model through the groundwater supply assembly, and the rainfall simulation assembly simulates high intensity rainfall; Combined working condition five: simulate the working condition of the diversion and regulation channel after the rainfall ends, specifically including: water is supplied to the channel through the channel water supply assembly, high water level groundwater is provided to the channel model through the groundwater supply assembly, and the rainfall simulation assembly is turned on for a period of time and then turned off.

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