Method and system for evaluating protection effect of ecological revetment under dynamic water level impact

Abstract

The application provides a kind of ecological slope protection effect evaluation method and system under dynamic water level impact, related to ecological protection slope field, comprising: according to water level monitoring data, determine the pore water pressure time history data of each sampling node;Determine the seepage lag correction coefficient according to the water level change direction based on the pore water pressure time history data;Correct the pore water pressure time history data of each sampling node;According to the corrected pore water pressure time history data, generate corrected pore water pressure field, calculate the safety factor time history curve of sampling node under dynamic water level impact based on the plant root system parameters of target ecological slope protection and corrected pore water pressure field;According to the safety factor time history curve of each sampling node, determine the stability of target ecological slope protection.The problem of inaccurate safety factor caused by ignoring seepage lag direction and missing root hydrological effect of ecological slope protection under dynamic water level impact is solved, and the authenticity and reliability of target ecological slope stability evaluation are improved.

Description

Technical Field

[0001] This invention relates to the field of ecological slope protection, and in particular to a method and system for evaluating the protective effect of ecological slope protection under dynamic water level impact. Background Technology

[0002] Ecological slope protection is a method of slope protection that involves planting vegetation on the slope and utilizing the anchoring effect of the plant roots with the rock and soil to protect and reinforce the surface layer of the slope. This method both meets the requirements for slope surface stability and restores the damaged natural ecological environment. Common forms of ecological slope protection include plant-based slope protection, geosynthetic composite planting base slope protection, ecological gabion slope protection, vegetation-based ecological concrete slope protection, ecological bag slope protection, porous structure slope protection, and self-embedded retaining wall slope protection.

[0003] Stability refers to assessing whether a slope possesses sufficient anti-sliding capacity under impacts such as rainfall and water flow fluctuations, and whether the reinforcement effect of vegetation provides adequate soil stabilization over time. As an important indicator for evaluating the protective effect of ecological slope protection, stability assessment of ecological slope protection is a necessary prerequisite for ensuring the safety of ecological slope protection projects, optimizing design, and mitigating risks.

[0004] The limit equilibrium method is currently the most commonly used method for assessing the stability of ecological slope protection. It treats the slope as a rigid body and comprehensively evaluates the stability of the ecological slope protection by analyzing the ratio of the resisting force to the sliding force on the potential sliding surface, and by quantifying the reinforcing effect of plant roots as an increase in soil shear strength. However, because it relies solely on the peak safety factor under static conditions, it is difficult to accurately quantify the additional cohesion of plant roots under dynamic water level impacts. Furthermore, the water absorption of plant roots at different water levels affects the soil moisture content, thus influencing the hydrological effect of pore water pressure on the slope. The limit equilibrium method cannot reflect this dynamic effect over time, nor can it adequately handle the spatially uneven distribution of roots, leading to inaccuracies in assessing the stability of ecological slope protection.

[0005] To account for such dynamic changes, existing technologies attempt to combine the limit equilibrium method with the finite element method for numerical analysis. This involves simulating the stress-strain relationship within the slope to analyze the deformation and failure process and calculate the safety factor. However, when determining pore water pressure, the seepage hysteresis effect caused by dynamic water pressure changes affects the calculation of the safety factor, leading to inaccurate stability assessments of ecological slope protection. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a method and system for evaluating the protection effect of ecological slope protection under dynamic water level impact, which solves the problem in the prior art that the calculation of the safety factor is affected by the seepage hysteresis effect caused by dynamic water pressure changes, resulting in inaccurate evaluation of the stability of ecological slope protection.

[0007] Firstly, the paper provides a method for evaluating the effectiveness of ecological slope protection under dynamic water level impact, including:

[0008] Based on the water level monitoring data of the target ecological slope, determine the pore water pressure time history data of each sampling node in the pre-constructed seepage stress coupling model of the target ecological slope;

[0009] Based on the pore water pressure time history data, the direction of water level change relative to the target ecological slope is determined, and the seepage hysteresis correction coefficient of the pore water pressure time history data is determined according to the direction of water level change.

[0010] Determine the water absorption rate parameters of the plant root system of the target ecological slope under dynamic water level, and correct the pore water pressure time history data of each sampling node based on the water absorption rate parameters and the seepage hysteresis correction coefficient.

[0011] Based on the corrected pore water pressure time history data, a corresponding corrected pore water pressure field is generated, and the safety factor time history curve of the sampling node under dynamic water level impact is calculated based on the plant root parameters of the target ecological slope and the corrected pore water pressure field.

[0012] The stability of the target ecological slope protection is determined based on the time history curve of the safety factor of each sampling node.

[0013] Secondly, this application provides an ecological slope protection effect evaluation system under dynamic water level impact, including a processor and a memory; wherein, the memory stores a computer program, which is used by the processor to load and execute the ecological slope protection effect evaluation method under dynamic water level impact as described in any one of the first aspects.

[0014] In the ecological slope protection effect evaluation method and system under dynamic water level impact in this embodiment, the pore water pressure time history data of each sampling node retains the spatial heterogeneity and time lag information of the pore water pressure response inside the slope. The seepage field analysis is upgraded from a static section to a dynamic time domain process. The pore water pressure response time sequence determines the direction of water level change and generates directionally independent seepage lag correction coefficients, thereby avoiding inaccurate evaluations caused by seepage lag during the water level rise phase and seepage-induced sliding during the water level fall phase. Then, the root water absorption rate parameter under dynamic water level is introduced. Together with the seepage hysteresis correction coefficient, the pore water pressure time history data is corrected, avoiding the limitation of simplifying plant roots to static additional cohesion and ignoring their hydrological effects. At the same time, the generated safety factor time history curve can capture the dynamic migration of the sliding surface with water level changes. Finally, based on the safety factor time history curve, the stability of the target ecological slope is evaluated as a whole. This solves the problem of inaccurate safety factor caused by ignoring the seepage hysteresis direction and missing root hydrological effects in the stability assessment of ecological slopes under dynamic water level impact, and improves the authenticity and reliability of the stability assessment of the target ecological slope. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the process for evaluating the ecological slope protection effect under dynamic water level impact in the embodiments of this application.

[0017] Figure 2 This is a schematic geological profile of the ecological slope protection under the condition of foot reinforcement in the embodiments of this application.

[0018] Figure 3 This is a schematic geological profile of the ecological slope protection under seepage-induced sliding phenomenon in the embodiments of this application. Detailed Implementation

[0019] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0021] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0022] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.

[0023] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0024] like Figure 1 As shown in the figure, this embodiment provides a method for evaluating the ecological slope protection effect under dynamic water level impact, including:

[0025] Step S100: Determine the pore water pressure time history data of each sampling node in the pre-constructed seepage stress coupling model of the target ecological slope based on the water level monitoring data of the target ecological slope;

[0026] Step S200: Determine the direction of water level change relative to the target ecological slope protection based on the pore water pressure time history data, and determine the seepage hysteresis correction coefficient of the pore water pressure time history data according to the direction of water level change;

[0027] Step S300: Determine the water absorption rate parameters of the plant roots of the target ecological slope under dynamic water level, and correct the pore water pressure time history data of each sampling node based on the water absorption rate parameters and the seepage hysteresis correction coefficient.

[0028] Step S400: Generate a corresponding corrected pore water pressure field based on the corrected pore water pressure time history data, and calculate the safety factor time history curve of the sampling node under dynamic water level impact based on the plant root parameters of the target ecological slope and the corrected pore water pressure field.

[0029] Step S500: Determine the stability of the target ecological slope protection based on the safety factor time history curve of each sampling node.

[0030] In this embodiment of the method for evaluating the ecological slope protection effect under dynamic water level impact, the pore water pressure time history data of each sampling node retains the spatial heterogeneity and time lag information of the pore water pressure response inside the slope. This upgrades the seepage field analysis from a static cross-section to a dynamic time-domain process. The pore water pressure response time sequence determines the direction of water level change and generates directionally independent seepage lag correction coefficients, thereby avoiding inaccurate evaluations caused by seepage lag during the water level rise phase and seepage-induced slippage during the water level fall phase. Then, the root water absorption rate parameter under dynamic water level is introduced, along with... The seepage lag correction coefficient is used to correct the pore water pressure time history data, avoiding the limitation of simplifying plant roots as static additional cohesion and ignoring their hydrological effects. At the same time, it enables the generation of safety factor time history curves to capture the dynamic migration of the sliding surface with water level changes. Finally, based on the safety factor time history curves, the stability of the target ecological slope is evaluated as a whole. This solves the problem of inaccurate safety factors caused by ignoring the seepage lag direction and missing root hydrological effects in the stability assessment of ecological slopes under dynamic water level impact, and improves the authenticity and reliability of the stability assessment of the target ecological slope.

[0031] like Figure 2 As shown, during the rising water level phase, a rapid rise in water level easily causes foot-stabilization, where the water flow quickly submerges the slope toe, applying normal hydrostatic pressure inwards onto the slope surface. This normal hydrostatic pressure creates lateral constraint on the potentially sliding slope, effectively increasing the anti-sliding moment and thus raising the safety factor in stability calculations. However, due to the limitation of the slope's permeability coefficient, the high water head pressure brought by the rising water level is delayed in its transmission to the interior of the slope, causing a seepage hysteresis effect. At this time, the pore water pressure at the deep sliding surface inside the slope does not rise synchronously, and the effective stress does not decrease, resulting in normal hydrostatic pressure dominating. Using a steady-state assumption or a uniform correction would exaggerate the seepage hysteresis effect caused by foot-stabilization, leading to a false peak increase in the safety factor and underestimating the actual risk of instability.

[0032] like Figure 3As shown, during the water level decline phase, a rapid drop in water level easily triggers seepage-induced sliding. External hydrostatic pressure is quickly relieved, and slope constraints disappear. However, a seepage lag effect exists within the slope, and high pore water pressure has not yet dissipated, forming a pore water pressure and hydraulic gradient pointing outward from the slope. This creates outward seepage force, which effectively increases the sliding driving force. Simultaneously, high pore water pressure reduces the effective stress on the sliding surface, directly weakening shear strength. The combined effect of the sliding driving force and the reduction in effective stress on the sliding surface causes the shallow sliding surface to migrate upward from the middle and lower slopes, easily triggering shallow landslides. Using a steady-state assumption or a unified correction would also reduce the seepage lag effect caused by seepage-induced sliding, leading to a drastically inflated safety factor and an underestimation of the actual instability risk.

[0033] Step S100: Determine the pore water pressure time history data of each sampling node in the pre-constructed seepage stress coupling model of the target ecological slope based on the water level monitoring data of the target ecological slope.

[0034] Water level monitoring data for the target ecological slope protection refers to time-series data on the change of water level elevation over time in the water area where the target ecological slope protection is located, continuously collected at a predetermined sampling frequency using monitoring equipment such as water level gauges. This data covers the complete water level rise and fall cycle, including monitoring data during both the rising and falling phases. Water level elevation time series and water level change rate time series can be extracted from the water level monitoring data.

[0035] The seepage-stress coupling model refers to a computational model based on the finite element method that can simultaneously solve the seepage field and stress field inside a slope, simulating the dynamic evolution of the seepage field and stress field inside a slope under water level fluctuations. The seepage-stress coupling model can be established using the following method: First, a two-dimensional finite element geometric model is established based on the geological cross-sectional data of the target ecological slope and meshed. Then, each material partition in the two-dimensional finite element geometric model is assigned mechanical parameters including elastic modulus, Poisson's ratio, density, cohesion, and internal friction angle, as well as unsaturated seepage parameters including saturated permeability coefficient, soil-water characteristic curve, and permeability function. Next, a steady-state seepage analysis is performed on the two-dimensional finite element geometric model using preset mechanical and hydrological boundary conditions to obtain the initial pore water pressure distribution and initial groundwater level. Finally, based on the initial pore water pressure distribution and initial groundwater level as the initial conditions for transient analysis, a seepage-stress coupling numerical model is generated to solve the transient response under dynamic water level boundary conditions. Given that the concept of combining the limit equilibrium method with the finite element method to establish an analysis model is relatively mature, the above steps can roughly explain the process of establishing the seepage stress coupling model. Therefore, this embodiment will not go into too much detail about the specific establishment of the seepage stress coupling model.

[0036] Sampling nodes refer to the corner points of the finite element mesh elements formed during the spatial discretization process of the seepage stress coupling model. These sampling nodes are distributed across the entire slope cross-section, including surface nodes, internal nodes, and bottom and side boundary nodes. In this scheme, to preserve the spatial heterogeneity of pore water pressure response at different depths on the slope surface and within the slope, sampling nodes refer to the corner points of the internal slope region.

[0037] Pore ​​water pressure time history data refers to the data sequence formed by arranging the pore water pressure values ​​corresponding to each sampling node at different time steps in the transient seepage analysis process of the seepage stress coupling model. The transient analysis is solved progressively in units of time steps, and the hydraulic head value at each node is recorded at each time step and converted into a pore water pressure value. The pore water pressure time history data of a single sampling node reflects the response curve of pore water pressure at that spatial location with changes in external water level. The pore water pressure time history data of all sampling nodes can constitute complete spatiotemporal evolution information of the pore water pressure field.

[0038] In one embodiment, determining the pore water pressure time history data of each sampling node in a pre-constructed seepage stress coupling model of the target ecological slope based on the water level monitoring data of the target ecological slope specifically includes:

[0039] Step S101: Extract the water level elevation time series and water level change time series from the water level monitoring data, and generate a first water level boundary function and a second water level boundary function based on the water level elevation time series and the water level change time series; the first water level boundary function corresponds to the water level rising stage, and the second water level boundary function corresponds to the water level falling stage.

[0040] A water level elevation time series refers to a sequence of water level elevation values ​​collected continuously by a water level gauge at a predetermined sampling frequency and arranged in chronological order. Changes in water level elevation values ​​can be used to determine the water level changes over time in the area where the target ecological slope protection is located. When extracting the water level elevation time series, the sampling time and the corresponding water level elevation value can be extracted from the water level monitoring data, forming a data set consisting of a timestamp and the water level elevation value {( 、( ... ( } is the time series of water level elevations, where For the i-th sampling time, Let be the water level elevation value corresponding to the i-th sampling time. Preferably, during the extraction process, to ensure that the time series is continuously distributed at equal intervals on the time axis, the original data can be preprocessed, such as removing outliers and performing linear interpolation to fill in missing times.

[0041] A water level change time series refers to a sequence of water level change rate values ​​calculated hourly based on a water level elevation time series and arranged in chronological order, i.e. { , … },in Let be the rate of water level change at time i. The speed of water level rise or fall at each time point can be determined based on the change in the rate of water level change value. To ensure consistency in data processing, the collected water level change time series and water level elevation time series share the same time base and number of sampling points. When extracting the water level change time series, based on the extracted water level elevation time series, the formula can be used... The rate of water level change between two adjacent sampling times is calculated point by point. A positive value for the rate of water level change indicates a rising water level; conversely, a negative value indicates a falling water level. By traversing the entire water level change time series, the entire monitoring period can be divided into multiple water level rising and falling phases based on the positive or negative value of the rate of water level change at each time point.

[0042] When generating the first and second water level boundary functions, function fitting can be used to fit the water level change time series for each water level rise and fall segment, with the sampling time as the independent variable and the water level elevation as the dependent variable. This fitting process forms the corresponding first and second water level boundary functions. Preferably, during function fitting, interpolation can be used to adjust the smoothness of the data and reduce the errors in the fitted first and second water level boundary functions.

[0043] Step S102: Construct dynamic water level boundary conditions based on the first water level boundary function and the second water level boundary function, input the dynamic water level boundary conditions into the seepage stress coupling model for transient analysis, and obtain the pore water pressure time history data of each sampling node.

[0044] When constructing dynamic water level boundary conditions, the first and second water level boundary functions can be converted into total head versus time-related data for the sampling nodes at the corresponding water level change stages. This total head versus time-related data is then used as the dynamic water level boundary conditions for the corresponding sampling nodes in the seepage stress coupling model. Specifically, during the water level rise phase, the dynamic water level boundary conditions increase with water level elevation; during the water level fall phase, they decrease with water level elevation. When setting dynamic water level boundary conditions in the seepage stress coupling model, all sampling nodes located on the slope must be selected. This allows the seepage stress coupling model to automatically read the current total head value at each time step during calculation and allocate this value to all sampling nodes as boundary conditions. Due to the spatial discreteness of the finite element model, slope nodes and internal nodes at different depths each have independent pore water pressure calculation results. Arranging these results in chronological order forms the pore water pressure time history data for each sampling node, recording the complete response trajectory of pore water pressure at each spatial location as it changes with the external water level.

[0045] During transient analysis, the seepage-stress coupling model uses the initial pore water pressure distribution and initial groundwater level obtained from steady-state analysis as initial conditions, and the dynamic water level boundary conditions as external potential driving conditions. Starting from the initial moment, the calculation proceeds hourly according to a preset time step. Within each time step, the seepage equation and mechanical equilibrium equation are solved simultaneously, outputting the pore water pressure, displacement, and stress values ​​of each node at that moment. After the transient analysis is completed, nodes located inside the slope but not on the slope surface or at the bottom boundary are used as sampling nodes, and the pore water pressure values ​​of each sampling node at all time steps are extracted from the output results. Arranging the pore water pressure time history data of each node in chronological order makes the pore water pressure changes of the internal nodes of the slope lag behind the slope surface nodes and water level boundary function on the time axis. This can reflect the response delay caused by the lag of the internal pore water pressure response of the slope due to the limited permeability coefficient of the soil, which is caused by the external water level change. In this way, the non-uniform spatial distribution of pore water pressure of the target ecological slope under dynamic water level impact is preserved, which makes it easier for subsequent stability calculations to be based on the real unsteady seepage state rather than the simplified assumption of the unsteady seepage state.

[0046] Step S200: Determine the direction of water level change relative to the target ecological slope based on the pore water pressure time history data, and determine the seepage hysteresis correction coefficient of the pore water pressure time history data according to the direction of water level change.

[0047] The direction of water level change refers to the direction of water level variation based on the actual response state of the seepage field inside the slope, rather than the rise or fall of the water area where the target ecological slope protection is located. By comparing the pore water pressure response time series of slope surface nodes and preset depth nodes inside the slope, it can be determined whether the external water level change has been transmitted to the inside of the slope and the extent of transmission, thereby determining the direction of water level change relative to the seepage state of the slope at the current moment.

[0048] Specifically, determining the direction of water level change relative to the target ecological slope based on the pore water pressure time history data includes:

[0049] Step S201: Obtain the first pore water pressure time series of the sampling node at the preset slope position and the second pore water pressure time series at the preset depth inside the slope in the seepage stress coupling model, and determine the difference sequence between the first pore water pressure time series and the second pore water pressure time series at the same time.

[0050] Step S202: When the average value of the difference sequence within a preset time window is greater than zero, the water level change direction information is determined to be the direction of water level rise;

[0051] Step S203: When the average value of the difference sequence within a preset time window is less than zero, the water level change direction information is determined to be the direction of water level decline.

[0052] In steps S201-S203, the direction of water level change is not determined by a simple positive or negative judgment based on external water level monitoring data, but rather by the actual response state of the seepage field inside the slope. Under conditions of significant seepage hysteresis, the external water level may have changed from rising to falling, but the slope interior may still be in a state of pore water pressure accumulation. In this case, the direction of water level change is determined to be falling rather than rising. For example, when the water flow impacting the target ecological slope is large and rapid, the external water level has already risen, but the internal pore water pressure has not yet risen. However, the pore water pressure at the sampling node is higher than the internal pore water pressure, so this is determined to be a rising water level. Similarly, when the water impacting the target ecological slope drops rapidly, the external water level has already decreased, but the internal pore water pressure has not yet dissipated. However, the pore water pressure at the sampling node is higher than the slope pore water pressure, so this is determined to be a falling water level.

[0053] The seepage hysteresis correction factor includes a first seepage hysteresis correction factor corresponding to the rising water level phase and a second seepage hysteresis correction factor corresponding to the falling water level phase.

[0054] During the rising water level phase, the external hydrostatic pressure increases, while the pore water pressure inside the slope lags behind and does not respond synchronously, forming a hydraulic gradient from the slope surface inwards. Steady-state calculations may overestimate the buoyancy force inside the slope, resulting in an underestimation of the effective stress and an artificially high safety factor. By introducing a first correction factor to calculate the reduction in pore water pressure during this phase, the risk of instability can be avoided by prematurely incorporating high buoyancy forces, thus reducing the safety factor to the normal range.

[0055] During the water level decline phase, the external hydrostatic pressure has been relieved, but the high pore water pressure inside the slope remains due to lag, forming a hydraulic gradient from inside the slope outwards. Steady-state calculations tend to overestimate the degree of pore water pressure dissipation, leading to higher calculated effective stress and an artificially inflated safety factor. By introducing a second correction factor to calculate the extent to which the pore water pressure dissipation should be delayed during this phase, the excess pore water pressure generated by the lag can be forcibly retained, resulting in a more accurate calculation of shear strength.

[0056] In one embodiment, determining the seepage hysteresis correction coefficient of the pore water pressure time history data based on the direction of water level change specifically includes:

[0057] Step S204: When the water level change direction is the rising direction, determine the first hydraulic gradient from the slope surface to the inside of the slope based on the pore water pressure time history data; when the water level change direction is the falling direction, determine the second hydraulic gradient from the inside of the slope to the outside of the slope based on the pore water pressure time history data.

[0058] The first hydraulic gradient refers to the head driving force formed during a water level rise, due to the external water level increasing while the internal pore water pressure fails to keep pace. It can be expressed by the formula... Determine the first hydraulic gradient ,in and These represent the pore water pressure values ​​at preset locations on the slope surface and the pore water pressure values ​​at preset depths within the corresponding slope at the same time. The distance between the preset position node and the preset depth node.

[0059] Similarly, the second hydraulic gradient refers to the head driving force formed during the water level drop because the internal high pore water pressure has not yet dissipated while the external water level has decreased. This can be expressed by the formula... Determine the second hydraulic gradient .

[0060] Step S205: Obtain the saturated permeability coefficient of the target ecological slope, and extract the first water level change rate during the water level rise phase and the second water level change rate during the water level fall phase from the water level monitoring data.

[0061] The saturated permeability coefficient refers to the ability of water to flow along the hydraulic gradient within the pores of soil when the pores are completely filled. A higher value indicates greater soil permeability, while a lower value indicates lower permeability. The saturated permeability coefficient can be determined by drilling and water injection tests on the target ecological slope, or by taking samples from the target ecological slope and conducting permeability tests.

[0062] The first rate of water level change refers to the rate of change of water level elevation during the rising phase, extracted from water level monitoring data. It can be obtained by linearly fitting the water level elevation time series during the rising phase. Similarly, the second rate of water level change refers to the rate of change of water level elevation during the falling phase, extracted from water level monitoring data. It can also be obtained by linearly fitting the water level elevation time series during the falling phase.

[0063] Step S206: Determine a first hysteresis parameter based on the ratio of the first water level change rate to the saturated permeability coefficient, and determine a second hysteresis parameter based on the ratio of the second water level change rate to the saturated permeability coefficient.

[0064] The first hysteresis parameter reflects the relative magnitude of the rate of water level rise to the soil's permeability. A larger value indicates a smaller reduction in pore pressure, and thus a more significant seepage hysteresis effect during the water level rise phase. Similarly, the second hysteresis parameter reflects the relative magnitude of the rate of water level fall to the soil's permeability. A larger value indicates a greater amount of pore pressure dissipation needs to be delayed, and thus a more significant seepage hysteresis effect during the water level fall phase.

[0065] Step S207: Determine the first seepage hysteresis correction coefficient based on the first hydraulic gradient and the first hysteresis parameter.

[0066] According to the formula Determine the first seepage hysteresis correction factor ,in This is the first lag parameter.

[0067] Step S208: Determine the second seepage hysteresis correction coefficient based on the second hydraulic gradient and the second hysteresis parameter.

[0068] Similarly, it can be done according to the formula Determine the second seepage hysteresis correction factor ,in This is the second lag parameter.

[0069] In steps S201-S208, by introducing a seepage hysteresis correction coefficient, the original pore water pressure value obtained from transient seepage analysis can be corrected to a transient response value that is closer to the physical reality, thus eliminating the calculation deviation caused by the hysteresis effect of the pore water pressure response inside the slope lagging behind the external water level change due to the limited permeability coefficient of the soil.

[0070] Step S300: Determine the water absorption rate parameter of the plant root system of the target ecological slope under dynamic water level, and correct the pore water pressure time history data of each sampling node based on the water absorption rate parameter and the seepage hysteresis correction coefficient.

[0071] The water absorption rate parameter refers to the volume of water absorbed and expelled from the soil by plant roots per unit volume of soil per unit time. It can indicate the active regulation ability of plant roots on the local moisture content and pore water pressure of the slope.

[0072] In one embodiment, determining the water absorption rate parameter of the plant roots of the target ecological slope protection under dynamic water level specifically includes:

[0073] Step S301: Obtain the root distribution depth, root density distribution, and root water absorption characteristic curve of the target ecological slope.

[0074] The root distribution depth of the target ecological slope protection refers to the maximum depth to which the plant roots extend vertically downwards from the ground surface. It can be determined based on the growth characteristics of the plants planted on the target ecological slope protection and statistical values ​​from on-site plant samples.

[0075] Root density distribution refers to the distribution function of the total length of plant roots per unit volume of soil with depth. The root length in soil samples at each depth layer can be determined based on the growth characteristics of the plants planted in the target ecological slope protection area and statistical values ​​from on-site plant sampling. This root length is then divided by the soil sample volume to obtain the root density value for each depth layer. Generally, the higher the root density, the stronger the water absorption capacity of the plant roots at that depth layer, and the more significant the regulatory effect on pore water pressure.

[0076] The root water absorption characteristic curve is a curve used to describe the functional relationship between the water absorption rate of plant roots and the suction of the soil matrix. It can be obtained by sampling at multiple points on the target ecological slope and measuring the water absorption rate of plant roots and the soil matrix suction at each sampling point. The root water absorption characteristic curve function can then be obtained by performing nonlinear regression fitting on the data from each sampling point. Generally, when the matrix suction is low, the soil moisture is high, resulting in a high water absorption rate. Conversely, as the matrix suction increases, the soil gradually dries out, and the water absorption rate of plant roots gradually increases.

[0077] Step S302: Divide the slope into multiple root influence layers according to the root distribution depth, and determine the unit volume water absorption rate of each root influence layer under multiple preset matrix suction conditions according to the root density distribution and the root water absorption characteristic curve.

[0078] The root influence layer refers to multiple independent computational layers in the vertical direction of a slope, based on the depth of plant root distribution. Each influence layer has a relatively uniform root density distribution. It can be divided according to root density gradients, with denser layers in areas of larger gradients and fewer layers in areas of smaller gradients.

[0079] Preset matrix suction conditions refer to a set of discrete matrix suction points selected in advance when constructing the unit volume water absorption rate of the root influence layer. These points are used to determine the water absorption capacity of each influence layer under different moisture conditions. These discrete points cover the matrix suction range from saturation to near the wilting point, such as 0 kPa, 10 kPa, 20 kPa, 50 kPa, and 100 kPa. By calculating the unit volume water absorption rate at these discrete matrix suction points, a mapping table between the unit volume water absorption rate and matrix suction of each root influence layer can be constructed, allowing for direct use of the mapping table to determine the unit volume water absorption rate of each root influence layer.

[0080] When determining the unit volume water absorption rate of each root system influence layer under multiple preset matrix suction conditions, the slope can be divided into multiple root system influence layers vertically from the slope surface, with the root distribution depth as the lower boundary. For each root system influence layer, the average root density within the depth range of that layer is taken as the root density value of that layer. The root water absorption characteristic curve is read, and the corresponding single root water absorption rate is read under the preset matrix suction conditions. Then, based on the root density distribution, the number of roots per unit volume in that influence layer is determined. Finally, multiplying the single root water absorption rate by the number of roots per unit volume yields the unit volume water absorption rate of that root system influence layer under each preset matrix suction condition.

[0081] Step S303: Determine the matrix suction value of each root-affected layer at different times based on the pore water pressure time history data.

[0082] The matrix suction value refers to the difference between the pore water pressure in the soil and the atmospheric pressure. When determining the matrix suction value of each root-affected layer at different times, the pore water pressure values ​​of each sampling node within each root-affected layer at each time can be read from the pore water pressure time-history data obtained in step S100. For each root-affected layer, the average pore water pressure of all sampling nodes within that layer's depth range is taken as the representative pore water pressure value for that layer. Finally, the matrix suction values ​​of each affected layer at each time can be arranged in chronological order to form the matrix suction time-history data for each affected layer. This converts the pore water pressure data into a physical driving force that the plant can respond to, allowing the water absorption rate parameter to reflect the actual impact of external water level changes on root water absorption behavior.

[0083] Step S304: Generate the water absorption rate parameter based on the unit volume water absorption rate of each root-affected layer and the matrix suction value at different times.

[0084] When traversing each root-affected layer and the current matrix suction value at each moment, the matrix suction value at the current moment can be determined through a unit volume water absorption rate mapping table. When the matrix suction value is exactly equal to a certain discrete value in the preset conditions, the unit volume water absorption rate corresponding to that discrete value is directly read as the unit volume water absorption rate of that root-affected layer; when the matrix suction value is between two preset discrete values, the corresponding unit volume water absorption rate can be calculated using linear interpolation, and the interpolated unit volume water absorption rate value is used as the water absorption rate parameter value of that root-affected layer. The water absorption rate parameter values ​​of each root-affected layer at each moment constitute complete water absorption rate parameter time history data, which serves as the input for correcting the pore water pressure at each sampling node.

[0085] In one embodiment, generating a corresponding corrected pore water pressure field based on the corrected pore water pressure time history data specifically includes:

[0086] Step S305: Determine the matrix suction value of each sampling node in the root influence layer, and match the corresponding unit volume water absorption rate from the water absorption rate parameters based on the matrix suction value of the sampling node.

[0087] The matrix suction value can be obtained by converting the pore water pressure time history data of the sampling nodes. When the pore water pressure is negative, the matrix suction value is the absolute value of the pore water pressure value; when the pore water pressure is positive, the matrix suction value is zero. The obtained matrix suction value is then used as a lookup index to match the water absorption rate per unit volume with the matrix suction mapping table. If the current matrix suction value is exactly equal to a preset discrete value in the mapping table, the corresponding water absorption rate per unit volume is directly read; if the current matrix suction value is between two preset discrete values, linear interpolation is used to calculate the water absorption rate per unit volume corresponding to that matrix suction. After matching, each sampling node has a corresponding water absorption rate per unit volume at the current time.

[0088] Step S306: Calculate the amount of water discharged from the corresponding sampling node per unit time based on the matching water absorption rate per unit volume, and update the volumetric water content of the corresponding sampling node based on the amount of water discharged.

[0089] Water excretion Through formula Confirmed, among which This represents the corresponding water absorption rate per unit volume. This refers to the duration corresponding to a unit of time.

[0090] Then, the pore water pressure is used to determine whether the sampling node is in an unsaturated state. If the pore water pressure is greater than or equal to zero, the sampling node is currently in a saturated state. In this state, the soil moisture content has reached its upper limit, and root water absorption only removes water from the soil without changing the volumetric moisture content value; therefore, no moisture content update is performed. If the pore water pressure is less than zero, the sampling node is currently in an unsaturated state. The current volumetric moisture content is obtained by subtracting the amount of water discharged from the volumetric moisture content of the sampling node at the end of the previous unit time.

[0091] Step S307: Recalculate the pore water pressure value of the corresponding sampling node based on the updated volumetric water content and generate the corrected pore water pressure field.

[0092] After updating the volumetric water content, the root water absorption characteristic curve from step S301 is inversely calculated. The updated volumetric water content is substituted into the inverse function of the root water absorption characteristic curve to calculate the corresponding matrix suction value. Then, the saturation state of the sampling node is converted into pore water pressure. In the unsaturated state, the pore water pressure is negative and is the opposite of the matrix suction value; while in the saturated state, the pore water pressure is determined based on the hydrostatic pressure distribution.

[0093] When generating the corrected pore water pressure field, the pore water pressure values ​​recalculated at each sampling node at each time step can be organized according to spatial location and temporal order to form a discrete data set covering the entire slope computational domain. Then, steps S305 to S307 are repeated for all sampling nodes within all root influence layers, and the discrete data set contains the recalculated pore water pressure values ​​of all sampling nodes.

[0094] In steps S301-S307, the water absorption behavior of plant roots is upgraded from a static empirical description to a dynamic water level-driven node-by-node quantitative correction, which upgrades plants from passive reinforcement materials to active hydrological regulators in ecological slope protection assessment. At the same time, it forms a dual correction mechanism with seepage hysteresis correction, so that the corrected pore water pressure field can reflect the dynamic hydrological feedback of the root system in both spatial distribution and temporal evolution.

[0095] In one embodiment, the calculation of the safety factor time history curve of the sampling node under dynamic water level impact based on the plant root parameters of the target ecological slope and the modified pore water pressure field specifically includes:

[0096] Step S401: Determine the effective stress distribution at each moment based on the modified pore water pressure field.

[0097] Effective stress distribution refers to the spatial distribution of effective stress values ​​at various locations within the slope. The pore water pressure values ​​at each node at each time point can be extracted based on the modified pore water pressure field. The total stress value at the same sampling node at the same time point can be determined from the total stress calculation results of the seepage-stress coupling model. The effective stress value at that sampling node is then the difference between the total stress value and the pore water pressure value. Calculating the effective stress value at each sampling node separately determines the effective stress distribution of the target ecological slope protection at that time point.

[0098] Correcting the pore water pressure value directly affects the calculation of the effective stress value. Generally speaking, for every corresponding decrease in the corrected pore water pressure value, the effective stress value increases by the same amount, thus increasing the shear strength of the sampling node. Conversely, for every corresponding increase in the pore water pressure value, the effective stress value decreases by the same amount, thus decreasing the shear strength of the sampling node.

[0099] Step S402: Calculate the additional cohesion of the root system based on the root tensile strength and root area ratio in the plant root system parameters, and superimpose the additional cohesion of the root system onto the soil cohesion of the target ecological slope protection to generate the reinforced soil cohesion.

[0100] Root tensile strength refers to the maximum tensile force that a plant root system can withstand per unit cross-sectional area under axial tension. Root tensile strength can be determined based on the growth characteristics of the plants planted in the target ecological slope protection and the tensile test of plants sampled on site.

[0101] The root area ratio refers to the proportion of the cross-sectional area of ​​the root system on a unit area shear surface. It can be determined by collecting soil samples containing roots at sampling points, separating the roots by washing, measuring the total cross-sectional area of ​​the roots on the shear surface using an image analyzer, and dividing it by the total area of ​​the shear surface.

[0102] Root cohesion refers to the equivalent increase in shear strength of the soil by which plant roots add cohesion to the inherent cohesion of the soil. It can be expressed by the formula... Confirmed, among which Add cohesion to the root system The root damage coefficient ranges from 0.2 to 2. This represents the root area ratio.

[0103] The soil cohesion of a target ecological slope protection unit refers to the inherent cohesion parameter of the soil in the slope before root reinforcement. It can be determined by sampling the target ecological slope and performing shear tests. The soil cohesion after reinforcement... Through formula Confirmed, among which Soil cohesion for ecological slope protection.

[0104] Step S403: Based on the strength reduction method and the time-by-time method, determine the safety factor of the target ecological slope protection according to the cohesion of the reinforced soil and the effective stress distribution.

[0105] The strength reduction method is a time-by-time iterative solution method based on the finite element strength reduction method.

[0106] In one embodiment, the time-by-time method based on the strength reduction method, which determines the safety factor of the target ecological slope protection according to the cohesion of the reinforced soil and the effective stress distribution, specifically includes:

[0107] Step S4031: Determine the target time and determine the effective stress distribution under the modified pore water pressure field corresponding to the target time.

[0108] The target time can be selected from the complete time interval of the safety factor time history curve before the safety factor is calculated. The corrected pore water pressure values ​​of each sampling node inside the slope at this target time are extracted. Then, the total stress value at the same sampling node at the same time is determined. The effective stress value is determined by the difference between the total stress value and the corrected pore water pressure value. Finally, the effective stress values ​​of all nodes are set according to spatial coordinates as the effective stress distribution field at that time.

[0109] Step S4032: Obtain the regional geological parameters of the target ecological slope protection, and extract the soil internal friction angle from the regional geological parameters.

[0110] Regional geological parameters refer to a set of quantitative indicators describing the physical, mechanical, and hydraulic properties of the geological body at the site of the target ecological slope protection. These parameters can be assigned to various materials in the model when modeling a seepage-stress coupling model. Typically, regional geological parameters include mechanical parameters such as cohesion and internal friction angle, seepage parameters such as saturated permeability coefficient, and model parameters such as yield criterion.

[0111] Step S4033: Gradually reduce the cohesion and internal friction angle of the reinforced soil until the plastic strain region of the seepage stress coupling model is completed.

[0112] Step S4034: Determine the reduction factor when the plastic strain region is being penetrated as the safety factor at the target time.

[0113] Using the cohesion and effective stress distribution of the reinforced soil as input, and setting the initial value of the reduction coefficient F to 1, the process enters a reduction iteration loop. In each iteration, the formula is used to... Determine the soil cohesion after iteration and internal friction angle ,in The soil cohesion is given by k, where k is the number of iterations. It is the original internal friction angle of the soil and can be determined by shearing tests on soil samples collected from the target ecological slope.

[0114] After one iteration, based on the reduced soil cohesion and internal friction angle Recalculate the plastic strain distribution of the slope under the reduction factor, and check whether the plastic strain region has been extended from the toe to the crest. If not, increase the reduction factor and continue iterating; if it has been extended, terminate the iteration cycle and record the current reduction factor as the safety factor at that moment.

[0115] Step S4035: Reselect the target time and traverse all times of the safety factor time history curve to obtain the safety factor corresponding to all times of the safety factor time history curve.

[0116] Once the safety factor for the previous target time is determined, the next uncalculated time in the safety factor time history curve is selected as the new target time. Steps S4031-S4034 are repeated until the safety factor calculation has been completed for all times covered by the safety factor time history curve.

[0117] Step S404: Arrange the safety factors at each time point in chronological order to generate the safety factor time history curve.

[0118] After determining the safety factor value at each time point, the timestamp of each time point and the corresponding safety factor value are combined into a pairwise data set. The data set is arranged in ascending order of time, and a safety factor evolution curve covering the entire monitoring period is generated with time as the horizontal axis and safety factor as the vertical axis.

[0119] In steps S401-S404, the safety factor is determined by the strength reduction method and the time-by-time method. There is no need to pre-set the sliding surface that is prone to displacement under dynamic water level impact. The most dangerous failure mode of the slope at the current moment can be directly determined based on whether the plastic strain region is connected. The independent iteration at each time moment ensures that the safety factor at each time moment is not affected by the calculation results of adjacent time moments, and eliminates the error caused by data coupling between time steps.

[0120] Step S500: Determine the stability of the target ecological slope protection based on the safety factor time history curve of each sampling node.

[0121] Since each sampling node is located in a different spatial position, with different burial depths, distances from the slope, distances from the water level, and relative orientations to the slope, the sampling nodes in different spatial positions are affected differently by the dynamic water flow impact. Considering the safety factor time history curve of each sampling node, it is possible to locate the weak spatial position in the slope that first reaches the critical state of instability.

[0122] Furthermore, when determining slope instability by checking the continuity of the plastic strain zone using the strength reduction method and time-by-time method, the path from the slope toe to the slope crest that completes first depends on the effective stress distribution and strength parameters at various spatial locations within the slope. The safety factor of different sampling nodes reflects the relationship between the local stress state and strength reserve at that node's location. A group of nodes with lower safety factors constitutes the spatial trajectory of the potential sliding surface. By examining the safety factors of each sampling node, the spatial path formed by the nodes with the lowest safety factors can be identified, corresponding to the location of the most dangerous sliding surface, thus effectively capturing the dynamic migration of the sliding surface location under dynamic water flow impact.

[0123] In one embodiment, determining the stability of the target ecological slope protection based on the safety factor time history curves of each of the sampling nodes specifically includes:

[0124] Step S501: Extract the peak value, valley value, peak occurrence time, and valley occurrence time from the safety factor time history curve.

[0125] The peak safety factor refers to the maximum value reached by the safety factor time history curve of a single sampling node during the entire monitoring period. It reflects the moment when the node has the highest stability during dynamic water level impacts. This moment usually occurs in the early stage of a rapid rise in water level, corresponding to the stage where the pressure foot stabilization phenomenon is dominant. The moment when the peak occurs is the moment corresponding to the peak safety factor on the safety factor time history curve.

[0126] The safety factor trough value refers to the minimum value reached by the safety factor time history curve of a single sampling node during the entire monitoring period. It reflects the moment when the node's stability is lowest during dynamic water level fluctuations, typically occurring during the rapid decline of water level or the later stages of sustained high water level operation, corresponding to the stage where seepage-induced sliding is dominant. The moment the trough value occurs is the moment corresponding to the safety factor trough value on the safety factor time history curve.

[0127] By iterating through all safety factor values ​​in the safety factor time history curve dataset, the maximum and minimum values ​​can be found through sequential comparison. The maximum value is the safety factor peak, and the minimum value is the safety factor trough. Furthermore, if multiple moments have the same safety factor value that is either the maximum or minimum, the moment that occurs first is taken as the corresponding peak and trough occurrence times.

[0128] Step S502: Determine the stability fluctuation range based on the difference between the peak value and the valley value of the safety factor.

[0129] Stability fluctuation amplitude is used to describe the degree of drastic fluctuation in the stability of a sampling node throughout the entire monitoring period. Generally, the larger the fluctuation amplitude, the higher the sensitivity of the sampling node at that location to water level changes and the worse its anti-interference ability.

[0130] Step S503: Determine the stability decay rate based on the time interval between the peak occurrence time and the valley occurrence time.

[0131] The stability decay rate describes how quickly the stability of a sampling node deteriorates. Generally, a faster decay rate indicates a more sudden loss of stability at that location due to changes in external water level. This can be expressed by the formula... Confirmed, among which For stability decay rate, For the peak safety factor, The lowest value of the safety factor. The time when the valley value occurs. This represents the peak value. Furthermore, since soil stability typically decreases under dynamic water level impact, if the peak value occurs later than the trough value, it indicates that the safety factor time history curve for that sampling node lacks an upward segment. In this case, the stability decay rate is marked as invalid, and subsequent stability assessments are based directly on the duration of the safety factor of that sampling node being below the preset threshold and the trough value.

[0132] Step S504: Compare the safety factor at each moment in the safety factor time history curve with the preset safety factor threshold, and determine the continuous period when the safety factor is lower than the preset safety factor threshold as the target continuous period.

[0133] The target duration reflects the total exposure time of the sampling node in an unstable or understable state. It can be determined by iterating through the safety factor time history curve of the sampling node, comparing the safety factor at each moment with a preset safety factor threshold, and recording all moments below the threshold. These moments are then arranged chronologically to identify consecutive segments, and the duration of each segment is calculated. The total duration obtained by summing the durations of all consecutive segments is the target duration.

[0134] Step S505: Determine the stability of the target ecological slope protection based on the stability fluctuation amplitude, the stability decay rate, and the target duration.

[0135] Generally, when the stability fluctuation amplitude is less than a preset fluctuation amplitude threshold, the stability decay rate is less than a preset decay rate threshold, and the target duration is zero, the sampling node is considered to be in a stable state under the current dynamic water level impact conditions. Conversely, when the stability fluctuation amplitude is greater than or equal to a preset fluctuation amplitude threshold, the stability decay rate is greater than or equal to a preset decay rate threshold, and the target duration is greater than zero, the sampling node is considered to be in an unstable state under the current dynamic water level impact conditions. Only when all sampling nodes are determined to be in a stable state can the stability of the target ecological slope protection under this dynamic water level impact be assessed as qualified.

[0136] For sampling nodes deemed unstable, further analysis of their spatial distribution characteristics is needed to pinpoint their location on the slope, their depth range, and the water level at which their corresponding valley values ​​occur. These unstable conditions should be categorized, and the reasons for their instability can be analyzed based on the different classification results. For example, sampling nodes where safety factor valley values ​​are concentrated during the rising water level phase can be classified as rising-phase instability sampling nodes; those where safety factor valley values ​​are concentrated during the falling water level phase can be classified as falling-phase instability sampling nodes; and those whose target duration is distributed throughout the entire monitoring period can be classified as continuously low-stability sampling nodes.

[0137] In summary, in this embodiment of the method for evaluating the ecological slope protection effect under dynamic water level impact, on the one hand, by introducing a seepage lag correction coefficient, the original pore water pressure value obtained from transient seepage analysis can be corrected to a transient response value that more closely approximates the physical reality. This eliminates the calculation deviation introduced by the lag effect caused by the limited permeability coefficient of the soil, which causes the pore water pressure response inside the slope to lag behind the external water level change. On the other hand, by determining the safety factor through the strength reduction method and the time-by-time method, there is no need to pre-set a sliding surface that is prone to displacement under dynamic water level impact. The criterion of plastic strain penetration directly determines the most dangerous failure mode of the slope at the current moment. The independent iteration at each time moment ensures that the safety factor at each moment is not affected by the calculation results of adjacent moments, eliminating the error caused by data coupling between time steps. This solves the problem of inaccurate safety factor caused by ignoring the seepage lag direction and lacking root hydrological effects in the stability assessment of ecological slope protection under dynamic water level impact, and improves the authenticity and reliability of the target ecological slope stability assessment.

[0138] Based on the same inventive concept as the above embodiments, this embodiment also provides an ecological slope protection effect evaluation system under dynamic water level impact, including a processor and a memory; wherein, the memory stores a computer program, which is used by the processor to load and execute the ecological slope protection effect evaluation method under dynamic water level impact as described above.

[0139] Based on the same inventive concept as the above embodiments, this embodiment also provides an electronic device, which is provided with a computer-readable storage medium storing instructions for loading and executing the method as described above by a processor.

[0140] The embodiments of the mobile terminal and computer-readable storage medium provided in this application include all the technical features of the embodiments of the above control method. The extended and explanatory content of the specification is basically the same as that of the embodiments of the above method, and will not be repeated here.

[0141] This application also provides a computer program product, which includes computer program code. When the computer program code is run on a computer, it causes the computer to perform the methods described in the various possible implementations above.

[0142] This application also provides a chip, including a memory and a processor. The memory is used to store a computer program, and the processor is used to call and run the computer program from the memory, so that a device with the chip installed performs the methods described in the various possible implementations above.

[0143] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0144] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for evaluating the ecological slope protection effect under dynamic water level impact, characterized in that, include: Based on the water level monitoring data of the target ecological slope, determine the pore water pressure time history data of each sampling node in the pre-constructed seepage stress coupling model of the target ecological slope; Based on the pore water pressure time history data, the direction of water level change relative to the target ecological slope is determined, and the seepage hysteresis correction coefficient of the pore water pressure time history data is determined according to the direction of water level change. Determine the water absorption rate parameters of the plant root system of the target ecological slope under dynamic water level, and correct the pore water pressure time history data of each sampling node based on the water absorption rate parameters and the seepage hysteresis correction coefficient. Based on the corrected pore water pressure time history data, a corresponding corrected pore water pressure field is generated, and the safety factor time history curve of the sampling node under dynamic water level impact is calculated based on the plant root parameters of the target ecological slope and the corrected pore water pressure field. The stability of the target ecological slope protection is determined based on the time history curve of the safety factor of each sampling node.

2. The method for evaluating the ecological slope protection effect under dynamic water level impact as described in claim 1, characterized in that, The determination of pore water pressure time history data at each sampling node of the target ecological slope in the pre-constructed seepage stress coupling model based on water level monitoring data of the target ecological slope specifically includes: The water level elevation time series and water level change time series are extracted from the water level monitoring data, and a first water level boundary function and a second water level boundary function are generated based on the water level elevation time series and the water level change time series; the first water level boundary function corresponds to the water level rising stage, and the second water level boundary function corresponds to the water level falling stage. Dynamic water level boundary conditions are constructed based on the first water level boundary function and the second water level boundary function. The dynamic water level boundary conditions are then input into the seepage stress coupling model for transient analysis to obtain the pore water pressure time history data of each sampling node.

3. The method for evaluating the ecological slope protection effect under dynamic water level impact as described in claim 1, characterized in that, Determining the direction of water level change relative to the target ecological slope based on the pore water pressure time history data specifically includes: The first pore water pressure time series of the sampling node at the preset slope position and the second pore water pressure time series at the preset depth inside the slope are obtained in the seepage stress coupling model, and the difference sequence between the first pore water pressure time series and the second pore water pressure time series at the same time is determined. When the average value of the difference sequence within a preset time window is greater than zero, the water level change direction information is determined to be the direction of water level rise. When the average value of the difference sequence within a preset time window is less than zero, the water level change direction information is determined to be the direction of water level decline.

4. The method for evaluating the ecological slope protection effect under dynamic water level impact as described in claim 3, characterized in that, The seepage hysteresis correction coefficient includes a first seepage hysteresis correction coefficient corresponding to the water level rise phase and a second seepage hysteresis correction coefficient corresponding to the water level fall phase; the step of determining the seepage hysteresis correction coefficient of the pore water pressure time history data based on the water level change direction specifically includes: When the water level change direction is upward, the sampling node is determined from the slope surface to the inside of the slope based on the pore water pressure time history data; when the water level change direction is downward, the sampling node is determined from the inside of the slope to the outside of the slope based on the pore water pressure time history data. The saturated permeability coefficient of the target ecological slope is obtained, and the first water level change rate during the water level rise phase and the second water level change rate during the water level fall phase are extracted from the water level monitoring data. A first hysteresis parameter is determined based on the ratio of the first water level change rate to the saturated permeability coefficient, and a second hysteresis parameter is determined based on the ratio of the second water level change rate to the saturated permeability coefficient. The first seepage hysteresis correction coefficient is determined based on the first hydraulic gradient and the first hysteresis parameter; The second seepage hysteresis correction coefficient is determined based on the second hydraulic gradient and the second hysteresis parameter.

5. The method for evaluating the ecological slope protection effect under dynamic water level impact as described in claim 1, characterized in that, The determination of the water absorption rate parameters of the plant roots of the target ecological slope protection under dynamic water level specifically includes: Obtain the root distribution depth, root density distribution, and root water absorption characteristic curves of the target ecological slope protection. The slope is divided into multiple root influence layers according to the depth of the plant root distribution. The water absorption rate per unit volume of each root influence layer is determined under multiple preset matrix suction conditions based on the root density distribution and the root water absorption characteristic curve. The matrix suction values ​​of each root-affected layer at different times are determined based on the pore water pressure time history data. The water absorption rate parameter is generated based on the unit volume water absorption rate of each root-affected layer and the matrix suction value at different times.

6. The method for evaluating the ecological slope protection effect under dynamic water level impact as described in claim 5, characterized in that, The step of generating a corresponding corrected pore water pressure field based on the corrected pore water pressure time history data specifically includes: Determine the matrix suction value of each sampling node in the root influence layer, and match the corresponding water absorption rate per unit volume from the water absorption rate parameters based on the matrix suction value of the sampling node; The amount of water discharged from the corresponding sampling node per unit time is calculated based on the matching water absorption rate per unit volume, and the volumetric water content of the corresponding sampling node is updated based on the amount of water discharged. The pore water pressure value of the corresponding sampling node is recalculated based on the updated volumetric water content, and the corrected pore water pressure field is generated.

7. The method for evaluating the ecological slope protection effect under dynamic water level impact as described in claim 1, characterized in that, The calculation of the safety factor time history curve of the sampling node under dynamic water level impact based on the plant root parameters of the target ecological slope and the modified pore water pressure field specifically includes: The effective stress distribution at each moment is determined based on the modified pore water pressure field. The additional cohesion of the root system is calculated based on the root tensile strength and root area ratio in the plant root system parameters, and the additional cohesion of the root system is superimposed on the soil cohesion of the target ecological slope protection to generate the reinforced soil cohesion. Based on the strength reduction method and the time-by-time method, the safety factor of the target ecological slope protection is determined according to the cohesion of the reinforced soil and the effective stress distribution. The safety factors at each time point are arranged in chronological order to generate the time history curve of the safety factors.

8. The method for evaluating the ecological slope protection effect under dynamic water level impact according to claim 7, characterized in that, The time-by-time method based on the strength reduction approach determines the safety factor of the target ecological slope protection according to the cohesion of the reinforced soil and the effective stress distribution, specifically including: Determine the target time and the effective stress distribution under the modified pore water pressure field corresponding to the target time; Obtain the regional geological parameters of the target ecological slope protection, and extract the soil internal friction angle from the regional geological parameters; Gradually reduce the cohesion and internal friction angle of the reinforced soil until the plastic strain region of the seepage stress coupling model is fully penetrated; The reduction factor when the plastic strain region is being penetrated is determined as the safety factor at the target time; Reselect the target time and iterate through all times of the safety factor time history curve to obtain the safety factor corresponding to all times of the safety factor time history curve.

9. The method for evaluating the ecological slope protection effect under dynamic water level impact according to claim 1, characterized in that, The determination of the stability of the target ecological slope protection based on the safety factor time history curve of each sampling node specifically includes: Extract the peak value, valley value, peak occurrence time, and valley occurrence time of the safety factor from the safety factor time history curve; The stability fluctuation range is determined based on the difference between the peak value and the trough value of the safety factor; The stability decay rate is determined based on the time interval between the peak occurrence time and the trough occurrence time. The safety factor at each moment in the safety factor time history curve is compared with a preset safety factor threshold, and the period of time during which the safety factor is lower than the preset safety factor threshold is determined as the target period of time. The stability of the target ecological slope protection is determined based on the stability fluctuation amplitude, the stability decay rate, and the target duration.

10. A system for evaluating the effectiveness of ecological slope protection under dynamic water level impact, characterized in that, It includes a processor and a memory; wherein the memory stores a computer program, the computer program being loaded by the processor and executed as described in any one of claims 1-9, a method for evaluating the ecological slope protection effect under dynamic water level impact.

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