Method for determining non-limiting active earth pressure of complex terrain retaining wall

Abstract

The present application relates to the field of civil engineering and computer-aided design technology, and particularly relates to a method for determining non-limiting active earth pressure of a retaining wall in complex terrain. The method comprises the following steps: obtaining and spatially discretizing original survey data to form a set of parameterized grid points; constructing a reference pressure grid using the set of parameterized grid points; extracting elevation information of each grid element in the reference pressure grid, locally fitting the elevation information to a surface, and calculating the principal curvatures of the terrain surface to form a terrain curvature spectrum; analyzing the curvature distribution of the curvature characteristic region in the terrain curvature spectrum to obtain statistical characteristics of the curvature distribution; and analyzing the soil arching effect according to the statistical characteristics of the curvature distribution to obtain soil arching curvature influence law data. The present application converts complex three-dimensional boundary conditions that are difficult to handle into an accurately quantifiable terrain curvature spectrum, thereby improving the safety and economy of retaining wall design under complex terrain conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of civil engineering and computer-aided design technology, in particular to a method for determining non-limiting active earth pressure of a retaining wall in complex terrain. BACKGROUND

[0002] Traditional earth pressure determination methods are based on a simplified "soil column model", which assumes that the pressure at any point on the wall is determined only by the weight of the vertical soil column above it, completely ignoring the ability of the soil as a friction material to spontaneously form "soil arch" structures that can transfer part of the pressure to other areas, resulting in significant differences between actual earth pressure distribution and theoretical calculations, especially in non-flat terrain conditions. This deviation can lead to safety hazards or resource waste in structural design; existing analysis methods are difficult to effectively handle complex terrain conditions, and most theories are based on flat or simple inclined terrain assumptions. For complex terrain such as stepped, uneven, and complex terrain, it is difficult to accurately predict stress distribution characteristics, especially the stress concentration that occurs at sharp changes in terrain (such as the edge of a step, a trench, etc.) or the stress dispersion effect formed in a depression area, which is severely underestimated, forcing engineers to adopt overly conservative design solutions; engineering practice faces a dilemma in choosing a calculation method. Simplified calculation methods (such as the equivalent slope method) are easy to operate but lack precision, while high-precision finite element analysis requires a large amount of computing resources, specialized software, and extensive experience, making it costly and time-consuming to implement, which small and medium-sized projects cannot afford. The engineering community urgently needs an intermediate approach that is both simple to calculate and reasonably reflects the actual situation.

[0003] In summary, the existing technology has the problem of being unable to efficiently and accurately calculate the non-limiting active earth pressure distribution under complex terrain conditions. SUMMARY

[0004] Therefore, it is necessary to provide a method for determining non-limiting active earth pressure of a retaining wall in complex terrain to solve at least one of the above technical problems.

[0005] To achieve the above purpose, a method for determining non-limiting active earth pressure of a retaining wall in complex terrain includes the following steps:

[0006] Step S1: Obtain and spatially discretize the original survey data to form a set of parameterized grid points; use the set of parameterized grid points to construct a reference pressure grid;

[0007] Step S2: Extract the elevation information of each grid cell in the reference pressure grid, perform local surface fitting on the elevation information, and calculate the principal curvature of the terrain surface to form a terrain curvature spectrum;

[0008] Step S3: analyze the curvature distribution of the curvature characteristic region in the terrain curvature spectrum to obtain curvature distribution statistical features; analyze the soil arching effect according to the curvature distribution statistical features to obtain soil arching curvature influence law data; perform parameter physical mapping analysis on the soil arching curvature influence law data to construct a curvature pressure mapping function; calibrate the soil physical properties in the active state for the curvature pressure mapping function to obtain an active state calibration mapping function; and perform stress redistribution weight conversion on the active state calibration mapping function to obtain a stress redistribution weight set;

[0009] Step S4: determine the non-limiting active state according to the reference pressure grid and the stress redistribution weight set to obtain a non-limiting active reference pressure field; and perform soil pressure distribution correction processing on the non-limiting active reference pressure field by using the stress redistribution weight set to obtain a corrected soil pressure distribution map.

[0010] By high-precision spatial discretization and differential geometry analysis of real complex terrain, the complex three-dimensional boundary conditions that are difficult to handle in traditional methods are innovatively transformed into a terrain curvature spectrum that can be accurately quantified, providing a solid and reliable geometric input for subsequent mechanical analysis. On this basis, the soil arching effect is analyzed based on the curvature spectrum and a nonlinear mapping function is constructed, which cleverly realizes the direct and efficient conversion from "geometric form" to "mechanical response", and for the first time quantifies the mutual enhancement mechanism between wall displacement and soil arching effect through active state calibration, which effectively avoids the complex numerical simulation required by traditional finite element methods. Finally, under real non-limiting displacement working conditions, the mapping relationship is used to finely correct the reference pressure field based on physical conservation, thereby generating a corrected soil pressure distribution map that not only deeply reflects the stress redistribution law of complex terrain, but also accurately considers the behavior of soil under non-limiting conditions. In summary, this method provides a new paradigm for determining the soil pressure of retaining walls under complex terrain conditions, which has high precision, high efficiency and solid physical foundation, and significantly improves the safety and economy of retaining wall design under complex terrain conditions. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a flowchart of the steps of a method for determining non-limiting active soil pressure of a retaining wall under complex terrain. DETAILED DESCRIPTION

[0012] The technical method of the present application will be described below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0013] Further, the accompanying drawings are included to provide a further understanding of the present application, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application. In the drawings:

[0014] It should be understood that, although terms such as "first", "second", and so on can be used herein to describe various elements, the elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the exemplary embodiments, a first element can be referred to as a second element, and similarly a second element can be referred to as a first element. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0015] To achieve the above object, there is provided Figure 1 The present application provides a method for determining non-limiting active earth pressure of a retaining wall in complex terrain, comprising the following steps:

[0016] Step S1: Obtain and spatially discretize the original survey data to form a parameterized grid point set; and construct a reference pressure grid using the parameterized grid point set;

[0017] In the embodiment of the present application, the original point cloud data of the complex terrain behind the retaining wall is obtained by scanning with the unmanned aerial vehicle laser radar, and after denoising and interpolation processing, a high-precision terrain elevation point set is formed. Then, a unified wall-soil interface coordinate system is established with the wall foot as the reference, and the virtual wall is discretized into a two-dimensional calculation grid with a spacing of 0.5 meters. According to the geological survey report, the physical parameters such as the specific gravity of the soil and the static earth pressure coefficient are assigned to each node in the grid to form a parameterized grid point set. Finally, the depth of each node under the irregular terrain is calculated, and an initial pressure value is calculated according to the classical static earth pressure theory. The coordinates and initial pressure values of all nodes are integrated to construct a reference pressure grid for subsequent calculation.

[0018] Step S2: Extract the elevation information of each grid element in the reference pressure grid, perform local surface fitting processing on the elevation information, and calculate the principal curvature of the terrain surface to form a terrain curvature spectrum;

[0019] In the embodiment of the present application, for each unit in the reference pressure grid, the elevation data of nine points including itself and eight adjacent points are extracted to form a local neighborhood elevation matrix. A local quadratic polynomial surface is fitted by applying the least square method to the matrix, so as to convert the discrete elevation points into continuous and differentiable mathematical expressions. Based on the second order coefficients of the surface, the eigenvalues of the shape operator matrix are solved by differential geometry calculation to obtain the maximum and minimum principal curvatures of the point. Finally, the arithmetic mean of the two principal curvatures is selected as the single scalar curvature value of the point, which accurately quantifies the local concave-convex degree of the terrain. The curvature values of all units are integrated into a matrix with the same size as the reference pressure grid, that is, a terrain curvature spectrum is formed.

[0020] Step S3: analyzing the curvature distribution of the curvature characteristic region in the terrain curvature spectrum to obtain curvature distribution statistical characteristics; analyzing the soil arching effect according to the curvature distribution statistical characteristics to obtain soil arching curvature influence law data; performing parameter physical mapping analysis on the soil arching curvature influence law data to construct a curvature pressure mapping function; calibrating the soil physical properties of the curvature pressure mapping function in the active state to obtain an active state calibration mapping function; and converting the stress redistribution weight of the active state calibration mapping function to obtain a stress redistribution weight set;

[0021] In the embodiment of the present application, the terrain curvature spectrum is statistically analyzed, the terrain is divided into basic influence modes such as significant convex and general concave, and the mechanical mechanism of soil arching formation and stress transfer under different modes is analyzed. Based on this analysis, a curvature pressure mapping function with a segmented logistic function as the core is constructed, which directly converts the terrain curvature into a stress redistribution coefficient. Then, in order to reflect the enhancement effect of wall displacement on the soil arching effect, the displacement-induced soil rearrangement is analyzed to calculate the “active state strengthening factor” related to displacement, and the parameters of the mapping function are calibrated by using the active state strengthening factor to generate an active state calibration mapping function. Finally, for a specific design displacement working condition, the stress redistribution coefficient values of each point on the wall surface are calculated by using the calibration function, and after boundary effect correction, a stress redistribution weight set is formed.

[0022] Step S4: determining the non-limit active state according to the reference pressure grid and the stress redistribution weight set to obtain a non-limit active reference pressure field; and performing soil pressure distribution correction processing on the non-limit active reference pressure field by using the stress redistribution weight set to obtain a corrected soil pressure distribution diagram;

[0023] In the embodiment of the present application, the actual displacement of each grid unit on the back of the retaining wall is calculated according to the designed displacement of the retaining wall (such as rotating 6 mm around the wall foot), and compared with the theoretical displacement required to reach the limit active state at this depth, to obtain a relative displacement ratio distribution. According to the ratio, the non-limit active pressure coefficient corresponding to each unit is calculated using the hyperbolic model, and then a non-limit active reference pressure field considering the displacement of the wall but not the terrain effect is generated. Subsequently, the reference pressure field is multiplied by the stress redistribution weight set obtained in step S3 on a unit-by-unit basis to obtain a preliminary corrected pressure field. Finally, through a global pressure balance check, it is ensured that the total force of the soil body behind the wall before and after correction remains unchanged, the pressure field is finally adjusted, and the total force and action point of the wall surface are calculated. These accurate pressure distribution data are packaged together with the macroscopic characteristic values to generate the final corrected soil pressure distribution map.

[0024] Preferably, step S1 comprises:

[0025] Obtain the original survey data of the terrain behind the retaining wall, and perform terrain data preprocessing to obtain a terrain elevation point set;

[0026] Determine the geometric size of the retaining wall, and establish a wall-soil interface coordinate system in combination with the terrain elevation point set;

[0027] Generate a spatial discrete grid according to the wall-soil interface coordinate system;

[0028] Obtain the physical parameters of the soil body, and assign the soil body parameters to the spatial discrete grid to obtain a parameterized grid point set;

[0029] Calculate the reference static soil pressure for the parameterized grid point set to obtain a node pressure value set;

[0030] Integrate the node pressure value set and the spatial discrete grid to obtain a reference pressure grid.

[0031] In an embodiment, the terrain within a range of 100 meters long and 50 meters wide behind the retaining wall is scanned by a drone carrying a laser radar (LiDAR) to obtain original point cloud data. The computer performs preprocessing on the point cloud data, first eliminates isolated noise points with a flight height lower than the average elevation of the ground, and then encrypts the data sparse area using the Kriging interpolation method, finally generates a terrain elevation point set with an average interval of 1 meter, containing (x, y, z) three-dimensional coordinate information.

[0032] The retaining wall is set as a gravity retaining wall, the wall height H = 10 meters, the wall length L = 100 meters, and the angle β between the wall back and the vertical direction is 5 degrees. The center point of the wall foot line is taken as the coordinate origin O (0, 0, 0), and the coordinate system is defined: the X axis is perpendicular to the wall surface and points to the soil body behind the wall, the Y axis is along the wall foot line, and the Z axis is vertically upward. This coordinate system serves as a unified reference for all subsequent calculations.

[0033] The virtual inclined plane where the retaining wall back is located is divided along the Y axis (wall length direction) and the Z axis (vertical direction) at a constant interval of 0.5 meters to generate a 200x20 two-dimensional rectangular grid. The implementation logic of this operation is to discretize the continuous wall soil acting surface into a limited number of calculation units, laying the foundation for subsequent point-by-point calculation of pressure. This grid is a spatial discrete grid.

[0034] According to the geological survey report, the physical parameters of the backfill soil are obtained: the soil bulk density γ = 19 kN / m³, the static soil pressure coefficient K_0 = 0.5, and the internal friction angle φ = 30 degrees. The computer assigns these homogeneous soil parameters as an attribute set to each grid node in the spatial discrete grid, forming a data set that not only contains geometric coordinates but also carries physical and mechanical attributes, i.e., a parameterized grid point set.

[0035] For each node in the parameterized grid point set, the classical static soil pressure formula is applied:

[0036] P_0 = K_0 × γ × z;

[0037] The calculation is performed. Among them, P_0 is the initial static soil pressure value of the node, K_0 is the static soil pressure coefficient, γ is the soil bulk density, and z is the vertical distance from the grid node to the irregular terrain surface directly above it. By traversing all nodes, a pressure value array corresponding to each grid node is generated, i.e., a node pressure value set. The logic of this operation is to construct an idealized pressure field that does not consider the soil arching effect as the starting point for subsequent correction.

[0038] Each pressure value in the node pressure value set is bound to its position in the spatial discrete grid in the data structure. Specifically, a two-dimensional matrix is created, with the row and column indices corresponding to the Y and Z indices of the grid, and each element of the matrix storing a composite data body containing the center point (y, z) coordinates and corresponding P_0 value of the unit. This data structure that integrates spatial position and initial pressure information is the baseline pressure grid, which is the direct data basis for subsequent terrain curvature calculation and stress correction steps.

[0039] Preferably, step S2 comprises:

[0040] The baseline pressure grid is analyzed to extract neighborhood elevation data, obtaining a neighborhood elevation matrix;

[0041] performing local terrain surface fitting on the neighborhood elevation matrix to obtain a local surface coefficient set;

[0042] performing principal curvature scalarization operation on the local surface coefficient set to obtain a point curvature value;

[0043] performing terrain curvature spectrum matrix synthesis on the point curvature value to obtain a terrain curvature spectrum.

[0044] In an embodiment, each grid cell in the reference pressure grid is traversed. For any cell, the system extracts the elevation information of itself and its eight closest neighbors (collectively forming a 3x3 analysis window) on the terrain surface. The implementation logic of this operation is to reduce the global terrain analysis to an accurate description of the local geometric configuration of each calculation point. The nine elevation data extracted are organized into a 3x3 matrix, which is the neighborhood elevation matrix.

[0045] For each neighborhood elevation matrix, the least square method is applied to fit the nine elevation points contained therein into a quadratic polynomial surface:

[0046] Z(x,y) = ax +by +cxy+dx+ey+f;

[0047] where Z(x,y) is the elevation on the fitted surface, x and y are local plane coordinates, and a, b, c, d, e, and f are the surface coefficients to be solved. By solving this fitting problem, a set of six surface coefficients {a, b, c, d, e, f} is obtained, which is the local surface coefficient set. This step converts the discrete elevation point set into a continuous and differentiable local mathematical model, providing a mathematical basis for subsequent curvature calculation through differential geometry methods.

[0048] Using the second-order term coefficients a and b in the local surface coefficient set obtained in the previous step, the second-order partial derivatives of the fitted surface Z(x,y) are calculated, and the average curvature H of the center point position of the cell is calculated according to the principles of differential geometry. The average curvature H is the arithmetic mean of the two principal curvatures of the point, and its sign directly indicates the convexity (positive value) or concavity (negative value) of the terrain, and its absolute value quantifies the degree of concave-convex. This single value is the point curvature value, which completes the conversion from "terrain geometric configuration" to "quantifiable mechanical influence factor" and accurately expresses the geometric prerequisite for the occurrence of soil arching effect.

[0049] A new 2D matrix with the same size as the reference pressure grid (e.g. 200x20) is created. Then, the point curvature value H calculated in the last step for each grid cell is filled into the corresponding cell in the new matrix. After all the cells are processed, the final data matrix is the terrain curvature spectrum. This step integrates the discrete curvature values calculated point by point into a global data field, which intuitively shows the concave-convex distribution of the entire terrain behind the wall, and provides complete input data for the next step to establish the mapping relationship between curvature and stress redistribution.

[0050] Especially important is that the principal curvature scalarization operation on the local surface coefficient set is specifically:

[0051] Extracting a set of differential geometry basic parameters from the local surface coefficient set;

[0052] Constructing a curvature tensor matrix according to the set of differential geometry basic parameters;

[0053] Performing principal curvature eigenvalue calculation on the curvature tensor matrix to obtain a principal curvature data pair;

[0054] Performing curvature scalar selection and physical meaning mapping on the principal curvature data pair to obtain a point curvature value;

[0055] In an embodiment, from the local surface coefficient set {a, b, c, d, e, f}, parameters for constructing a Gaussian second fundamental form matrix are extracted. Specifically, the parameter L is equal to 2a, the parameter M is equal to c, and the parameter N is equal to 2b. At the same time, parameters for constructing a Gaussian first fundamental form matrix, i.e. first-order partial derivatives Z_x=d and Z_y=e, are extracted from the coefficient set. The implementation logic of this operation is to convert the algebraic coefficients of polynomial fitting into standard parameters for describing the local bending properties of the surface in differential geometry.

[0056] Using the set of differential geometry basic parameters extracted in the last step, a 2x2 shape operator (or Weingarten mapping) matrix W is constructed. This matrix W integrates the first and second fundamental forms of the surface, and its elements are functions of parameters L, M, N, and Z_x, Z_y. This step is a key step in the present application to convert geometric information into linear algebra analysis, and the constructed matrix W completely encodes the bending information of the point in all directions.

[0057] An eigenvalue solving operation is performed on each of the curvature tensor matrices W. This linear algebra operation results in two real solutions, k_1 and k_2. These two eigenvalues correspond to the maximum and minimum curvatures of the terrain surface at the point, respectively, i.e. the two principal curvatures. These two values constitute a principal curvature data pair {k_1, k_2}. The core logic of this step lies in that by solving the eigenvalues, the complex surface curvature pattern is decomposed into the most basic and most significant bending measures in two mutually orthogonal directions.

[0058] An arithmetic average is taken of the principal curvature data pair {k_1, k_2} to calculate the average curvature H = (k_1 + k_2) / 2. The average curvature H is selected as the final point curvature value, and the implementation logic thereof lies in that the average curvature H is a single scalar that can comprehensively reflect the overall concave-convex trend of the point. If k_1 and k_2 are of the same sign, H reflects whether the point is "bowl-shaped" concave (H < 0) or "dome-shaped" convex (H > 0), which directly corresponds to the unloading or focusing effect of the soil arch. If k_1 and k_2 are of different signs (saddle point), the positive or negative of H reveals which of the principal directions the bending of the point is more severe, thereby indicating the dominant direction of stress transfer. Through this scalarization operation, the complex three-dimensional geometric problem is simplified into a single parameter that has a direct physical connection with the redistribution of earth pressure, greatly simplifying the subsequent mechanical mapping model.

[0059] Preferably, the soil arch effect analysis according to the curvature distribution statistical characteristics in step S3 comprises:

[0060] determining a curvature influence basic mode according to the curvature distribution statistical characteristics to obtain the curvature influence basic mode;

[0061] performing soil arch formation analysis on the curvature influence basic mode to obtain a soil arch formation condition table;

[0062] constructing a pressure transfer schematic diagram according to the soil arch formation condition table;

[0063] determining a curvature threshold value according to the pressure transfer schematic diagram to obtain a curvature threshold value quick reference table;

[0064] determining an influence range and intensity according to the curvature threshold value quick reference table and the pressure transfer schematic diagram to obtain soil arch curvature influence law data.

[0065] In an embodiment, a statistical analysis is performed on the entire terrain curvature spectrum to generate a frequency distribution histogram of the curvature value (H). According to the distribution characteristics of the histogram, the terrain is divided into five basic influence modes:

[0066] H > 0.1, defined as a "significant convex mode", corresponding to a highly concentrated stress area.

[0067] 0.01 < H ≤ 0.1, defined as "general convex mode", corresponding to a slightly stress-concentrated area.

[0068] -0.01 ≤ H ≤ 0.01, defined as "quasi-flat mode", corresponding to a soil arching effect negligible area.

[0069] -0.1 < H < -0.01, defined as "general concave mode", corresponding to a slightly stress-unloading area of soil arching.

[0070] H < -0.1, defined as "significant concave mode", corresponding to a significantly stress-unloading area of soil arching.

[0071] Based on the preset geotechnical mechanics knowledge base, the mechanical behavior of each curvature influence basic mode is analyzed:

[0072] In the "significant concave mode", the particles form a stable three-dimensional pressure arch through interlocking and friction, which transmits the overlying load to the arch foot (the area with smaller curvature or positive curvature).

[0073] In the "significant convex mode", the pressure arch cannot be formed, but it becomes the arch foot of the surrounding pressure arch, bearing additional pressure transferred from the concave area, forming stress focusing.

[0074] In the "quasi-flat mode", it does not have the geometric conditions to form an effective soil arch.

[0075] The above analysis results are solidified into a data table, namely the soil arching formation condition table, which contains the mapping relationship between the curvature mode and the corresponding mechanical mechanism (such as "stable unloading arch formation", "stress focusing").

[0076] The pressure transfer schematic diagram is constructed in the form of data structure, rather than generating graphics. For each unit in the terrain curvature spectrum, according to its belonging to the curvature influence basic mode, a pressure transfer tendency identifier is assigned. For example, the unit with "significant concave mode" is assigned with "pressure source" identifier, and the unit with "significant convex mode" is assigned with "pressure sink" identifier. This operation simulates the transmission direction of stress flow at the data level, and clearly defines the source and sink of stress redistribution.

[0077] Based on the built-in empirical database or theoretical model, a series of key curvature thresholds are determined. For example:

[0078] The unloading start threshold H_unload_start = -0.015.

[0079] The unloading saturation threshold H_unload_max = -0.2.

[0080] The focus start threshold H_focus_start = 0.015.

[0081] Focus saturation threshold H_focus_max = 0.25.

[0082] These thresholds are stored in a lookup table in the form of key-value pairs for subsequent quick queries.

[0083] Based on the above information, the final soil arch curvature influence law data is generated. This data is a set of quantitative rules, for example:

[0084] Rule 1: For elements with curvature H in the interval (-0.2, -0.015), the stress unloading strength increases linearly with the increase of the absolute value of H, and the maximum unloading ratio is 50%.

[0085] Rule 2: For elements with curvature H in the interval (0.015, 0.25), the stress focusing strength increases nonlinearly with the increase of H value, and the maximum increase is 40%.

[0086] Rule 3: For elements with curvature H less than -0.2, the unloading ratio is constant at 50%; for elements with curvature H greater than 0.25, the increase is constant at 40%.

[0087] This set of data precisely defines the quantitative relationship from curvature to stress correction strength, which is the core basis for constructing the next mapping function.

[0088] Preferably, the parameter physical mapping analysis of the soil arch curvature influence law data in step S3 comprises:

[0089] determining the mathematical expression of the mapping function according to the soil arch curvature influence law data;

[0090] performing parameter physical significance analysis on the mathematical expression of the mapping function to obtain a parameter physical meaning table;

[0091] determining an initial value set of mapping parameters according to the parameter physical meaning table and the curvature distribution statistical characteristics;

[0092] constructing the mapping function according to the mathematical expression of the mapping function and the initial value set of the mapping parameters to obtain the curvature-pressure mapping function.

[0093] In an embodiment, according to the non-linear, saturation interval characteristic revealed in the soil arching curvature influence law data, a piecewise modified Logistic Function is determined as the mathematical expression of the mapping function μ(H). Wherein, μ is the stress redistribution coefficient, and H is the terrain curvature. The function adopts different parameter sets in H>0 (convex area) and H<0 (concave area) to simulate the stress concentration and unloading two physical mechanisms respectively. The implementation logic of this operation is that the Logistic Function naturally has the "S" shaped curve characteristic from initial gentle growth (or reduction) to rapid change and finally saturation, which is highly consistent with the physical process of soil arching effect from nothing to full development.

[0094] The selected Logistic Function expression is parameterized and analyzed, and the following parameter physical meaning table is established:

[0095] Parameter μ_max: defined as the stress concentration upper saturation value, the physical meaning is the maximum stress amplification coefficient that the convex terrain can achieve.

[0096] Parameter μ_min: defined as the stress unloading lower saturation value, the physical meaning is the maximum stress reduction coefficient that the concave terrain can achieve through soil arching effect.

[0097] Parameter k_f: defined as the focusing sensitivity coefficient, the physical meaning is the rate at which the stress amplification effect increases with the curvature in the stress concentration stage.

[0098] Parameter k_u: defined as the unloading sensitivity coefficient, the physical meaning is the rate at which the stress reduction effect increases with the absolute value of the curvature in the stress unloading stage.

[0099] Parameter H_f0: defined as the focusing conversion center point, the physical meaning is the terrain curvature value corresponding to half the effect of μ_max.

[0100] Parameter H_u0: defined as the unloading conversion center point, the physical meaning is the terrain curvature value corresponding to half the effect of μ_min.

[0101] The implementation logic is to one-to-one correspond the pure mathematical function parameters with the clear geotechnical mechanics concepts, so that the function adjustment is no longer a blind numerical fitting, but a clear physical oriented calibration process.

[0102] According to the soil arching curvature influence law data generated in the previous step, the parameters are assigned to form the initial value set of the mapping parameters. For example:

[0103] If the "maximum increase is 40%" in the law data, then μ_max is assigned a value of 1.4.

[0104] If the "maximum unloading ratio is 50%", then μ_min is assigned a value of 0.5.

[0105] If the unloading effect occurs between the curvature -0.015 to -0.2, the unloading transition center point H_u0 is assigned as:

[0106] (-0.015-0.2) / 2=-0.1075;

[0107] At the same time, the unloading sensitivity coefficient k_u is calculated according to the width of the interval.

[0108] The assignment process of the focusing parameter is similar. This operation converts the semi-quantitative analysis conclusion in the previous step into a specific numerical value that can be substituted into the function calculation.

[0109] Substitute all the values in the initial value set of the mapping parameter into the piecewise logistic function mathematical expression determined in the first step. After this process is completed, a complete, calibrated function that can receive any terrain curvature value H as input and accurately output the corresponding stress redistribution coefficient μ is generated. This function is the curvature pressure mapping function. It materializes the core idea of the present application of directly deriving mechanical response from geometric form, and is the key bridge connecting the terrain curvature spectrum and the final stress correction.

[0110] Preferably, the active state soil physical property calibration of the curvature pressure mapping function in step S3 comprises:

[0111] According to the parameterized grid point set, the active soil pressure state feature analysis is performed to obtain active state development data;

[0112] The soil parameter characteristic set is extracted from the original survey data, and the active state development mode analysis is performed in combination with the active state development data to obtain active state soil arch evolution law data;

[0113] The active state soil arch evolution law data is subjected to internal friction angle correction coefficient determination to form an internal friction angle correction parameter group;

[0114] According to the active state soil arch evolution law data and the internal friction angle correction parameter group, an active state reinforcement factor set is calculated;

[0115] According to the active state reinforcement factor set, the wall-soil interface friction influence is evaluated to obtain an interface correction coefficient pair;

[0116] Based on the curvature pressure mapping function, the internal friction angle correction parameter group, the active state reinforcement factor set and the interface correction coefficient pair, an active state calibration mapping function is generated.

[0117] In an embodiment, the theoretical displacement value required for the wall to reach the limit active state is calculated based on the physical parameters of the soil in the parameterized grid point set, such as the internal friction angle φ. For example, for a retaining wall with a height H = 10 meters, the displacement value required to reach the limit active state is calculated as:

[0118] Δ_a = 0.001 × H = 10 mm;

[0119] This displacement value, together with the static state (displacement of 0), defines the complete development interval of the soil from the static to the active state, which is the active state development data.

[0120] As the wall displaces outward, the soil relaxes and reorganizes, causing the soil arching effect to change. The specific rules are:

[0121] 1. In the concave area, the displacement enhances the interlocking effect between soil particles, making the soil arch more stable, and the unloading effect is enhanced.

[0122] 2. In the convex area, the displacement causes the soil in this area to be further "squeezed", and the stress concentration effect is intensified.

[0123] This rule is quantified as: for every 25% of the limit displacement Δ_a reached by the wall displacement, the unloading effect in the concave area is enhanced by 5%, and the focusing effect in the convex area is enhanced by 3%. This quantified relationship is the active state soil arch evolution rule data.

[0124] According to the active state soil arch evolution rule data, the correlation between soil parameters and soil arch evolution is established. Specifically, the enhancement of the unloading effect is equivalent to the increase of the internal friction angle φ of the soil in the concave area, and the intensification of the focusing effect is equivalent to the decrease of the internal friction angle φ of the soil in the convex area. Through back calculation, a correction coefficient function C_φ(H) is determined, which inputs the curvature H and outputs a multiplication coefficient for adjusting the internal friction angle φ. For example, in the significantly concave area (H = -0.2), C_φ = -1.1; in the significantly convex area (H = 0.25), C_φ = 0.95. This set of correction coefficient functions related to curvature is the internal friction angle correction parameter set.

[0125] An active state reinforcement factor α(H, δ_r) is defined, where H is the curvature and δ_r is the ratio of the current displacement of the wall to the limit active displacement Δ_a (relative displacement ratio). Based on the active state soil arch evolution rule data, it is set that when δ_r = 1, in the significantly concave area α = -1.2 (indicating that the unloading effect is enhanced by 20%), and in the significantly convex area α = 1.15 (indicating that the focusing effect is enhanced by 15%). This reinforcement factor set α(H, δ_r) accurately describes the degree of reinforcement of the soil arch effect relative to the static state at different displacement levels and different terrain positions.

[0126] The influence of wall displacement on the wall-soil interface friction angle δ is evaluated. When the wall displaces downward and outward, the wall-soil interface friction angle δ is fully mobilized. This effect is quantified as a pair of correction factors {C_δ_concave, C_δ_convex}. In the concave region, the wall-soil friction is reduced due to the unloading of the soil arch, so C_δ_concave = 0.9. In the convex region, the wall-soil friction is increased due to the pressure concentration, so C_δ_convex = 1.1.

[0127] The original curvature pressure mapping function μ(H) is modified to generate the active state calibrated mapping function μ_calibrated(H, δ_r). The construction logic is that the parameters of μ(H) (such as μ_max, μ_min) are multiplied by the active state intensification factor α(H, δ_r), and the soil parameters involved in the calculation process (such as φ) are replaced by the adjusted values of the internal friction angle correction parameter group C_φ(H) and the interface correction factor pair. The final μ_calibrated(H, δ_r) is a more accurate stress redistribution coefficient mapping function that not only considers the terrain curvature but also dynamically reflects the influence of wall displacement.

[0128] Preferably, the set of active state intensification factors is calculated according to the active state soil arch evolution law data and the internal friction angle correction parameter group, and includes:

[0129] According to the active state soil arch evolution law data, the displacement-induced soil rearrangement analysis is performed to obtain the displacement soil structure change characteristics;

[0130] According to the displacement soil structure change characteristics, the active state-soil arch coupling processing is performed to obtain coupling data;

[0131] According to the coupling data and the internal friction angle correction parameter group, the convex region intensification factor table is calculated to obtain the convex region intensification factor table;

[0132] According to the coupling data and the internal friction angle correction parameter group, the concave region intensification factor table is calculated to obtain the concave region intensification factor table;

[0133] The convex region intensification factor table and the concave region intensification factor table are integrated and mapped to form the set of active state intensification factors.

[0134] In an embodiment, based on the active state soil arch evolution law data, the following analysis is performed:

[0135] In the concave region (H < 0), the wall displacement causes the soil to relax, and the particles roll and slide under the action of gravity to more stable positions, making the soil skeleton structure more compact and the porosity lower. This phenomenon is defined as "positive rearrangement", and its characteristic is that the soil arch locking effect is enhanced due to the structure densification.

[0136] In convex region (H>0), wall displacement causes the soil in this region to be passively compressed, and when the stress exceeds its bearing capacity, a through shear slip surface is formed inside the soil, and the stress is redistributed along the slip surface and "converges" towards the wall. This phenomenon is defined as "shear convergence", which is characterized by the stress concentration effect intensified by structural failure.

[0137] The above analysis results are the displacement soil structure change characteristics.

[0138] The displacement soil structure change characteristics are quantified. A coupling strength function γ_c(H, δ_r) is defined, where H is the curvature and δ_r is the relative displacement ratio. This function quantifies the contribution of displacement to the soil arching effect:

[0139] For the "positive rearrangement" of the concave region, the coupling strength increases linearly with δ_r:

[0140] γ_c = 1 + 0.2 × δ_r.

[0141] For the "shear convergence" of the convex region, the coupling strength increases nonlinearly with δ_r:

[0142] γ_c = 1 + 0.15 × (δ_r) .

[0143] This function relationship is the coupling data. The implementation logic of this step is to provide a precise, quantified description of the influence of displacement, an external factor, on the soil arching effect, an intrinsic effect, as the displacement develops.

[0144] The active state reinforcement factor α_convex is calculated for the convex region (H>0). The calculation logic is that the basic reinforcement effect is determined by the coupling data γ_c, and the strength change of the soil itself (reflected by the internal friction angle correction parameter group C_φ(H)) modulates this reinforcement effect. The specific calculation is:

[0145] α_convex = γ_c / C_φ(H);

[0146] Where C_φ(H)<1 indicates that the equivalent strength of the convex region decreases, and dividing by a number less than 1 will further amplify the reinforcement factor α_convex, which is consistent with the physical fact that "shear convergence" intensifies. After calculation, a two-dimensional lookup table, the convex region reinforcement factor table, is generated, with curvature H and relative displacement ratio δ_r as indices and α_convex as values.

[0147] Similarly, the active state reinforcement factor α_concave is calculated for the concave region (H<0). The calculation logic is:

[0148] α_concave = γ_c × C_φ(H);

[0149] where C _ φ(H) > 1 indicates that the concave region soil strength is increased, and multiplying by a number greater than 1 will result in the amplification of the strengthening factor α_concave, which is consistent with the physical fact of "positive rearrangement" to make the soil arch more stable. After calculation, a concave region strengthening factor table is generated, which has the same structure as the convex region strengthening factor table.

[0150] A piecewise function α(H, δ_r) is created, which serves as the final active state strengthening factor set. Its internal logic is as follows:

[0151] 1. Check the sign of the input curvature H.

[0152] 2. If H > 0, look up or interpolate in the convex region strengthening factor table to obtain α_convex as the function return value.

[0153] 3. If H < 0, look up or interpolate in the concave region strengthening factor table to obtain α_concave as the function return value.

[0154] 4. If H is approximately equal to 0, the return value is always 1.0, indicating that the quasi-plane region is not affected by displacement strengthening.

[0155] The final function or its equivalent data structure can provide an accurate soil arch effect strengthening factor for any terrain point under any displacement state.

[0156] Preferably, the stress redistribution weight conversion of the active state calibration mapping function in step S3 comprises:

[0157] According to the active state calibration mapping function and the terrain curvature spectrum, an initial redistribution coefficient field is calculated;

[0158] The initial redistribution coefficient field is modified for boundary effect, to obtain a modified redistribution coefficient field;

[0159] The modified redistribution coefficient field is integrated for stress redistribution weight set, to obtain a stress redistribution weight set.

[0160] In an embodiment, first, a target non-limit state is set, for example, a state corresponding to the wall top displacement reaching 50% of the limit active displacement, i.e., the relative displacement ratio δ_r = 0.5. Subsequently, each cell in the terrain curvature spectrum is traversed, and the curvature value H of the cell is read. The curvature H and the set relative displacement ratio δ_r = 0.5 are taken as inputs together and substituted into the active state calibration mapping function μ_calibrated(H, δ_r) for calculation. This operation is performed for each cell to obtain a corresponding stress redistribution coefficient value μ. All these μ values constitute a two-dimensional matrix with the same size as the terrain curvature spectrum, which is the initial redistribution coefficient field.

[0161] The implementation logic of this step is that the soil arching effect cannot fully develop near the free boundary of the soil body (such as the ground surface and the ends of the wall), and needs to be corrected. Identify the elements in the initial redistribution coefficient field located in the boundary influence zone. This influence zone is defined as the area within 2 meters of the ground surface and within 3 meters of the lateral boundaries at both ends of the wall. For any element located in the influence zone, the corrected coefficient μ_corrected is calculated as follows:

[0162] μ_corrected=1+(μ-1)×f_b;

[0163] Where μ is the initial coefficient value of the element, and f_b is the boundary influence factor, which increases linearly from 0 at the boundary to 1 at the edge of the influence zone. This operation forces the coefficient at the boundary to be pulled back to 1.0 (no soil arching effect), and smoothly transitions to the fully effective zone, avoiding stress discontinuity. The corrected matrix is the corrected redistribution coefficient field.

[0164] This step is the process of solidifying the calculation results into standard data products. The corrected redistribution coefficient field obtained in the previous step (a pure numerical matrix) is integrated with the metadata describing its properties. The metadata includes: grid size (200x20), relative displacement ratio (δ_r=0.5) on which the calculation is based, and coordinate system information. This complete data package containing the numerical matrix and metadata is finally defined and stored as a stress redistribution weight set. The implementation logic of this operation is to encapsulate the calculation results into a self-explanatory, standardized data object that can be directly called by subsequent steps, ensuring the accuracy and consistency of data transmission throughout the entire method flow.

[0165] Preferably, the non-limiting active state determination in step S4 according to the reference pressure grid and the stress redistribution weight set comprises:

[0166] Data format unification and preprocessing are performed on the reference pressure grid and the stress redistribution weight set to obtain a registration data pair;

[0167] Obtain the design displacement data of the retaining wall, and analyze the displacement characteristics of the wall in combination with the registration data pair to obtain a wall displacement distribution curve;

[0168] Calculate the relative displacement ratio according to the wall displacement distribution curve to obtain a relative displacement ratio distribution map;

[0169] Determine a non-limiting coefficient distribution matrix according to the relative displacement ratio distribution map;

[0170] Perform complex terrain soil pressure correction using the non-limiting coefficient distribution matrix to obtain a terrain correction pressure coefficient field;

[0171] The non-limiting active earth pressure conversion and synthesis are performed on the terrain correction pressure coefficient field and the static earth pressure value in the registration data pair to obtain a non-limiting active reference pressure field.

[0172] In an embodiment, it is checked whether the grid size and the coordinate system of the calibration reference pressure grid and the stress redistribution weight set are consistent. After confirming that both are 200x20 grids and use the same coordinate system, the data of both are matched one by one in the memory according to the grid cell index. For each cell, a data structure containing its static earth pressure value P_0 and stress redistribution weight μ is created. The set of all these data structures is the registration data pair.

[0173] The maximum allowable horizontal displacement of the wall top defined in the retaining wall design specification is 6mm. The wall displacement mode is set as rotation around the wall foot. Based on this mode, the horizontal displacement of any height z on the wall back is calculated as:

[0174] Δ(z)=(z / H)×6mm;

[0175] where H is the wall height of 10m. This linear function relationship is the wall displacement distribution curve.

[0176] For each grid cell on the wall back, the theoretical displacement Δ_a(z) required to reach the limit active state is calculated. This theoretical displacement value is related to the depth, for example, Δ_a(z)=0.001×z. Then, the ratio of the actual displacement Δ(z) of each cell to the theoretically required displacement Δ_a(z) is calculated to obtain the relative displacement ratio of the cell:

[0177] δ_r(z)=Δ(z) / Δ_a(z);

[0178] The δ_r(z) values of all cells form a matrix with the same grid size as the relative displacement ratio distribution map. The implementation logic of this step is to convert the macroscopic wall displacement into a microscopic measure of the "activation" degree of each point on the wall back soil.

[0179] Based on the earth pressure theory, a functional relationship between the non-limiting earth pressure coefficient K and the relative displacement ratio δ_r is established, for example, a hyperbolic model is adopted:

[0180] K=K_0-(K_0-K_a)×δ_r / (A+B×δ_r);

[0181] where K_0 is the static earth pressure coefficient, K_a is the active earth pressure coefficient, and A and B are test constants related to soil properties. The δ_r(z) value of each cell is substituted into this function to calculate the non-limiting earth pressure coefficient K of the cell by traversing the relative displacement ratio distribution map. The matrix composed of all K values is the non-limiting coefficient distribution matrix.

[0182] Traverse each cell in the non-limiting coefficient distribution matrix, read its non-limiting earth pressure coefficient K. Meanwhile, read the unit's corresponding soil bulk density γ and depth z from the registration data pair. Through the formula:

[0183] P_non-limit=K×γ×z;

[0184] The non-limiting active earth pressure value of the unit is calculated when considering the wall displacement but not considering the terrain soil arching effect. The two-dimensional data matrix composed of all these P_non-limit values is the non-limiting active reference pressure field. This field provides accurate input that meets the non-limiting working condition for the next step of terrain effect correction.

[0185] Preferably, the soil pressure distribution correction processing of the non-limiting active reference pressure field by the stress redistribution weight set in step S4 includes:

[0186] According to the non-limiting active reference pressure field and the stress redistribution weight set, the soil pressure distribution correction calculation is performed to obtain the original correction pressure field;

[0187] According to the original correction pressure field and the non-limiting active reference pressure field, the pressure balance verification and adjustment are performed to obtain the balanced correction pressure field;

[0188] The wall surface force and action point calculation is performed on the balanced correction pressure field to obtain the wall surface pressure characteristic value;

[0189] The modified soil pressure distribution map generation is performed on the balanced correction pressure field and the wall surface pressure characteristic value to obtain the modified soil pressure distribution map.

[0190] In an embodiment, the non-limiting active reference pressure field (a 200x20 matrix with elements P_non-limit) and the stress redistribution weight set (a matrix of the same size with elements μ) are subjected to element-by-element multiplication. For each grid cell, its corrected pressure value is:

[0191] P_raw=P_non-limit×μ;

[0192] After this calculation traverses all cells, a new 200x20 pressure matrix is generated, which is the original correction pressure field. The implementation logic of this step is to directly apply the amplification or reduction effect of the soil arching effect on the pressure obtained through geometric analysis to the reference pressure in the non-limiting state.

[0193] The soil arching effect only redistributes the pressure, but does not change the total weight acting on the soil wedge behind the wall. First, the total force F_base is calculated by integrating all the cell pressure values of the non-limiting active base pressure field. Then, the total force F_raw is calculated by integrating all the cell pressure values of the original modified pressure field. A global balancing factor is calculated:

[0194] λ = F_base / F_raw;

[0195] Finally, each pressure value P_raw in the original modified pressure field is multiplied by the balancing factor λ to obtain the final:

[0196] P_balanced = P_raw x λ;

[0197] This operation ensures that the total earth pressure after modification remains constant before modification, accurately simulating the "transfer" of stress rather than "increase or decrease". The modified pressure matrix is the balanced modified pressure field.

[0198] The balanced modified pressure field is integrated. First, the total force F_total acting on the entire wall surface is obtained by summing the pressure values P_balanced of all cells multiplied by their corresponding cell areas (0.5 meters x 0.5 meters). Second, the moment of force of each cell about its wall foot (z = 0) is calculated (P_balanced x cell area x cell center height z), and then the moments of all cells are summed to obtain the total moment M_total. The height z_resultant of the point of application of the resultant force is calculated by M_total / F_total. These two values {F_total, z_resultant} are combined into a data structure, which is the wall pressure characteristic value, used for overall stability check of the retaining wall.

[0199] A final data file is created. This file contains two parts: the first part is the complete balanced modified pressure field (a 200 x 20 matrix containing the accurate pressure value of each point), and the second part is the wall pressure characteristic value {F_total, z_resultant}. This data set, which integrates detailed distribution and key macroscopic indicators, is the modified earth pressure distribution diagram. It can be directly used to generate visual cloud charts, or as load input data to import into structural analysis programs for fine design and safety review of retaining walls.

[0200] Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, the scope of the invention being defined by the appended claims rather than the above description, so as to encompass all variations falling within the meaning and scope of the equivalent elements of the application file.

[0201] The foregoing is considered as illustrative only of the principles of the application. Numerous modifications and changes will readily occur to those skilled in the art, and it is intended to embrace all such modifications and changes that fall within the scope of the application. Accordingly, the application is not to be restricted in scope to the specific embodiments disclosed herein but is to be accorded the full scope that the principles and novel features request appropriately granted.

Claims

1. A method for determining non-limiting active earth pressure of a complex terrain retaining wall, characterized by, The method comprises the following steps: Step S1: obtaining and spatially discretizing the original survey data to form a parameterized grid point set; constructing a reference pressure grid using the parameterized grid point set; Step S2 comprises: analyzing the reference pressure grid to extract neighborhood elevation data to obtain a neighborhood elevation matrix; performing local terrain surface fitting on the neighborhood elevation matrix to obtain a local surface coefficient set; performing principal curvature scalarization calculation on the local surface coefficient set, specifically: extracting a set of differential geometry basic parameters from the local surface coefficient set; constructing a curvature tensor matrix according to the set of differential geometry basic parameters; performing principal curvature eigenvalue calculation on the curvature tensor matrix to obtain a pair of principal curvature data; performing curvature scalar selection and physical meaning mapping on the pair of principal curvature data to obtain a point curvature value; performing terrain curvature spectrum matrix synthesis on the point curvature value to obtain a terrain curvature spectrum; Step S3: analyzing the curvature distribution of the curvature characteristic region in the terrain curvature spectrum to obtain curvature distribution statistical characteristics; analyzing the soil arching effect according to the curvature distribution statistical characteristics to obtain soil arching curvature influence law data; performing parameter physical mapping analysis on the soil arching curvature influence law data, including: determining a piecewise logistic mapping function mathematical expression according to the soil arching curvature influence law data; performing parameter physical meaning analysis on the mapping function mathematical expression to obtain a parameter physical meaning table; determining a set of initial mapping parameters according to the parameter physical meaning table and the curvature distribution statistical characteristics; constructing a mapping function according to the mapping function mathematical expression and the set of initial mapping parameters to obtain a curvature pressure mapping function; performing active state soil physical property calibration on the curvature pressure mapping function, including: performing active soil pressure state characteristic analysis according to the parameterized grid point set to obtain active state development data; extracting a set of soil parameter characteristics from the original survey data, and combining the active state development data to analyze the active state development mode to obtain active state soil arching evolution law data; determining an internal friction angle correction coefficient according to the active state soil arching evolution law data to form an internal friction angle correction parameter group; calculating a set of active state reinforcement factors according to the active state soil arching evolution law data and the internal friction angle correction parameter group; evaluating the wall-soil interface friction influence according to the set of active state reinforcement factors to obtain a pair of interface correction coefficients; generating an active state calibration mapping function based on the curvature pressure mapping function, the internal friction angle correction parameter group, the set of active state reinforcement factors, and the pair of interface correction coefficients; performing stress redistribution weight conversion on the active state calibration mapping function to obtain a set of stress redistribution weights; Step S4: determining a non-limiting active state according to the reference pressure grid and the set of stress redistribution weights to obtain a non-limiting active reference pressure field; performing soil pressure distribution correction processing on the non-limiting active reference pressure field using the set of stress redistribution weights to obtain a corrected soil pressure distribution map.

2. The method of claim 1, wherein, Step S1 comprises: obtaining original survey data of the terrain behind the retaining wall and performing terrain data preprocessing to obtain a terrain elevation point set; determining the geometric size of the retaining wall and establishing a wall-soil interface coordinate system in combination with the terrain elevation point set; generating a spatial discrete grid according to the wall-soil interface coordinate system; Obtaining physical parameters of soil, assigning soil parameters to spatial discrete grid to obtain parameterized grid point set; Calculating reference static earth pressure for parameterized grid point set to obtain node pressure value set; Integrating node pressure value set and spatial discrete grid to obtain reference pressure grid.

3. The method of claim 1, wherein, The soil arching effect analysis according to the curvature distribution statistical characteristics in step S3 includes: Determining the basic influence mode of terrain curvature according to the curvature distribution statistical characteristics to obtain the curvature influence basic mode; Analyzing the soil arching formation according to the curvature influence basic mode to obtain the soil arching formation condition table; Constructing a pressure transfer schematic diagram according to the soil arching formation condition table; Determining the curvature threshold value according to the pressure transfer schematic diagram to obtain the curvature threshold value quick reference table; Determining the influence range and intensity according to the curvature threshold value quick reference table and the pressure transfer schematic diagram to obtain the soil arching curvature influence law data.

4. The method of claim 1, wherein, Calculating the active state reinforcement factor set according to the active state soil arching evolution law data and the internal friction angle correction parameter group includes: Analyzing the displacement-induced soil rearrangement according to the active state soil arching evolution law data to obtain the displacement soil structure change characteristics; Processing the active state-soil arching coupling according to the displacement soil structure change characteristics to obtain the coupling data; Calculating the convex region reinforcement factor according to the coupling data and the internal friction angle correction parameter group to obtain the convex region reinforcement factor table; Calculating the concave region reinforcement factor according to the coupling data and the internal friction angle correction parameter group to obtain the concave region reinforcement factor table; Integrating and mapping the convex region reinforcement factor table and the concave region reinforcement factor table to form the active state reinforcement factor set.

5. The method of claim 1, wherein, The stress redistribution weight conversion of the active state calibration mapping function in step S3 includes: Calculating the stress redistribution coefficient according to the active state calibration mapping function and the terrain curvature spectrum to obtain the initial redistribution coefficient field; Performing boundary effect correction on the initial redistribution coefficient field to obtain the modified redistribution coefficient field; Integrating the modified redistribution coefficient field to obtain the stress redistribution weight set.

6. The method of claim 1, wherein, The non-limit active state determination according to the reference pressure grid and the stress redistribution weight set in step S4 includes: Performing data format unification and preprocessing on the reference pressure grid and the stress redistribution weight set to obtain the registration data pair; Obtaining the retaining wall design displacement data, and analyzing the wall displacement characteristics combined with the registration data pair to obtain the wall displacement distribution curve; Calculating the relative displacement ratio according to the wall displacement distribution curve to obtain the relative displacement ratio distribution map; Determining the non-limit coefficient distribution matrix according to the relative displacement ratio distribution map; Using the non-limit coefficient distribution matrix to correct the complex terrain earth pressure to obtain the terrain correction pressure coefficient field; Converting and synthesizing the non-limit active earth pressure by the non-limit active state calibration mapping function and the terrain correction pressure coefficient field to obtain the non-limit active reference pressure field.

7. The method of claim 1, wherein, The soil pressure distribution correction processing of the non-limit active reference pressure field by the stress redistribution weight set in step S4 includes: Calculating the soil pressure distribution correction according to the non-limit active reference pressure field and the stress redistribution weight set to obtain the original correction pressure field; Pressure balance check and adjustment are performed according to the original correction pressure field and the non-limiting active reference pressure field, to obtain a balanced correction pressure field; Wall surface resultant force and action point calculation are performed on the balanced correction pressure field, to obtain wall surface pressure characteristic values; After the balanced correction pressure field and the wall surface pressure characteristic values are corrected, a modified soil pressure distribution diagram is generated, to obtain a modified soil pressure distribution diagram.

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