A method for predicting geotechnical engineering stability considering the influence of karst caves

Abstract

The invention discloses a method for predicting the stability of geotechnical engineering considering the influence of karst caves. By establishing a mapping relationship between parameters related to karst caves and displacement values ​​of surface settlement and tilt displacement values ​​of foundation pit side walls, a prediction model for predicting displacement values ​​of surface settlement and tilt displacement values ​​of foundation pit side walls under the influence of karst caves is constructed. Compared with the traditional prediction model, the method transforms inequality constraints into equality constraints to predict the deformation of soil, greatly simplifies the model training process, and improves the calculation efficiency. Especially under the influence of various complex conditions in the foundation pit, the prediction process is simple and the prediction accuracy is high.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit engineering, and in particular to a method for predicting geotechnical engineering stability taking into account the influence of karst caves. Background Art

[0002] During the implementation of engineering construction, the existence of karst caves poses a major threat to foundation stability. It not only significantly weakens the bearing capacity of the foundation, but also increases the risk of settlement and deformation of the foundation, resulting in uneven settlement of the surface, which has an adverse effect on the foundation pit as a whole. In terms of the evaluation of foundation pit construction stability, especially for foundation pit construction in karst areas, relatively in-depth research has been conducted. The research content covers the geological characteristics of karst areas, the influence mechanism of karst caves on foundation pit stability, and the corresponding stability evaluation methods. The study shows that there is a certain mapping relationship between the position relationship of the karst cave and the deformation variable of the foundation pit. However, under the influence of various complex conditions in the foundation pit, the existing prediction models are mostly inequality constraints, which have the disadvantages of low efficiency and complex prediction process, and the accuracy of the predicted structure is insufficient. Summary of the invention

[0003] The invention discloses a geotechnical engineering stability prediction method considering the influence of karst caves, so as to overcome the above technical problems.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A method for predicting geotechnical engineering stability considering the influence of karst caves includes the following steps:

[0006] S1. Obtaining parameters related to the karst cave and performing preprocessing to obtain a preprocessed karst cave related data set; the parameters related to the karst cave include the diameter of the karst cave, the distance between the karst cave and the side wall of the foundation pit, the angle of the karst cave relative to the center point of the foundation pit, the deformation modulus of the rock and soil mass under the influence of the karst cave, and the Poisson's ratio of the karst cave;

[0007] S2: According to the preprocessed karst cave related data set, a mapping relationship between karst cave related parameters and displacement values ​​of surface settlement and displacement values ​​of foundation pit side wall inclination is established to establish a prediction model for predicting displacement values ​​of surface settlement and displacement values ​​of foundation pit side wall inclination under the influence of karst cave;

[0008] S3: Establishing a model error index to train a prediction model for predicting the displacement value of the surface settlement under the influence of the cave and the displacement value of the side wall inclination of the foundation pit;

[0009] S4: Obtain the parameters related to the karst caves measured at the construction site, and obtain the displacement prediction value of the surface settlement and the displacement prediction value of the foundation pit side wall inclination at the construction site according to the trained prediction model, so as to realize the prediction of the stability of geotechnical engineering considering the influence of karst caves.

[0010] Furthermore, the method for establishing the mapping relationship between the cave-related parameters and the displacement value of the surface settlement and the inclination displacement value of the foundation pit side wall is as follows:

[0011] S21: Objective function for constructing the mapping relationship between cave-related parameters and displacement values ​​of surface settlement and pit sidewall inclination displacement values:

[0012] ,

[0013] The constraints are:

[0014] ,

[0015] ,

[0016] in,

[0017] ,

[0018] Where: is the objective function value; is a space vector; is the complexity control parameter; represents the error variable; represents transpose; Indicates the total number of caves; Indicates the index number of the cave; represents a nonlinear mapping function; Indicates The diameter of a cave; Indicates The distance between the cave and the side wall of the foundation pit; Indicates The angle of each cave relative to the center of the foundation pit; Indicates The deformation modulus of the rock and soil mass under the influence of a cave; Indicates Poisson's ratio of a cave; Indicates The soil deformation vector under the influence of the cave; Indicates The displacement value of the surface settlement under the influence of the cave; Indicates The inclination displacement value of the foundation pit side wall under the influence of the karst cave; Indicates numerical deviation;

[0019] S22: constructing a T function to obtain key parameters and numerical deviations in the T function according to the objective function;

[0020] S23: According to the key parameters and numerical deviations in the T function, a mapping relationship between the parameters related to the cave and the displacement values ​​of the surface settlement and the inclination displacement values ​​of the foundation pit side wall based on nonlinear mapping is established.

[0021] Furthermore, the method for obtaining the key parameters and numerical deviations in the T function is as follows:

[0022] S221: Construct the T function as follows:

[0023] ,

[0024] Where: express function; Indicates i The key parameters in the T function under the influence of the cave; is the numerical deviation; is a space vector; represents the error variable;

[0025] S222: According to the Carlo-Kuhn-Tucker condition, Calculate partial derivatives respectively to obtain the partial derivatives of key parameters in the T function as follows;

[0026] ,

[0027] S223: Express and organize the partial derivatives of the T function using homogeneous linear equations to obtain key parameters and numerical deviations in the T function;

[0028] Among them, the partial derivative of the T function is expressed by a homogeneous linear equation and organized as follows:

[0029] ,

[0030] ,

[0031] in,

[0032] ,

[0033] ,

[0034] ,

[0035] ,

[0036] ,

[0037] Where: , , All are intermediate calculation parameters; represents the set of soil deformations under the influence of caves; is the identity matrix; Indicates the first cave and the The nonlinear mapping partition function between the caves.

[0038] Furthermore, the mapping relationship between the cave-related parameters and the displacement value of the surface settlement and the inclination displacement value of the foundation pit side wall is established as follows:

[0039] S231: Establish the initial mapping relationship as follows:

[0040] ,

[0041] Where: A mapping function representing the parameters related to the cave and the displacement values ​​of the surface settlement and the tilt displacement values ​​of the foundation pit sidewall; Indicates The soil deformation vector under the influence of the karst cave includes the displacement value of the surface settlement and the displacement value of the side wall of the foundation pit; Indicates Parameters related to caves; Indicates the index number of the cave; is a space vector; represents transpose; represents a nonlinear mapping function; is the numerical deviation, and , is a real number;

[0042] S232: According to the key parameters and numerical deviations in the T function, a mapping relationship between the parameters related to the cave based on the nonlinear mapping partition function and the displacement value of the surface settlement and the inclination displacement value of the foundation pit side wall is established as follows:

[0043] ,

[0044] ,

[0045] in,

[0046] ,

[0047] Where: represents the nonlinear mapping partition function; i , j Both represent the index number of the cave.

[0048] Furthermore, the model error index is established as follows:

[0049] ,

[0050] Where: represents the root mean square error; Relative error. is the settlement prediction data, Subsidence monitoring data.

[0051] Beneficial effects: The present invention is a method for predicting the stability of geotechnical engineering considering the influence of karst caves. By establishing a mapping relationship between the parameters related to karst caves and the displacement values ​​of surface settlement and the tilt displacement values ​​of the sidewalls of foundation pits, a prediction model for predicting the displacement values ​​of surface settlement and the tilt displacement values ​​of the sidewalls of foundation pits under the influence of karst caves is constructed. Compared with the traditional prediction model, the inequality constraint is converted into an equality constraint to predict the deformation of the soil, which greatly simplifies the model training process and improves the calculation efficiency. Especially under the influence of various complex conditions in the foundation pit, the prediction process is simple and the prediction accuracy is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor. Figure 1 It is a flow chart of the method for predicting geotechnical engineering stability of the present invention;

[0053] Figure 2 is a flow chart of a method for predicting geotechnical engineering stability in an embodiment of the present invention;

[0054] Figure 3 This is a diagram of the FLAC3D model in an embodiment of the invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] This embodiment introduces a method for predicting geotechnical engineering stability considering the influence of caves. Figure 1 and Figure 2 As shown, the following steps are included:

[0057] S1. Obtain parameters related to the karst caves at the construction site and perform preprocessing to obtain a preprocessed karst cave related data set; the parameters related to the karst caves include the diameter of the karst caves, the distance between the karst caves and the side wall of the foundation pit, the angle of the karst caves relative to the center point of the foundation pit, the deformation modulus and the Poisson's ratio.

[0058] Specifically, the cave-related parameters obtained in this embodiment are: ,in, In this embodiment, , , , , ,

[0059] in: Represents a set of parameters related to caves; Indicates Parameters related to caves; Indicates the index number of the cave;

[0060] represents the diameter set of caves; Indicates The diameter of a cave, in meters; Indicates the total number of caves; Represents the distance set between the cave and the side wall of the foundation pit; Indicates The distance between a cave and the side wall of the foundation pit, in m; Represents the angle set of the cave relative to the center point of the foundation pit; Indicates The angle of the cave relative to the center of the foundation pit. Specifically, a coordinate system with the center of the foundation pit as the origin and the horizontal axis as the reference direction is established. The unit is °; It represents the set of deformation moduli of rock and soil mass under the influence of cave, with the unit of GPa; Indicated in The deformation modulus of the rock and soil mass under the influence of a cave; represents the set of Poisson's ratios; Indicates Poisson's ratio of a cave;

[0061] In this embodiment, since it is necessary to verify the rationality and accuracy of the location of the cave, the technicians in this field pre-process the parameters related to the cave based on the common methods in the field, that is, perform data cleaning on the parameters related to the cave to ensure that the cave is located in the correct foundation pit area and does not exceed the boundary of the foundation pit. If an abnormal value is found during the processing, it needs to be corrected or deleted.

[0062] Specifically, in view of the complex and changeable characteristics of the karst cave morphology during the foundation pit excavation process, for the convenience of analysis, in this embodiment, the karst cave is simplified as a prototype structure without internal filling for processing. The diameter of the karst cave is set to D = 1, 2, 3, 4, 5, 6m, the distance between the karst cave and the side wall of the foundation pit is L = 3m, 6m, 9m, 12m, 15m, and the angle of the karst cave relative to the center point of the foundation pit is 0°, 18°, 36°, 54°, 72°, 90° respectively as input values ​​to establish The training samples of ,in , Indicates the total number of caves;

[0063] S2: Based on the preprocessed cave-related data set, a mapping relationship between cave-related parameters and the displacement values ​​of surface settlement and the displacement values ​​of the side wall inclination of the foundation pit is established, so as to establish a prediction model for predicting the displacement values ​​of surface settlement and the displacement values ​​of the side wall inclination under the influence of the cave; wherein the displacement values ​​of surface settlement and the displacement values ​​of the side wall inclination under the influence of the cave are obtained based on actual measurements.

[0064] Preferably, in S2, the mapping relationship between the parameters related to the cave and the displacement value of the surface settlement and the displacement value of the inclination of the foundation pit side wall is established as follows:

[0065] S21: Objective function for constructing the mapping relationship between cave-related parameters and displacement values ​​of surface settlement and pit sidewall inclination displacement values:

[0066] ,

[0067] The constraints are:

[0068] ,

[0069] ,

[0070] in,

[0071] ,

[0072] Where: is the objective function value; is a space vector; is the complexity control parameter; represents the error variable; represents transpose; Indicates the total number of caves; i Indicates the index number of the cave; represents a nonlinear mapping function; Indicates The diameter of a cave; Indicates The distance between the cave and the side wall of the foundation pit; Indicates The angle of each cave relative to the center of the foundation pit; Indicates The deformation modulus of the rock and soil mass under the influence of a cave; Indicates Poisson's ratio of a cave; Indicates The soil deformation vector under the influence of the cave; Indicates The displacement value of the surface settlement under the influence of the cave; Indicates The inclination displacement value of the foundation pit side wall under the influence of the karst cave;

[0073] S22: constructing a T function to obtain key parameters and numerical deviations in the T function according to the objective function;

[0074] Preferably, the method for obtaining the key parameters and numerical deviations in the T function is as follows:

[0075] S221: Construct the T function as follows:

[0076] ,

[0077] Where: express function; Indicates The influence of the cave Key parameters in the function; is the numerical deviation; is a space vector; represents the error variable;

[0078] S222: According to the KKT principle (Carlo-Kuhn-Tucker condition), Calculate partial derivatives respectively to obtain the partial derivatives of key parameters in the T function as follows;

[0079] ,

[0080] S223: Express and organize the partial derivatives of the T function using homogeneous linear equations to obtain key parameters and numerical deviations in the T function;

[0081] Among them, the partial derivative of the T function is expressed by a homogeneous linear equation and organized as follows:

[0082] ,

[0083] in,

[0084] ,

[0085] ,

[0086] ,

[0087] ,

[0088] ,

[0089] Where: , , All are intermediate calculation parameters; represents the set of soil deformations under the influence of caves; is the identity matrix; Indicates the first cave and the The nonlinear mapping partition function between the caves.

[0090] Furthermore, the mapping relationship between the cave-related parameters and the displacement value of the surface settlement and the inclination displacement value of the foundation pit side wall is established as follows:

[0091] S23: According to the key parameters and numerical deviations in the T function, a mapping relationship between the parameters related to the cave and the displacement values ​​of the surface settlement and the inclination displacement values ​​of the foundation pit side wall based on nonlinear mapping is established; the method is as follows:

[0092] S231: Establish the initial mapping relationship as follows:

[0093] ,

[0094] Where: ,

[0095] Where: A mapping function representing the parameters related to the cave and the displacement values ​​of the surface settlement and the tilt displacement values ​​of the foundation pit sidewall; Indicates The soil deformation vector under the influence of the karst cave includes the displacement value of the surface settlement and the displacement value of the side wall of the foundation pit; Indicates Parameters related to caves; Indicates the index number of the cave; is a space vector; represents transpose; represents a nonlinear mapping function; is the numerical deviation, and , is a real number;

[0096] S232: According to the key parameters and numerical deviations in the T function, a mapping relationship between the parameters related to the cave based on the nonlinear mapping partition function and the displacement value of the surface settlement and the inclination displacement value of the foundation pit side wall is established as follows:

[0097] ,

[0098] ,

[0099] in,

[0100] ,

[0101] Where: represents the nonlinear mapping partition function; i , j Both represent the index number of the cave.

[0102] At this point, the test sample is obtained , α, E, and μ. According to the mapping relationship between the established parameters related to the cave and the displacement value of the surface settlement and the tilt displacement value of the side wall of the foundation pit, the mapping relationship between the diameter of the cave, the distance between the cave and the foundation pit, the surface settlement, and the horizontal displacement value of the side wall can be obtained, so as to realize the rapid and accurate identification of the influence of the deformation of the foundation pit in the actual foundation pit project.

[0103] S3: Establishing a model error index to train a prediction model for predicting the displacement value of the surface settlement under the influence of the cave and the displacement value of the side wall inclination of the foundation pit;

[0104] Preferably, the model error index is established as follows:

[0105] ,

[0106] Where: represents the root mean square error; Relative error. y 3 is the settlement prediction data, y 4. Settlement monitoring data;

[0107] In this embodiment, when the root mean square error and the relative error are both less than the set threshold, the training of the model is terminated. Specifically, the closer the values ​​of the two are to 0, the higher the accuracy and the better the prediction effect.

[0108] S4: Obtain the parameters related to the karst caves measured at the construction site, and obtain the displacement prediction values ​​of the surface settlement and the displacement prediction values ​​of the side wall inclination of the foundation pit at the construction site based on the trained prediction model of the displacement values ​​of the surface settlement and the displacement values ​​of the side wall inclination under the influence of the karst caves, so as to realize the prediction of the stability of geotechnical engineering considering the influence of the karst caves.

[0109] A specific embodiment of the present invention is as follows:

[0110] Construct simulated data with a capacity of 30 , the data set comes from FLAC3D numerical simulation, such as Figure 3 shown. represents the training data set; Represents a set of parameters related to caves; Y represents the set of soil deformations under the influence of caves;

[0111] in, , The input data is 30 times. , Output data for 30 times; , is the deformation modulus of 30 times; , is the Poisson's ratio of 30 times; as shown in Table 1; since the foundation pit in the selected area is a symmetrical foundation pit, only one side is selected as the measurement object, and , All are in positive direction;

[0112] Table 1:

[0113] factor <![CDATA[x R (m)]]> <![CDATA[x d (m)]]> α(°) E(GPa) μ <![CDATA[y1(mm)]]> <![CDATA[y2(mm)]]> Data 1 1 3 0 1 0.3 6.82 2.34 Data 2 2 3 18 2 0.33 7.12 2.27 Data 3 3 3 36 3 0.36 7.52 2.02 Data 4 4 3 54 4 0.39 7.72 2.01 Data 5 5 3 72 5 0.42 7.81 1.98 Data 6 6 3 90 6 0.45 7.85 1.95 Data 7 1 6 0 1 0.3 6.44 2.34 Data 8 2 6 18 2 0.33 6.71 2.32 Data 9 3 6 36 3 0.36 6.92 2.29 Data 10 4 6 54 4 0.39 7.02 2.24 Data 11 5 6 72 5 0.42 7.08 2.18 Data 12 6 6 90 6 0.45 7.12 2.16 Data 13 1 9 0 1 0.3 6.42 2.33 Data 14 2 9 18 2 0.33 6.52 2.35 Data 15 3 9 36 3 0.36 6.62 2.38 Data 16 4 9 54 4 0.39 6.72 2.42 Data 17 5 9 72 5 0.42 6.79 2.44 Data 18 6 9 90 6 0.45 6.81 2.45 Data 19 1 12 0 1 0.3 6.39 2.28 Data 20 2 12 18 2 0.33 6.42 2.37 Data 21 3 12 36 3 0.36 6.45 2.43 Data 22 4 12 54 4 0.39 6.47 2.53 Data 23 5 12 72 5 0.42 6.48 2.56 Data 24 6 12 90 6 0.45 6.49 2.58 Data 25 1 15 0 1 0.3 6.31 2.27 Data 26 2 15 18 2 0.33 6.38 2.36 Data 27 3 15 36 3 0.36 6.44 2.44 Data 28 4 15 54 4 0.39 6.47 2.54 Data 29 5 15 72 5 0.42 6.49 2.61 Data 30 6 15 90 6 0.45 6.51 2.65

[0114] ,

[0115] ,

[0116] ,

[0117] ;

[0118] The foundation pit deformation prediction model is combined with the actual measurement of the foundation pit of Jinzhou Gold Medal Education Park. The total depth of the foundation pit is 18m, the width of the foundation pit is 40m, and the length is 40m. According to the actual measurement of the size of the cave, the distance from the center of the cave to the geometric center of the foundation pit, the deformation modulus, and the Poisson's ratio, the X =(3.75,6.33,35,2.75,0.35), surface settlement displacement value and foundation pit side wall inclination displacement value y 4=(6.88,2.31); then input the X value into the model and construct the objective function:

[0119] ,

[0120] The constraints are:

[0121] ,

[0122] According to the T function, according to the KKT principle Solve the partial derivatives separately, express and organize them with homogeneous linear equations, and finally find the numerical deviation p and key parameters q i The numerical deviation constrained by the above constraints p And the key parameters obtained in the subsequent formula q i , which better meets the requirements of subsequent calculations; , , ;

[0123] After solving the equations, the regression function of the foundation pit shape variable is obtained: ,

[0124] Obtain the deformation, surface settlement displacement and foundation pit side wall tilt displacement y3=(6.95,2.26)

[0125] The root mean square error calculated by the root mean square formula is 0.06mm. The relative error calculated by the relative error formula is 1.59%, which is less than 10%. Therefore, the prediction results of the model are highly accurate. In actual engineering applications, compared with ordinary prediction models, it can more accurately predict the deformation of the foundation pit based on various parameters of the cave, thereby realizing foundation pit safety warning and avoiding safety accidents caused by foundation pit deformation.

[0126] This embodiment can realize the rapid identification of the deformation of the foundation pit by the location of the cave in the actual project. By simulating the relationship between the location of the cave and the surface settlement and the side wall inclination, it can provide effective treatment methods and preventive measures in engineering applications, thereby reducing the safety hazards such as side wall inclination and collapse caused by the cave during the foundation pit construction process, ensuring the safety of construction personnel and reducing the probability of engineering accidents. The innovative results of this embodiment show broad application potential in many fields such as geotechnical engineering and geological engineering. Through continuous learning and technical optimization, it is possible to deepen the understanding of the complex and changeable foundation pit environment and improve the accuracy of prediction, thereby ensuring the smooth progress of the construction process and the stability and reliability of the final results.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for predicting geotechnical engineering stability considering the influence of karst caves, characterized in that: The steps include: S1. Obtaining parameters related to the karst cave and performing preprocessing to obtain a preprocessed karst cave related data set; the parameters related to the karst cave include the diameter of the karst cave, the distance between the karst cave and the side wall of the foundation pit, the angle of the karst cave relative to the center point of the foundation pit, the deformation modulus of the rock and soil mass under the influence of the karst cave, and the Poisson's ratio of the karst cave; S2: According to the preprocessed karst cave related data set, a mapping relationship between karst cave related parameters and displacement values ​​of surface settlement and displacement values ​​of foundation pit side wall inclination is established to establish a prediction model for predicting displacement values ​​of surface settlement and displacement values ​​of foundation pit side wall inclination under the influence of karst cave; S3: Establishing a model error index to train a prediction model for predicting the displacement value of the surface settlement under the influence of the cave and the displacement value of the side wall inclination of the foundation pit; S4: Obtain the parameters related to the karst caves measured at the construction site, and obtain the displacement prediction value of the surface settlement and the displacement prediction value of the foundation pit side wall inclination at the construction site according to the trained prediction model, so as to realize the prediction of the stability of geotechnical engineering considering the influence of karst caves.

2. A method for predicting geotechnical engineering stability considering the influence of karst caves according to claim 1, characterized in that: The method for establishing the mapping relationship between the cave-related parameters and the displacement value of the surface settlement and the inclination displacement value of the foundation pit side wall is as follows: S21: Objective function for constructing the mapping relationship between cave-related parameters and displacement values ​​of surface settlement and pit sidewall inclination displacement values: ， The constraints are: ， ， in, ， Where: is the objective function value; is a space vector; is the complexity control parameter; represents the error variable; represents transpose; Indicates the total number of caves; Indicates the index number of the cave; represents a nonlinear mapping function; Indicates The diameter of a cave; Indicates The distance between the cave and the side wall of the foundation pit; Indicates The angle of each cave relative to the center of the foundation pit; Indicates The deformation modulus of the rock and soil mass under the influence of a cave; Indicates Poisson's ratio of a cave; Indicates The soil deformation vector under the influence of the cave; Indicates Displacement value of surface settlement under the influence of a cave; Indicates The inclination displacement value of the foundation pit side wall under the influence of the karst cave; Indicates numerical deviation; S22: constructing a T function to obtain key parameters and numerical deviations in the T function according to the objective function; S23: According to the key parameters and numerical deviations in the T function, a mapping relationship between the parameters related to the cave and the displacement values ​​of the surface settlement and the inclination displacement values ​​of the foundation pit side wall based on nonlinear mapping is established.

3. A method for predicting geotechnical engineering stability considering the influence of karst caves according to claim 2, characterized in that: The method to obtain the key parameters and numerical deviations in the T function is as follows: S221: Construct the T function as follows: ， Where: express function; Indicates i The key parameters in the T function under the influence of the cave; is the numerical deviation; is a space vector; represents the error variable; S222: According to the Carlo-Kuhn-Tucker condition, Calculate partial derivatives respectively to obtain the partial derivatives of key parameters in the T function as follows; ， S223: The partial derivatives of the function are expressed as homogeneous linear equations and sorted to obtain Key parameters and numerical deviations in functions; Among them, the partial derivative of the T function is expressed by a homogeneous linear equation and organized as follows: ， ， in, ， ， ， ， ， Where: , , All are intermediate calculation parameters; represents the set of soil deformations under the influence of caves; is the identity matrix; Indicates the first cave and the n The nonlinear mapping partition function between the caves.

4. A method for predicting geotechnical engineering stability considering the influence of karst caves according to claim 1, characterized in that: The mapping relationship between the cave-related parameters and the displacement value of the surface settlement and the inclination displacement value of the foundation pit side wall is established as follows: S231: Establish the initial mapping relationship as follows: ， Where: A mapping function representing the parameters related to the cave and the displacement values ​​of the surface settlement and the tilt displacement values ​​of the foundation pit sidewall; Indicates The soil deformation vector under the influence of the karst cave includes the displacement value of the surface settlement and the displacement value of the side wall of the foundation pit; Indicates Parameters related to caves; Indicates the index number of the cave; is a space vector; represents transpose; represents a nonlinear mapping function; is the numerical deviation, and , is a real number; S232: According to the key parameters and numerical deviations in the T function, a mapping relationship between the parameters related to the cave based on the nonlinear mapping partition function and the displacement value of the surface settlement and the inclination displacement value of the foundation pit side wall is established as follows: ， ， ， in, ， Where: represents the nonlinear mapping partition function; i , j Both represent the index number of the cave.

5. A method for predicting geotechnical engineering stability considering the influence of karst caves according to claim 1, characterized in that: The model error index is established as follows: ， Where: represents the root mean square error; Relative error. is the settlement prediction data, It is the settlement monitoring data.

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