A simulation test method for pile-foundation soil interaction model

Abstract

The invention discloses a simulation test method for a pile foundation soil interaction model, comprising obtaining basic parameter information and engineering monitoring data of the pile foundation soil, performing finite element simulation of the pile foundation soil interaction to obtain a finite element simulation data set {A}, obtaining an engineering monitoring data set {B}, calculating an actual engineering data set {C}, calculating a deviation factor and a comprehensive similarity, constructing a pile foundation soil interaction model according to the deviation factor, the comprehensive similarity and the actual engineering data set {C}, and inputting the basic parameter information of the pile foundation soil to be simulated into the pile foundation soil interaction model to obtain the pile foundation soil interaction situation. The method can not only improve the efficiency and accuracy of the simulation test of the pile foundation soil interaction model and ensure the accuracy and reliability of the engineering design, but also has good interpretability and can be directly applied to the simulation test system of the pile foundation soil interaction model.

Description

Technical Field

[0001] The invention relates to the fields of civil engineering and geological engineering, and in particular to a simulation test method for a pile foundation-soil interaction model. Background Art

[0002] As the basic structure of a building, the stability of the pile foundation is closely related to the interaction between the pile foundation and the soil. These factors directly affect the safety and economy of the project. With the development of computer technology, the finite element simulation method has become an important means to study complex engineering problems. By constructing an accurate finite element model, the interaction process between the pile foundation and the soil under different working conditions can be simulated, providing a scientific basis for engineering design and construction.

[0003] The interaction between pile foundation and soil involves complex physical and mechanical processes, including the bearing capacity of pile foundation, settlement characteristics and nonlinear behavior of soil, etc., while the traditional pile foundation design method is often based on empirical formulas and simplified mechanical models, which is difficult to accurately reflect the complex interaction mechanism between pile foundation and soil. At the same time, most of the existing finite element simulation methods are based on idealized assumptions and lack effective integration with actual engineering data, resulting in a large deviation between the simulation results and the actual situation. Therefore, combining finite element simulation methods and machine learning, a simulation test method for the pile foundation-soil interaction model that can accurately simulate and process the pile foundation-soil interaction in combination with actual engineering data is designed to overcome the shortcomings of the existing simulation test methods, which is of great significance to improving the accuracy and reliability of engineering design. Summary of the invention

[0004] The purpose of the present invention is to provide a simulation test method for a pile foundation-soil interaction model.

[0005] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0006] The present invention comprises the following steps:

[0007] Obtaining basic parameter information and engineering monitoring data of pile foundation soil, and preprocessing the basic parameter information and the engineering monitoring data; the basic parameter information includes pile foundation parameters and soil parameters;

[0008] Constructing a pile foundation finite element model according to the pile foundation parameters, constructing a soil constraint finite element model according to the soil parameters, and performing pile foundation soil interaction finite element simulation to obtain a finite element simulation data set {A};

[0009] Inputting the engineering monitoring data into the pile foundation soil layer interaction formula to obtain an engineering monitoring data set {B}, and obtaining an actual engineering data set {C} according to the engineering monitoring data set {B};

[0010] Determine a deviation factor based on the finite element simulation data set {A} and the actual engineering data set {C}, and determine a comprehensive similarity based on the actual engineering data set {C};

[0011] A pile foundation soil interaction model is constructed according to the deviation factor, the comprehensive similarity and the finite element simulation data set {A}, and basic parameter information of the pile foundation soil to be simulated and tested is input into the pile foundation soil interaction model to obtain the pile foundation soil interaction situation.

[0012] Furthermore, the method for obtaining the basic parameter information includes:

[0013] Obtain pile foundation parameters, determine pile foundation dimensions through drawings, calculate pile top loads based on building information, and obtain elastic modulus and Poisson's ratio of pile foundation concrete and steel bars through geotechnical tests; the pile foundation parameters include pile foundation dimensions, pile top loads, elastic modulus and Poisson's ratio of pile foundation concrete and steel bars;

[0014] Obtain soil parameters, determine the calculation depth and sparse drilling depth based on the length of the pile foundation, perform sparse drilling on the soil layer to determine the soil stratification and take soil samples from different layers;

[0015] Geotechnical tests are carried out on soil samples of different layers to obtain the density, elastic modulus and Poisson's ratio of the soil layer; the soil parameters include the density, elastic modulus, Poisson's ratio, strength and stratification of the soil layer.

[0016] Furthermore, the method of performing finite element simulation of pile-foundation soil interaction to obtain the finite element simulation data set {A} comprises:

[0017] The pile-soil interaction model adopts a separated modeling method, and the top of the pile foundation cap is flush with the soil surface;

[0018] Construct a finite element model of the pile foundation, determine the simulation form of the pile foundation and the cap, determine the cell type and mesh division of concrete and steel bars according to the pile foundation size, determine the constraint conditions of the pile foundation according to the simulation background, and determine the model size and material parameters according to the pile foundation parameters;

[0019] Construct a soil-constrained finite element model, determine the cell type and mesh division of the soil layer according to the pile foundation size and soil stratification, determine the soil layer constraints according to the simulation background, and determine the model depth and material parameters according to the soil parameters;

[0020] Determine the contact mode between the pile foundation and the soil, set the contact surface and determine the contact parameters, apply the load according to the pile foundation parameters to perform finite element simulation of the pile foundation-soil interaction to obtain a finite element simulation data set {A};

[0021] The finite element simulation data set {A} includes soil layer stress distribution, soil layer displacement, pile foundation stress distribution, pile foundation displacement, pile foundation bending moment and pile foundation-soil interaction force; the pile foundation-soil interaction force includes pile foundation soil layer relative extrusion force and pile foundation soil layer friction force.

[0022] Furthermore, the method of inputting the engineering monitoring data into the pile foundation soil layer interaction formula to obtain the engineering monitoring data set {B} comprises:

[0023] Acquiring engineering monitoring data through strain gauges, pressure sensors and laser rangefinders; the engineering monitoring data includes soil layer stress distribution, soil layer displacement, pile foundation compressive stress distribution and pile foundation displacement;

[0024] The pile foundation-soil layer interaction formula includes an expression for the relative squeezing force of the pile foundation-soil layer and an expression for the friction force of the pile foundation-soil layer;

[0025] The relative squeezing pressure of the pile foundation soil layer is calculated based on the engineering monitoring data. The relative squeezing pressure of the pile foundation soil layer is expressed as:

[0026]

[0027] Where P(x,y) is the relative squeezing pressure of the soil layer inside the pile foundation per unit area, z is the depth below the surface, x and y are horizontal positions, k(z) is the foundation coefficient, and n is an exponent. k(z) and n vary with z. is the horizontal displacement of the pile foundation p Horizontal displacement of soil layer s The difference between the pile foundation and the soil layer is E sr is the elastic modulus of the reference soil layer, E s is the elastic modulus of the soil layer, [I] is the influence coefficient matrix, σ s is the soil stress around the pile foundation;

[0028] The friction force of the pile foundation soil layer is calculated based on the engineering monitoring data. The friction force of the pile foundation soil layer is expressed as:

[0029]

[0030] Where f(z) is the friction force of the inner pile foundation soil layer at depth z, P is the relative extrusion force of the inner pile foundation soil layer per unit area, θ is the basic friction angle, is the roughness coefficient of the soil layer, τ s is the peak shear strength of the soil layer, and JCS is the compressive strength of the soil layer;

[0031] The engineering monitoring data, the relative squeezing force of the pile foundation soil layer and the friction force of the pile foundation soil layer form the engineering monitoring data set {B}.

[0032] Furthermore, the method for obtaining the actual engineering data set {C} according to the engineering monitoring data set {B} includes:

[0033] Calculate the initial horizontal displacement y0 of the pile foundation and the initial rotation angle of the pile foundation at the ground according to the engineering monitoring data set {B} The expression is:

[0034]

[0035] Where y0 is the initial horizontal displacement of the pile foundation, is the initial rotation angle of the pile foundation at the ground, F p ′ is the unit horizontal force at the top of the pile foundation, M p ′ is the unit bending moment at the top of the pile foundation, and only the unit horizontal force F acts on the top of the pile foundation p ′ = 1, the horizontal displacement and rotation angle of the pile foundation at the ground are δ y1 and Only unit bending moment M acts on the top of the pile foundation p ′ = 1, the horizontal displacement and rotation angle of the pile foundation at the ground are δ y2 and

[0036] The pile foundation bending moment and pile foundation shear stress are calculated based on the initial horizontal displacement of the pile foundation and the initial rotation angle of the pile foundation at the ground. The expressions are:

[0037]

[0038] Where M(z) is the bending moment of the pile foundation at depth z, Q(z) is the shear stress of the pile foundation at depth z, y0 is the initial horizontal displacement of the pile foundation, α is the deformation coefficient of the pile foundation, E is the elastic modulus of the pile foundation, and I is the moment of inertia of the pile foundation section at depth z. is the initial rotation angle of the pile foundation at the ground, M p is the bending moment at the top of the pile foundation, F p is the horizontal force on the top of the pile foundation, A1, B1, C1, D1 are the coefficients with a dimension of 1 for calculating the bending moment of the pile foundation, and A2, B2, C2, D2 are the coefficients with a dimension of 1 for calculating the shear stress of the pile foundation;

[0039] The pile foundation bending moment, pile foundation shear stress and engineering monitoring data set {B} are combined into the actual engineering data set {C}.

[0040] Further, the method for determining the deviation factor includes:

[0041] Calculate the deviation between the finite element simulation value and the actual measurement value according to the finite element simulation data set {A} and the actual engineering data set {C} to obtain deviation data; the deviation data includes the relative displacement deviation of the pile foundation soil layer, the effective stress deviation of the soil layer, the shear stress deviation of the soil layer, the shear stress deviation of the pile foundation, the bending moment deviation of the pile foundation soil layer, the relative extrusion pressure deviation of the pile foundation soil layer and the friction deviation of the pile foundation soil layer;

[0042] The deviation factor includes a first deviation factor and a second deviation factor;

[0043] The relative displacement deviation of the pile foundation soil layer, the effective stress deviation of the soil layer and the relative extrusion pressure deviation of the pile foundation soil layer are input into the first deviation function to obtain the first deviation factor, which is expressed as:

[0044]

[0045] Where D1 is the first deviation factor, Δy is the relative displacement deviation of the pile foundation soil layer, ΔU is the effective stress deviation of the soil layer, ΔP is the relative extrusion pressure deviation of the pile foundation soil layer, and u Δy is the mean relative displacement deviation of the pile foundation soil layer, u ΔU is the mean deviation of effective stress of soil layer, u ΔP is the mean deviation of relative extrusion pressure of pile foundation soil layer, σ Δy is the standard deviation of the relative displacement of the pile foundation soil layer, σ ΔU is the standard deviation of soil effective stress, σ total is the total standard deviation of all deviations, w1 and w2 are the deviation weight coefficients;

[0046] The soil shear stress deviation, pile foundation shear stress deviation, pile foundation soil relative displacement deviation and pile foundation soil friction deviation are input into the second deviation function to obtain the second deviation factor, which is expressed as:

[0047]

[0048] Where D2 is the second deviation factor, Δf is the friction deviation of the pile foundation soil layer, and u Δf is the mean value of the friction deviation of the pile foundation soil layer, τ s is the soil shear stress deviation, τ p Pile foundation shear stress deviation, w3, w4, w5 are deviation weight coefficients.

[0049] Furthermore, the method for determining the comprehensive similarity includes:

[0050] The relative displacement deviation characteristic vector of the pile foundation soil layer is defined as y = [y1, y2, …, y i ,…,y n ], the characteristic vector of the friction deviation of the pile foundation soil layer is f = [f1,f2,…,f i ,…,f n], the soil shear stress deviation characteristic vector is τ=[τ1,τ2,…,τ i ,…,τ n ], the characteristic vector of pile foundation bending moment deviation is m = [m1, m2, …, m i ,…,m n ], n is the length of the feature vector;

[0051] The Euclidean distance d between the relative displacement deviation characteristic vector of the pile foundation soil layer and the friction deviation characteristic vector of the pile foundation soil layer is calculated. ed (y,f), the Euclidean distance d between the characteristic vector of soil shear stress deviation and the characteristic vector of pile foundation bending moment deviation ed (τ,m);

[0052] Calculate the first-order difference sequence x of all data diff =[x diff 1,x diff 2,…,x diff i ,…,x diff n-1 ], where x diff i =x diff i+1 -x diff i is the first-order difference value, x∈{y,f,τ,m}, and the dynamic time bending distance d between the relative displacement deviation characteristic vector of the pile foundation soil layer and the friction deviation characteristic vector of the pile foundation soil layer is calculated according to the first-order difference sequence DTW (y diff , f diff ), the dynamic time bending distance d between the characteristic vector of soil shear stress deviation and the characteristic vector of pile foundation bending moment deviation DTW (τ diff , mf diff );

[0053] The comprehensive similarity is calculated based on the Euclidean distance and the dynamic time warping distance. The expression is:

[0054]

[0055] Among them, S is the comprehensive similarity, a1, b1, a2, and b2 are the weight coefficients of similarity indicators, which are determined by the entropy weight method.

[0056] Furthermore, the method for obtaining the pile foundation soil interaction condition includes:

[0057] A comprehensive feature set is obtained by selecting features of the deviation factor, comprehensive similarity and finite element simulation data set {A}, and the comprehensive feature set is divided into a training set and a test set; the comprehensive feature set includes the deviation factor, comprehensive similarity, relative squeezing force of pile foundation soil layer, friction force of pile foundation soil layer and pile foundation bending moment;

[0058] A pile-soil interaction model is constructed based on physical information neural network, including input layer, hidden layer and output layer;

[0059] The characteristic data of the training set enters the hidden layer through the input layer for learning. The hidden layer sets multiple fully connected layers and uses the ReLu activation function to assist prediction. The prediction results are output through the output layer. The prediction results include the predicted value of the relative squeezing pressure of the pile foundation soil layer, the predicted value of the friction force of the pile foundation soil layer, and the predicted value of the pile foundation bending moment.

[0060] The loss function includes a data fitting term and a physical consistency term. The data fitting term uses the mean square error to evaluate the difference between the predicted value and the true value. The physical consistency term uses the pile foundation-soil layer interaction formula and the pile foundation bending moment expression to ensure the physical interpretability of the predicted value. The Adamax optimizer is used to optimize the weight of the pile foundation-soil interaction model, and the test set is used to evaluate the pile foundation-soil interaction model.

[0061] The basic parameter information of the pile foundation soil to be simulated and tested is input into the pile foundation soil interaction model to obtain the pile foundation soil interaction situation.

[0062] The beneficial effects of the present invention are:

[0063] The present invention is a simulation test method for a pile foundation soil interaction model. Compared with the prior art, the present invention has the following technical effects:

[0064] The present invention can improve the data preprocessing capability and enhance the model adaptability in the simulation test of the pile foundation soil interaction model through finite element simulation, engineering monitoring data acquisition and processing, determination of deviation factors, determination of comprehensive similarity, and model construction steps, thereby improving the efficiency and accuracy of the simulation test of the pile foundation soil interaction model, and optimizing the simulation test technology of the pile foundation soil interaction model, which can greatly save resources and improve work efficiency, and can achieve accurate simulation of the pile foundation soil interaction model, providing a more scientific and reliable basis for engineering design and construction, which is of great significance to improving the accuracy and reliability of engineering design, and can adapt to the simulation test evaluation systems of different pile foundation soil interaction models and the terminal simulation test requirements of the simulation test systems of the pile foundation soil interaction models of different users, and has a certain universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1The present invention is a flowchart of the steps of a simulation test method for a pile foundation soil interaction model. DETAILED DESCRIPTION

[0066] The present invention is further described below by means of specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0067] A simulation test method for a pile foundation soil interaction model of the present invention comprises the following steps:

[0068] like Figure 1 As shown, in this embodiment, the following steps are included:

[0069] Obtaining basic parameter information and engineering monitoring data of pile foundation soil, and preprocessing the basic parameter information and the engineering monitoring data; the basic parameter information includes pile foundation parameters and soil parameters;

[0070] Constructing a pile foundation finite element model according to the pile foundation parameters, constructing a soil constraint finite element model according to the soil parameters, and performing pile foundation soil interaction finite element simulation to obtain a finite element simulation data set {A};

[0071] Inputting the engineering monitoring data into the pile foundation soil layer interaction formula to obtain an engineering monitoring data set {B}, and obtaining an actual engineering data set {C} according to the engineering monitoring data set {B};

[0072] Determine a deviation factor based on the finite element simulation data set {A} and the actual engineering data set {C}, and determine a comprehensive similarity based on the actual engineering data set {C};

[0073] A pile foundation soil interaction model is constructed according to the deviation factor, the comprehensive similarity and the finite element simulation data set {A}, and basic parameter information of the pile foundation soil to be simulated and tested is input into the pile foundation soil interaction model to obtain the pile foundation soil interaction situation.

[0074] In this embodiment, the method for obtaining the basic parameter information includes:

[0075] Obtain pile foundation parameters, determine pile foundation dimensions through drawings, calculate pile top loads based on building information, and obtain elastic modulus and Poisson's ratio of pile foundation concrete and steel bars through geotechnical tests; the pile foundation parameters include pile foundation dimensions, pile top loads, elastic modulus and Poisson's ratio of pile foundation concrete and steel bars;

[0076] Obtain soil parameters, determine the calculation depth and sparse drilling depth based on the length of the pile foundation, perform sparse drilling on the soil layer to determine the soil stratification and take soil samples from different layers;

[0077] Conducting geotechnical tests on soil samples of different layers to obtain the density, elastic modulus and Poisson's ratio of the soil layer; the soil parameters include the density, elastic modulus, Poisson's ratio, strength and stratification of the soil layer;

[0078] In the actual evaluation, a set of corresponding pile foundation parameters and soil parameters were obtained by taking a 25-story residential area in the south as an example: (pile foundation parameters: pile foundation length 30m, pile top uniform load 1.2MPa, concrete elastic modulus 30GPa and Poisson's ratio 0.2, steel elastic modulus 210GPa and Poisson's ratio 0.3); (soil parameters: 1. Cover layer - miscellaneous fill silty clay: total thickness 3m, density 1900kg / m 3 , elastic modulus 15MPa, Poisson's ratio 0.3; 2. Main bearing layer - medium sand clay mixed layer: total thickness 15m, density 2025kg / m 3 , elastic modulus 35MPa, Poisson's ratio 0.26; 3. Pile end bearing layer: total thickness 7m, density 2600kg / m 3 , elastic modulus 500MPa, Poisson's ratio 0.2, compressive strength 30MPa).

[0079] In this embodiment, the method of performing finite element simulation of pile-foundation-soil interaction to obtain the finite element simulation data set {A} includes:

[0080] The pile-soil interaction model adopts a separated modeling method, where the top of the cap is flush with the soil surface;

[0081] Construct a finite element model of the pile foundation. The pile foundation is simulated by using displacement-based fiber units and the cap is simulated by using elastic beam units. The concrete is modeled by using Solid164 units and the steel bars are modeled by using Beam161 units. The pile foundation is divided into multiple units along the height direction. The concrete is divided into hexahedral grids with a size of 1 / 10 of the pile foundation diameter and the steel bars are divided into tetrahedral grids with a size of 1 mm. The model size and material parameters are determined according to the pile foundation parameters, and the boundary conditions at the bottom of the pile foundation are set as fixed constraints.

[0082] A soil constrained finite element model was constructed. The soil layer was divided into square grids with a size of 20 mm using the modified Cambridge model unit. The bottom of the soil layer was set as a fixed constraint and the side was set as a non-reflecting boundary. The model size and material parameters were determined according to the soil parameters.

[0083] The pile foundation and soil are connected in a common node manner to simulate the interaction, the contact surface is set and the contact parameters are determined, and the pile foundation soil interaction finite element simulation is performed according to the pile foundation parameters to obtain the finite element simulation data set;

[0084] The finite element simulation data set includes soil layer stress distribution, soil layer displacement, pile foundation stress distribution, pile foundation displacement, pile foundation bending moment and pile foundation soil interaction force; the pile foundation soil interaction force includes pile foundation soil layer relative extrusion force and pile foundation soil layer friction force;

[0085] In the actual evaluation, the finite element simulation of the pile foundation and soil of a 25-story residential area in the south was carried out, and a set of finite element simulation data sets were obtained: (cover layer: 1. The average shear stress of the soil layer is 5kPa, the effective stress is 50kPa, the horizontal displacement is 5mm, and the vertical displacement is 10mm; 2. The pile foundation stress is 10MPa, the horizontal displacement is 1.5mm, the vertical displacement is 3mm, and the bending moment is 10kNm; 3. The mutual squeezing force of the pile foundation soil layer is 200kPa, and the friction force is 50kPa), (main bearing layer: 1. The average shear stress of the soil layer is 20kPa, the effective stress is 200kPa, and the horizontal displacement is 10mm. displacement 3mm, vertical displacement 5mm; 2. Pile foundation stress 15MPa, horizontal displacement 0.5mm, vertical displacement 2mm, bending moment 50kNm; 3. Mutual squeezing force of pile foundation soil layers 300kPa, friction 100kPa), (pile end bearing layer: 1. Average shear stress of soil layer 30kPa, effective stress 400kPa, horizontal displacement 1mm, vertical displacement 0mm; 2. Pile foundation stress 20MPa, horizontal displacement 0mm, vertical displacement 0mm, bending moment -30kNm; 3. Mutual squeezing force of pile foundation soil layers 400kPa, friction 20kPa).

[0086] In this embodiment, the method of inputting the engineering monitoring data into the pile foundation soil layer interaction formula to obtain the engineering monitoring data set {B} includes:

[0087] Acquiring engineering monitoring data through strain gauges, pressure sensors and laser rangefinders; the engineering monitoring data includes soil layer stress distribution, soil layer displacement, pile foundation compressive stress distribution and pile foundation displacement;

[0088] The pile foundation-soil layer interaction formula includes an expression for the relative squeezing force of the pile foundation-soil layer and an expression for the friction force of the pile foundation-soil layer;

[0089] The relative squeezing pressure of the pile foundation soil layer is calculated based on the engineering monitoring data. The relative squeezing pressure of the pile foundation soil layer is expressed as:

[0090]

[0091] Where P(x,y) is the relative squeezing pressure of the soil layer inside the pile foundation per unit area, z is the depth below the surface, x and y are horizontal positions, k(z) is the foundation coefficient, and n is an exponent. k(z) and n vary with z. is the horizontal displacement of the pile foundation p Horizontal displacement of soil layer s The difference between the pile foundation and the soil layer is Esr is the elastic modulus of the reference soil layer, E s is the elastic modulus of the soil layer, [I] is the influence coefficient matrix, σ s is the soil stress around the pile foundation;

[0092] The friction force of the pile foundation soil layer is calculated based on the engineering monitoring data. The friction force of the pile foundation soil layer is expressed as:

[0093]

[0094] Where f(z) is the friction force of the inner pile foundation soil layer at depth z, P is the relative extrusion force of the inner pile foundation soil layer per unit area, θ is the basic friction angle, is the roughness coefficient of the soil layer, τ s is the peak shear strength of the soil layer, and JCS is the compressive strength of the soil layer;

[0095] The engineering monitoring data, the relative squeezing force of the pile foundation soil layer and the friction force of the pile foundation soil layer are combined into an engineering monitoring data set {B};

[0096] In the actual assessment, the engineering monitoring data of a 25-story residential area in the south were obtained: (cover layer: 1. average soil shear stress 4.5kPa, effective stress 45kPa, horizontal displacement 4.2mm, vertical displacement 8.5mm; 2. pile foundation stress 12MPa, horizontal displacement 1.8mm, vertical displacement 5mm), (main bearing layer: 1. average soil shear stress 18kPa, effective stress 180kPa, horizontal displacement 2.1mm, vertical displacement 4.5mm; 2. pile foundation stress 17MPa, horizontal displacement 0.5mm, vertical displacement 2.4mm), (pile end bearing layer: 1. average soil shear stress 28kPa, effective stress 360kPa, horizontal displacement 0mm, vertical displacement 0mm; 2. pile foundation stress 25MPa, horizontal displacement 0mm, vertical displacement 0mm).

[0097] Substitute the acquired engineering monitoring data into the pile foundation-soil layer interaction formula to calculate the pile foundation-soil layer interaction force of each soil layer: (cover layer: pile foundation soil layer mutual squeezing force 180 kPa, friction force 60 kPa), (main bearing layer: pile foundation soil layer mutual squeezing force 320 kPa, friction force 120 kPa), (pile end bearing layer: pile foundation soil layer mutual squeezing force 450 kPa, friction force 60 kPa), and combine the pile foundation-soil layer interaction force calculation data of each soil layer with the acquired engineering monitoring data to form the engineering monitoring data set {B}.

[0098] In this embodiment, the method for obtaining the actual engineering data set {C} according to the engineering monitoring data set {B} includes:

[0099] Calculate the initial horizontal displacement y0 of the pile foundation and the initial rotation angle of the pile foundation at the ground according to the engineering monitoring data set {B} The expression is:

[0100]

[0101] Where y0 is the initial horizontal displacement of the pile foundation, is the initial rotation angle of the pile foundation at the ground, F p ′ is the unit horizontal force at the top of the pile foundation, M p ′ is the unit bending moment at the top of the pile foundation, and only the unit horizontal force F acts on the top of the pile foundation p ′ = 1, the horizontal displacement and rotation angle of the pile foundation at the ground are δ y1 and Only unit bending moment M acts on the top of the pile foundation p ′ = 1, the horizontal displacement and rotation angle of the pile foundation at the ground are δ y2 and

[0102] The pile foundation bending moment and pile foundation shear stress are calculated based on the initial horizontal displacement of the pile foundation and the initial rotation angle of the pile foundation at the ground. The expressions are:

[0103]

[0104] Where M(z) is the bending moment of the pile foundation at depth z, Q(z) is the shear stress of the pile foundation at depth z, y0 is the initial horizontal displacement of the pile foundation, α is the deformation coefficient of the pile foundation, E is the elastic modulus of the pile foundation, and I is the moment of inertia of the pile foundation section at depth z. is the initial rotation angle of the pile foundation at the ground, M p is the bending moment at the top of the pile foundation, F p is the horizontal force on the top of the pile foundation, A1, B1, C1, D1 are the coefficients with a dimension of 1 for calculating the bending moment of the pile foundation, and A2, B2, C2, D2 are the coefficients with a dimension of 1 for calculating the shear stress of the pile foundation;

[0105] The pile foundation bending moment, pile foundation shear stress and engineering monitoring data set {B} are combined into the actual engineering data set {C};

[0106] In the actual evaluation, the average values ​​of the bending moment and shear stress of the pile foundation of a 25-story residential community in the south were calculated based on the effective stress of the soil layer, soil layer displacement, pile foundation displacement, pile foundation stress, mutual squeezing force and friction between the pile foundation and soil layer in the engineering monitoring data set {B}: (cover layer: pile foundation bending moment 13kNm, shear stress average 6kPa), (main bearing layer: pile foundation bending moment 56kNm, shear stress average 28kPa), (pile end bearing layer: pile foundation bending moment -25kNm, shear stress average 2kPa). The calculated values ​​of the average bending moment and shear stress of the pile foundation were combined with the engineering monitoring data set {B} to form the actual engineering data set {C}.

[0107] In this embodiment, the method for determining the deviation factor includes:

[0108] Calculate the deviation between the finite element simulation value and the actual measurement value according to the finite element simulation data set {A} and the actual engineering data set {C} to obtain deviation data; the deviation data includes the relative displacement deviation of the pile foundation soil layer, the effective stress deviation of the soil layer, the shear stress deviation of the soil layer, the shear stress deviation of the pile foundation, the bending moment deviation of the pile foundation soil layer, the relative extrusion pressure deviation of the pile foundation soil layer and the friction deviation of the pile foundation soil layer;

[0109] The deviation factor includes a first deviation factor and a second deviation factor;

[0110] The relative displacement deviation of the pile foundation soil layer, the effective stress deviation of the soil layer and the relative extrusion pressure deviation of the pile foundation soil layer are input into the first deviation function to obtain the first deviation factor, which is expressed as:

[0111]

[0112] Where D1 is the first deviation factor, Δy is the relative displacement deviation of the pile foundation soil layer, ΔU is the effective stress deviation of the soil layer, ΔP is the relative extrusion pressure deviation of the pile foundation soil layer, and u Δy is the mean relative displacement deviation of the pile foundation soil layer, u ΔU is the mean deviation of effective stress of soil layer, u ΔP is the mean deviation of relative extrusion pressure of pile foundation soil layer, σ Δy is the standard deviation of the relative displacement of the pile foundation soil layer, σ ΔU is the standard deviation of soil effective stress, σ total is the total standard deviation of all deviations, w1 and w2 are the deviation weight coefficients;

[0113] The soil shear stress deviation, pile foundation shear stress deviation, pile foundation soil relative displacement deviation and pile foundation soil friction deviation are input into the second deviation function to obtain the second deviation factor, which is expressed as:

[0114]

[0115] Where D2 is the second deviation factor, Δf is the friction deviation of the pile foundation soil layer, and uΔf is the mean value of the friction deviation of the pile foundation soil layer, τ s is the soil shear stress deviation, τ p Pile foundation shear stress deviation, w3, w4, w5 are deviation weight coefficients;

[0116] In the actual evaluation, the deviations between the finite element simulation values ​​and the actual measured values ​​were calculated based on the finite element simulation data set {A} and the actual engineering data set {C} to obtain the deviation data of the pile foundation-soil interaction of a 25-story residential area in the south: (cover layer: relative horizontal displacement deviation 0.3mm, relative vertical displacement deviation 2mm, soil layer effective stress deviation 5kPa, soil layer shear stress deviation 0.5kPa, pile foundation bending moment deviation 3kNm, pile foundation shear stress deviation 0.5kPa, pile foundation soil layer relative extrusion pressure deviation 20kPa, pile foundation soil layer friction deviation 10kPa), (main bearing layer: relative horizontal displacement deviation 0mm , relative vertical displacement deviation 0.4mm, soil layer effective stress deviation 20kPa, soil layer shear stress deviation 2kPa, pile foundation bending moment deviation 6kNm, pile foundation shear stress deviation 1kPa, pile foundation soil layer relative extrusion pressure deviation 20kPa, pile foundation soil layer friction deviation 20kPa), (pile end bearing layer: relative horizontal displacement deviation 0mm, relative vertical displacement deviation 0mm, soil layer effective stress deviation 40kPa, soil layer shear stress deviation 2kPa, pile foundation bending moment deviation 5kNm, pile foundation shear stress deviation 1kPa, pile foundation soil layer relative extrusion pressure deviation 50kPa, pile foundation soil layer friction deviation 3kPa)

[0117] According to the above deviation values ​​and deviation functions, the deviation factors of pile foundation-soil interaction in a 25-story residential area in the south were calculated as follows: (first deviation factor: covering layer 2.53, main bearing layer 4, pile end bearing layer 9), (second deviation factor: covering layer 1.13, main bearing layer 2.34, pile end bearing layer 6).

[0118] In this embodiment, the method for determining the comprehensive similarity includes:

[0119] The relative displacement deviation characteristic vector of the pile foundation soil layer is defined as y = [y1, y2, ..., y i ,…,y n ], the characteristic vector of the friction deviation of the pile foundation soil layer is f = [f1,f2,…,f i ,…,f n ], the soil shear stress deviation characteristic vector is τ=[τ1,τ2,…,τ i ,…,τ n ], the characteristic vector of pile foundation bending moment deviation is m = [m1, m2, …, m i ,…,m n ], n is the length of the feature vector;

[0120] The Euclidean distance d between the relative displacement deviation characteristic vector of the pile foundation soil layer and the friction deviation characteristic vector of the pile foundation soil layer is calculated. ed (y,f), the Euclidean distance d between the characteristic vector of soil shear stress deviation and the characteristic vector of pile foundation bending moment deviation ed (τ,m);

[0121] Calculate the first-order difference sequence x of all data diff =[x diff 1,x diff 2,…,x diff i ,…,x diff n-1 ], where x diff i =x diff i+1 -x diff i is the first-order difference value, x∈{y,f,τ,m}, and the dynamic time bending distance d between the relative displacement deviation characteristic vector of the pile foundation soil layer and the friction deviation characteristic vector of the pile foundation soil layer is calculated according to the first-order difference sequence DTW (y diff , f diff ), the dynamic time bending distance d between the characteristic vector of soil shear stress deviation and the characteristic vector of pile foundation bending moment deviation DTW (τ diff , mf diff );

[0122] The comprehensive similarity is calculated based on the Euclidean distance and the dynamic time warping distance. The expression is:

[0123]

[0124] Where S is the comprehensive similarity, a1, b1, a2, b2 are similarity index weight coefficients, which are determined by the entropy weight method;

[0125] In the actual evaluation, a1=0.3, b1=0.2, a2=0.3, b2=0.2. Combining historical data, this set of data is substituted into the above formula to calculate the comprehensive similarity: covering layer 0.93, main bearing layer 0.85, pile end bearing layer 0.89.

[0126] In this embodiment, the method for obtaining the pile foundation soil interaction condition includes:

[0127] A comprehensive feature set is obtained by selecting features of the deviation factor, comprehensive similarity and finite element simulation data set {A}, and the comprehensive feature set is divided into a training set and a test set; the comprehensive feature set includes the deviation factor, comprehensive similarity, relative squeezing force of pile foundation soil layer, friction force of pile foundation soil layer and pile foundation bending moment;

[0128] A pile-soil interaction model is constructed based on physical information neural network, including input layer, hidden layer and output layer;

[0129] The feature data of the training set enters the hidden layer through the input layer for training. The number of input layer features is set to 6. The hidden layer sets multiple fully connected layers and uses the ReLu activation function to assist prediction. The prediction results are output through the output layer with 3 output nodes. The prediction results include the predicted value of the relative squeezing pressure of the pile foundation soil layer, the predicted value of the friction force of the pile foundation soil layer, and the predicted value of the pile foundation bending moment.

[0130] The loss function includes a data fitting term and a physical consistency term. The data fitting term uses the mean square error to evaluate the difference between the predicted value and the true value. The physical consistency term uses the pile foundation soil layer interaction formula and the pile foundation bending moment expression to ensure the physical interpretability of the predicted value. The physical formula includes:

[0131]

[0132] The Adamax optimizer is used to optimize the weights of the pile-foundation soil interaction model, and the test set is used to evaluate the pile-foundation soil interaction model;

[0133] The basic parameter information of the pile foundation soil to be simulated and tested is input into the pile foundation soil interaction model to obtain the pile foundation soil interaction conditions: (cover layer: pile foundation bending moment 14.3kNm, pile foundation soil layer relative extrusion pressure 209kPa, pile foundation soil layer friction 60.5kPa), (main bearing layer: pile foundation bending moment 50.35kNm, pile foundation soil layer relative extrusion pressure 294.5kPa, pile foundation soil layer friction 104.5kPa), (pile end bearing layer: pile foundation bending moment -28.86kNm, pile foundation soil layer relative extrusion pressure 446.25kPa, pile foundation soil layer friction 22.57kPa).

[0134] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A simulation test method for a pile foundation soil interaction model, characterized in that: The following steps are involved: S1. Obtain basic parameter information and engineering monitoring data of pile foundation soil, and pre-process the basic parameter information and the engineering monitoring data; The basic parameter information includes pile foundation parameters and soil parameters; S2, constructing a pile foundation finite element model according to the pile foundation parameters, constructing a soil constraint finite element model according to the soil parameters, and performing a pile foundation soil interaction finite element simulation to obtain a finite element simulation data set {A}; S3, inputting the engineering monitoring data into the pile foundation soil layer interaction formula to obtain an engineering monitoring data set {B}, and obtaining an actual engineering data set {C} according to the engineering monitoring data set {B}; S4, determining a deviation factor according to the finite element simulation data set {A} and the actual engineering data set {C}, and determining a comprehensive similarity according to the actual engineering data set {C}; S5, constructing a pile foundation soil interaction model according to the deviation factor, the comprehensive similarity and the finite element simulation data set {A}, and inputting basic parameter information of the pile foundation soil to be simulated and tested into the pile foundation soil interaction model to obtain the pile foundation soil interaction situation; The method for obtaining the pile foundation soil interaction condition comprises: A comprehensive feature set is obtained by selecting features of the deviation factor, comprehensive similarity and finite element simulation data set {A}, and the comprehensive feature set is divided into a training set and a test set; the comprehensive feature set includes the deviation factor, comprehensive similarity, relative squeezing force of pile foundation soil layer, friction force of pile foundation soil layer and pile foundation bending moment; A pile-soil interaction model is constructed based on physical information neural network, including input layer, hidden layer and output layer; The characteristic data of the training set enters the hidden layer through the input layer for learning. The hidden layer sets multiple fully connected layers and uses the ReLu activation function to assist prediction. The prediction results are output through the output layer. The prediction results include the predicted value of the relative squeezing pressure of the pile foundation soil layer, the predicted value of the friction force of the pile foundation soil layer, and the predicted value of the pile foundation bending moment. The loss function includes a data fitting term and a physical consistency term. The data fitting term uses the mean square error to evaluate the difference between the predicted value and the true value. The physical consistency term uses the pile-soil interaction formula and the pile foundation bending moment expression to ensure the physical interpretability of the predicted value. The Adamax optimizer is used to optimize the weight of the pile-soil interaction model, and the test set is used to evaluate the pile-soil interaction model. The basic parameter information of the pile foundation soil to be simulated and tested is input into the pile foundation soil interaction model to obtain the pile foundation soil interaction situation.

2. The simulation test method of a pile foundation soil interaction model according to claim 1, characterized in that: The method for obtaining the basic parameter information includes: Obtain pile foundation parameters, determine pile foundation dimensions through drawings, calculate pile top loads based on building information, and obtain elastic modulus and Poisson's ratio of pile foundation concrete and steel bars through geotechnical tests; the pile foundation parameters include pile foundation dimensions, pile top loads, elastic modulus and Poisson's ratio of pile foundation concrete and steel bars; Obtain soil parameters, determine the calculation depth and sparse drilling depth based on the length of the pile foundation, perform sparse drilling on the soil layer to determine the soil stratification and take soil samples from different layers; Geotechnical tests are carried out on soil samples of different layers to obtain the density, elastic modulus and Poisson's ratio of the soil layer; the soil parameters include the density, elastic modulus, Poisson's ratio, strength and stratification of the soil layer.

3. The simulation test method of a pile foundation soil interaction model according to claim 1, characterized in that: The method of performing finite element simulation of pile-soil interaction to obtain the finite element simulation data set {A} comprises: The pile-soil interaction model adopts a separated modeling method, and the top of the pile foundation cap is flush with the soil surface; Construct a finite element model of the pile foundation, determine the simulation form of the pile foundation and the cap, determine the cell type and mesh division of concrete and steel bars according to the pile foundation size, determine the constraint conditions of the pile foundation according to the simulation background, and determine the model size and material parameters according to the pile foundation parameters; Construct a soil-constrained finite element model, determine the cell type and mesh division of the soil layer according to the pile foundation size and soil stratification, determine the soil layer constraints according to the simulation background, and determine the model depth and material parameters according to the soil parameters; Determine the contact mode between the pile foundation and the soil, set the contact surface and determine the contact parameters, apply the load according to the pile foundation parameters to perform finite element simulation of the pile foundation-soil interaction to obtain a finite element simulation data set {A}; The finite element simulation data set {A} includes soil layer stress distribution, soil layer displacement, pile foundation stress distribution, pile foundation displacement, pile foundation bending moment and pile foundation-soil interaction force; the pile foundation-soil interaction force includes pile foundation soil layer relative extrusion force and pile foundation soil layer friction force.

4. The simulation test method of a pile foundation soil interaction model according to claim 1, characterized in that: The method of inputting the engineering monitoring data into the pile foundation soil layer interaction formula to obtain the engineering monitoring data set {B} comprises: Acquiring engineering monitoring data through strain gauges, pressure sensors and laser rangefinders; the engineering monitoring data includes soil layer stress distribution, soil layer displacement, pile foundation compressive stress distribution and pile foundation displacement; The pile foundation-soil layer interaction formula includes an expression for the relative squeezing force of the pile foundation-soil layer and an expression for the friction force of the pile foundation-soil layer; The relative squeezing pressure of the pile foundation soil layer is calculated based on the engineering monitoring data. The relative squeezing pressure of the pile foundation soil layer is expressed as: Where P(x,y) is the relative squeezing pressure of the soil layer inside the pile foundation per unit area, z is the depth below the surface, x and y are horizontal positions, k(z) is the foundation coefficient, and n is an exponent. k(z) and n vary with z. is the horizontal displacement of the pile foundation p Horizontal displacement of soil layer s The difference between the pile foundation and the soil layer is E sr is the elastic modulus of the reference soil layer, E s is the elastic modulus of the soil layer, [I] is the influence coefficient matrix, σ s is the soil stress around the pile foundation; The friction force of the pile foundation soil layer is calculated based on the engineering monitoring data. The friction force of the pile foundation soil layer is expressed as: Where f(z) is the friction force of the inner pile foundation soil layer at depth z, P is the relative extrusion pressure per unit area of ​​the inner pile foundation soil layer, θ is the basic friction angle, is the roughness coefficient of the soil layer, τ s is the peak shear strength of the soil layer, and JCS is the compressive strength of the soil layer; The engineering monitoring data, the relative squeezing force of the pile foundation soil layer and the friction force of the pile foundation soil layer form the engineering monitoring data set {B}.

5. The simulation test method of a pile foundation soil interaction model according to claim 1, characterized in that: The method for obtaining the actual engineering data set {C} according to the engineering monitoring data set {B} comprises: Calculate the initial horizontal displacement y0 of the pile foundation and the initial rotation angle of the pile foundation at the ground according to the engineering monitoring data set {B} The expression is: Where y0 is the initial horizontal displacement of the pile foundation, is the initial rotation angle of the pile foundation at the ground, F' p is the unit horizontal force at the top of the pile foundation, M' p is the unit bending moment at the top of the pile foundation, and only unit horizontal force F' acts on the top of the pile foundation p = 1, the horizontal displacement and rotation angle of the pile foundation at the ground are δ y1 and Only unit bending moment M' acts on the top of the pile foundation p = 1, the horizontal displacement and rotation angle of the pile foundation at the ground are δ y2 and The pile foundation bending moment and pile foundation shear stress are calculated based on the initial horizontal displacement of the pile foundation and the initial rotation angle of the pile foundation at the ground. The expressions are: Where M(z) is the bending moment of the pile foundation at depth z, Q(z) is the shear stress of the pile foundation at depth z, y0 is the initial horizontal displacement of the pile foundation, α is the deformation coefficient of the pile foundation, e is the elastic modulus of the pile foundation, and I is the moment of inertia of the pile foundation section at depth z. is the initial rotation angle of the pile foundation at the ground, M p is the bending moment at the top of the pile foundation, F p is the horizontal force on the top of the pile foundation, A1, B1, C1, D1 are the coefficients with a dimension of 1 for calculating the bending moment of the pile foundation, and A2, B2, C2, D2 are the coefficients with a dimension of 1 for calculating the shear stress of the pile foundation; The pile foundation bending moment, pile foundation shear stress and engineering monitoring data set {B} are combined into the actual engineering data set {C}.

6. The simulation test method of a pile foundation soil interaction model according to claim 1, characterized in that: The method for determining the deviation factor comprises: Calculate the deviation between the finite element simulation value and the actual measurement value according to the finite element simulation data set {A} and the actual engineering data set {C} to obtain deviation data; the deviation data includes the relative displacement deviation of the pile foundation soil layer, the effective stress deviation of the soil layer, the shear stress deviation of the soil layer, the shear stress deviation of the pile foundation, the bending moment deviation of the pile foundation soil layer, the relative extrusion pressure deviation of the pile foundation soil layer and the friction deviation of the pile foundation soil layer; The deviation factor includes a first deviation factor and a second deviation factor; The relative displacement deviation of the pile foundation soil layer, the effective stress deviation of the soil layer and the relative extrusion pressure deviation of the pile foundation soil layer are input into the first deviation function to obtain the first deviation factor, which is expressed as: Where D1 is the first deviation factor, Δy is the relative displacement deviation of the pile foundation soil layer, ΔU is the effective stress deviation of the soil layer, ΔP is the relative extrusion pressure deviation of the pile foundation soil layer, and u Δy is the mean relative displacement deviation of the pile foundation soil layer, u ΔU is the mean deviation of effective stress of soil layer, u ΔP is the mean deviation of relative extrusion pressure of pile foundation soil layer, σ Δy is the standard deviation of the relative displacement of the pile foundation soil layer, σ ΔU is the standard deviation of soil effective stress, σ total is the total standard deviation of all deviations, w1 and w2 are the deviation weight coefficients; The soil shear stress deviation, pile foundation shear stress deviation, pile foundation soil relative displacement deviation and pile foundation soil friction deviation are input into the second deviation function to obtain the second deviation factor, which is expressed as: Where D2 is the second deviation factor, Δf is the friction deviation of the pile foundation soil layer, and u Δf is the mean value of the friction deviation of the pile foundation soil layer, Δτ s is the shear stress deviation of the soil layer, Δτ p Pile foundation shear stress deviation, w3, w4, w5 are deviation weight coefficients.

7. The simulation test method of a pile foundation soil interaction model according to claim 1, characterized in that: The method for determining the comprehensive similarity comprises: The relative displacement deviation characteristic vector of the pile foundation soil layer is defined as y = [y1, y2, …, y i ,…,y n ], the characteristic vector of the friction deviation of the pile foundation soil layer is f = [f1,f2,…,f i ,…,f n ], the soil shear stress deviation characteristic vector is τ=[τ1,τ2,…,τ i ,…,τ n ], the characteristic vector of pile foundation bending moment deviation is m = [m1, m2, …, m i ,…,m n ], n is the length of the feature vector; The Euclidean distance d between the relative displacement deviation characteristic vector of the pile foundation soil layer and the friction deviation characteristic vector of the pile foundation soil layer is calculated. ed (y,f), the Euclidean distance d between the characteristic vector of soil shear stress deviation and the characteristic vector of pile foundation bending moment deviation ed (τ,m); Calculate the first-order difference sequence x of all data diff =[x diff1 ,x diff2 ,…,x diffi ,…,x diffn-1 ], where x diffi =x diffi+1 -x diffi is the first-order difference value, x∈{y,f,τ,m}, and the dynamic time bending distance d between the relative displacement deviation characteristic vector of the pile foundation soil layer and the friction deviation characteristic vector of the pile foundation soil layer is calculated according to the first-order difference sequence DTW (y diff , f diff ), the dynamic time bending distance d between the characteristic vector of soil shear stress deviation and the characteristic vector of pile foundation bending moment deviation DTW (τ diff , mf diff ); The comprehensive similarity is calculated based on the Euclidean distance and the dynamic time warping distance. The expression is: Among them, S is the comprehensive similarity, a1, b1, a2, and b2 are the weight coefficients of similarity indicators, which are determined by the entropy weight method.

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