A method and system for evaluating the soil squeezing effect of static pressure precast pipe piles for transmission towers

Abstract

The present invention discloses a method and system for evaluating the soil compaction effect of static precast pipe piles for transmission towers, which relates to the technical field of soil compaction effect evaluation and includes the following steps: obtaining geological exploration data of the construction area, establishing a three-dimensional geological model, dividing soil units and assigning non-linear constitutive relations; based on the three-dimensional geological model, obtaining the stress propagation path and soil compaction range around the pile, and identifying stress concentration areas and local liquefaction risk areas; analyzing the risk characteristics of sudden changes in soil compaction effect at the junction of hard interlayers and soft lens bodies according to the stress concentration areas and local liquefaction risk areas; combining the risk characteristics of sudden changes in soil compaction effect with real-time pile driving resistance data to correct the soil compaction range and generate a construction risk warning map. The present invention not only provides risk prediction of soil compaction effect, but also dynamically corrects the risk by combining real-time construction data, generating an intuitive construction risk warning map, which helps construction personnel to timely discover and respond to potential risks and ensure the smooth progress of construction.

Description

Technical Field

[0001] The present invention relates to the technical field of soil squeezing effect evaluation, and more specifically, to a method and system for evaluating the soil squeezing effect of statically pressed prefabricated pipe piles of a power transmission tower. Background Art

[0002] In the transmission tower foundation project, static prefabricated pipe piles are widely used due to their advantages such as low construction noise, high bearing capacity and controllable construction period. However, the displacement field and stress field changes caused by the squeezing of the soil during the static pressure of the pipe piles (i.e., the soil squeezing effect) may lead to engineering problems such as surface uplift, deformation of adjacent pipelines, and tilting of buildings. Especially in sensitive strata such as soft soil and sandy soil, the accurate evaluation and control of the soil squeezing effect has become a key technical difficulty to ensure the safe construction of transmission lines.

[0003] For example, the invention patent with announcement number CN119026403A discloses a method, medium and system for evaluating the impact of soil squeezing effect of pile sinking on pile foundation load, which belongs to the technical field of soil squeezing effect of pile sinking, including: installing multiple vibration sensors and strain sensors at different depths and distances around the pile foundation, continuously collecting vibration signals and strain signals, and forming a vibration-strain signal group. After preprocessing and alignment, the time-frequency analysis method is used to determine the optimal time window length and extract the time-frequency characteristics of each signal. Based on the established dynamic equation group, multiple analytical solutions describing the vibration propagation, stress distribution, deformation characteristics and pile-soil interaction of the soil around the pile foundation are solved. These analytical solutions and the feature group to be measured are used as input parameters to establish a mathematical model of soil squeezing effect of pile sinking, calculate the stress-strain state of the soil around the pile, and then evaluate the impact of soil squeezing effect on the bearing capacity of the pile foundation. Finally, based on the evaluation results, the bearing capacity change index of the pile foundation is calculated to determine the degree of influence of soil squeezing effect on the pile foundation load.

[0004] For example, the invention patent with announcement number CN117972992A announces a method for constructing a numerical model for the soil squeezing effect of static pressure pile driving, which includes the following steps: Step 1: Establishing a physical model, using a loading system to perform static pressure construction according to design conditions, recording the data of the pressure box, strain gauge and displacement meter, and analyzing to obtain the pile body axial force, pile side friction resistance and soil pressure; Step 2: Constructing and simulating a numerical model to obtain data related to the shear characteristics of the soil, including the pile body axial force, pile side friction resistance and soil pressure data; Step 3: Comparing and analyzing the physical model experimental results with the numerical model results. If the comparison results show a match, the obtained numerical model is a reliable numerical model. This solution is used to solve the problem that the reliability of the existing technology that only uses numerical models for simulation analysis to optimize pipe pile design and predict the pile driving process is difficult to ensure.

[0005] In the above - disclosed technical solutions, there are at least the following technical problems: When the existing technology encounters complex geology such as hard - soft interlayers, boulders or lenses, it is difficult to predict the stress propagation path and the soil extrusion range of the soil mass. The hard interlayer may cause stress concentration, while the soft lens is prone to local liquefaction, and the existing models cannot accurately quantify such mutation risks. In view of the above problems, the present invention proposes a solution. Summary of the Invention

[0006] In order to overcome the above - mentioned defects of the prior art, an embodiment of the present invention provides a method and system for evaluating the soil - extrusion effect of static - pressure precast pipe piles for transmission towers. By identifying the stress - concentration area and the local liquefaction risk area, and analyzing the mutation risk characteristics of the soil - extrusion effect at the junction of the hard interlayer and the soft lens, it solves the problem that the mutation risk of the soil - extrusion effect at the junction of the hard interlayer and the soft lens cannot be quantified.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for evaluating the soil - extrusion effect of static - pressure precast pipe piles for transmission towers, comprising the following steps: obtaining geological exploration data of the construction area, establishing a three - dimensional geological model, dividing soil units and assigning non - linear constitutive relations; based on the three - dimensional geological model and the non - linear constitutive relations, obtaining the stress propagation path and the soil - extrusion range of the soil around the pile, and identifying the stress - concentration area and the local liquefaction risk area; analyzing the mutation risk characteristics of the soil - extrusion effect at the junction of the hard interlayer and the soft lens according to the stress - concentration area and the local liquefaction risk area; combining the mutation risk characteristics of the soil - extrusion effect with the real - time pile - driving resistance data to correct the soil - extrusion range and generate a construction risk warning map.

[0009] In a preferred embodiment, the obtaining geological exploration data of the construction area, establishing a three - dimensional geological model, dividing soil units and assigning non - linear constitutive relations is specifically: obtaining geological exploration data of the construction area and establishing a three - dimensional geological model of the construction area; dividing the soil in the three - dimensional geological model into several small soil units according to the distribution and characteristics of the soil layers; obtaining the parameters of the non - linear constitutive model according to the geological exploration data and assigning the non - linear constitutive model to each soil unit.

[0010] In a preferred embodiment, the obtaining the stress propagation path and the soil - extrusion range of the soil around the pile based on the three - dimensional geological model and the non - linear constitutive relations is specifically: setting the quasi - static loading conditions and contact interface parameters for pile penetration based on the three - dimensional geological model; performing elastoplastic analysis on the soil units through the non - linear constitutive relations based on the quasi - static loading conditions and contact interface parameters to obtain the stress field, strain field and displacement field distributions of the soil around the pile; generating a three - dimensional principal stress propagation path by streamline integration based on the stress field and strain field, and determining the boundary threshold of the soil - extrusion range through the gradient change of the displacement nephogram.

[0011] In a preferred embodiment, based on the stress field and strain field, a three-dimensional principal stress propagation path is generated by streamline integration method, and the boundary threshold of the soil extrusion range is determined by the gradient change of the displacement contour. Specifically: based on the principal stress direction field, a stress network radiating outward from the pile surface is constructed to generate the stress propagation path; the radial displacement contour is obtained according to the displacement field distribution, and the displacement gradient is calculated; when the gradient value drops to the preset gradient threshold, it is determined as the boundary threshold of the soil extrusion range.

[0012] In a preferred embodiment, the identification of the stress concentration area is specifically as follows: based on the principle of virtual work, a finite element equation is constructed, and the stress tensor data of each soil element in the construction area is obtained according to the finite element analysis result; several principal stresses are obtained according to the characteristic equation corresponding to the stress tensor data; the maximum principal stress among several principal stresses is obtained, and the ratio of the maximum principal stress to the average initial stress in the construction area is used as the stress concentration coefficient; the stress concentration coefficients of all soil elements in the construction area are calculated, and when the stress concentration coefficient of a soil element exceeds the preset threshold, the soil element is marked as part of the stress concentration area.

[0013] In a preferred embodiment, the analysis of the mutation risk characteristics of the soil extrusion effect at the junction of the hard interlayer and the soft lens body according to the stress concentration area and the local liquefaction risk area is specifically as follows: the geometric characteristics and mechanical parameters of the interface between the hard interlayer and the soft lens body are extracted through a three-dimensional geological model to obtain the stiffness difference ratio, strength difference ratio and interface dip angle between the hard interlayer and the soft lens body; based on the pre-obtained shear stress mutation gradient and pore water pressure dynamic change rate on both sides of the interface, the stress mutation component and the liquefaction-induced component are respectively calculated; combined with the geometric relationship between the interface dip angle, thickness and pile diameter, the geometric sensitivity component is calculated; the stress mutation component, liquefaction-induced component and geometric sensitivity component are fused by weighted product, and combined with the stiffness difference ratio and strength difference ratio, the mutation risk characteristics of the soil extrusion effect are generated.

[0014] In a preferred embodiment, the mutation risk characteristics of the soil extrusion effect are combined with the real-time pile driving resistance data to correct the soil extrusion range and generate a construction risk warning map. Specifically: the tip resistance, side friction resistance and penetration rate during pile driving are obtained in real time, and the ratio of the real-time resistance to the theoretical resistance is calculated as the dynamic correction factor; the mutation risk characteristics of the soil extrusion effect are scaled according to the dynamic correction factor to update the risk level at the junction of the hard interlayer and the soft lens body; based on the updated mutation risk characteristics of the soil extrusion effect, the boundary radius and depth of the soil extrusion range in the three-dimensional geological model are adjusted by the radial basis function interpolation method; in the three-dimensional geological model, the soil extrusion range, stress concentration area, liquefaction risk area and the updated risk level are mapped into a multi-color scale warning map; when the high-risk area in the warning map overlaps with the preset trajectory of the pile body, an audible and visual alarm signal is triggered and the avoidance recommended coordinates are output.

[0015] Technical effects and advantages of an evaluation method and system for the soil squeezing effect of static pressure precast pipe piles of transmission towers according to the present invention:

[0016] 1. By integrating a multi-factor coupling model of the stiffness difference, shear stress mutation gradient, and pore water pressure dynamic response at the interface between hard interlayers and soft lenses, and dynamically correcting it in combination with real-time pile driving resistance data, the present invention realizes the accurate calculation of the risk characteristics of sudden changes in the soil squeezing effect, and effectively identifies the stress mutation and liquefaction chain risk of the "hard-soft interface" that are difficult to capture by traditional methods.

[0017] 2. By obtaining detailed geological exploration data, establishing a three-dimensional geological model, and combining with non-linear constitutive relations, the present invention can accurately simulate the stress-strain relationship of the soil during the stress application process. This helps to accurately predict the stress propagation path, soil squeezing range of the soil around the pile, and identify stress concentration areas and local liquefaction risk areas, providing a scientific basis for construction.

[0018] 3. The present invention not only provides risk prediction of the soil squeezing effect, but also dynamically corrects the risk in combination with real-time construction data, generating an intuitive construction risk warning map. This helps construction personnel to timely discover and respond to potential risks, ensuring the safety and smooth progress of construction. Brief Description of the Drawings

[0019] Figure 1 It is a schematic flow chart of an evaluation method for the soil squeezing effect of static pressure precast pipe piles of transmission towers according to the present invention;

[0020] Figure 2 It is a schematic structural diagram of an evaluation system for the soil squeezing effect of static pressure precast pipe piles of transmission towers according to the present invention. Detailed Embodiments

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] Embodiment 1, Figure 1 An evaluation method for the soil squeezing effect of static pressure precast pipe piles of transmission towers according to the present invention is given, including the following steps:

[0023] S1. Obtain geological exploration data of the construction area, establish a three-dimensional geological model, divide soil units and assign non-linear constitutive relations;

[0024] The geological exploration data includes soil parameters, interlayer distribution, boulder position, and lens shape;

[0025] Obtain the geological exploration data of the construction area, establish a three-dimensional geological model, divide the soil body into units, and assign a non-linear constitutive relationship, specifically as follows:

[0026] Obtain the geological exploration data of the construction area, and establish a three-dimensional geological model of the construction area based on finite element analysis;

[0027] Divide the soil body in the three-dimensional geological model into several small soil body units according to the distribution and characteristics of the soil layers. Each unit has uniform soil properties and physical and mechanical properties;

[0028] Obtain the parameters of the non-linear constitutive model according to the geological exploration data, and assign the non-linear constitutive model to each soil body unit.

[0029] The non-linear constitutive model is used to describe the stress-strain relationship of the soil body during the stress process. The non-linear constitutive model includes the Mohr-Coulomb model, the Duncan-Chang model, and the Cambridge model;

[0030] Mohr-Coulomb model: It is applicable to simulating various soil body materials such as sandy soil and clay. It considers the relationship between the shear strength of the soil body and the normal stress, and describes the mechanical properties of the soil body through parameters such as cohesion and internal friction angle, and can better reflect the elastoplastic behavior of the soil body.

[0031] Duncan-Chang model: It is established based on the generalized Hooke's law and the Mohr-Coulomb strength criterion, can consider the non-linear elastic characteristics and dilatancy of the soil body, and is applicable to simulating the deformation of the soil body under general stress levels.

[0032] Cambridge model: It considers factors such as elastoplastic coupling, dilatancy, and stress history of the soil body, and can more accurately describe the mechanical behavior of clay under complex stress states.

[0033] S2. Based on the three-dimensional geological model and the non-linear constitutive relationship, obtain the stress propagation path and soil compaction range around the pile, and identify the stress concentration area and local liquefaction risk area;

[0034] The specific method for obtaining the stress propagation path and soil compaction range around the pile based on the three-dimensional geological model and the non-linear constitutive relationship is as follows:

[0035] Set the quasi-static loading conditions and contact interface parameters for the pile penetration based on the three-dimensional geological model;

[0036] Conduct elastoplastic analysis on the soil body units through the non-linear constitutive relationship based on the quasi-static loading conditions and contact interface parameters to obtain the stress field, strain field, and displacement field distributions of the soil around the pile;

[0037] Based on the stress field and strain field, a three-dimensional principal stress propagation path is generated by the streamline integration method, and the boundary threshold of the soil extrusion range is determined by the gradient change of the displacement contour map.

[0038] Contact interface parameters: Set the friction coefficient and tangential stiffness of the pile-soil interface, and use the penalty function method to simulate the interface slip behavior.

[0039] Quasi-static loading conditions: Define the quasi-static loading conditions for pile penetration (such as the displacement control rate of 0.01 - 0.1 m / s), and apply the load in stages to simulate the pile driving process.

[0040] The method of generating a three-dimensional principal stress propagation path based on the stress field and strain field by the streamline integration method and determining the boundary threshold of the soil extrusion range by the gradient change of the displacement contour map is specifically as follows:

[0041] Based on the principal stress direction field, construct a stress network radiating outward from the pile surface to generate a stress propagation path;

[0042] Obtain the radial displacement contour map according to the displacement field distribution and calculate the displacement gradient;

[0043] When the gradient value drops to the preset gradient threshold, it is determined as the boundary threshold of the soil extrusion range.

[0044] The method of identifying the stress concentration area is specifically as follows:

[0045] Based on the principle of virtual work, construct a finite element equation, and obtain the stress tensor data of each soil element in the construction area according to the finite element analysis results;

[0046] According to the characteristic equation corresponding to the stress tensor data, obtain several principal stresses;

[0047] Obtain the maximum principal stress among several principal stresses, and use the ratio of the maximum principal stress to the average initial stress in the construction area as the stress concentration coefficient;

[0048] Calculate the stress concentration coefficients of all soil elements in the construction area. When the stress concentration coefficient of a soil element exceeds the preset threshold, mark the soil element as part of the stress concentration area.

[0049] The characteristic equation corresponding to the stress tensor data is specifically as follows:

[0050]

[0051] Among them, is the stress component in the j direction on the i direction plane, is the eigenvalue, is the Kronecker symbol.

[0052] The stress concentration coefficient is specifically as follows:

[0053]

[0054] wherein, is the stress concentration factor, is the maximum principal stress, is the number of soil elements in the construction area, is the stress value of the i-th soil element.

[0055] The local liquefaction risk area is specifically:

[0056] Obtain the pore water pressure and effective stress data of each soil element in the construction area based on the finite element simulation results;

[0057] Take the ratio of the pore water pressure increment to the initial effective vertical stress as the pore pressure ratio;

[0058] Calculate the pore pressure ratio of each saturated soil element for judgment. If the pore pressure ratio exceeds the set risk threshold, mark the soil element as part of the local liquefaction risk area.

[0059] The pore pressure ratio is specifically:

[0060]

[0061]

[0062] wherein, is the pore water pressure increment, is the stress component in the j direction on the i-th plane, is the effective stress data in the j direction on the i-th plane, is the Kronecker symbol, is the pore pressure ratio, is the depth of the soil element from the ground surface, is the effective unit weight of the soil element.

[0063] S3. Analyze the risk characteristics of the sudden change of soil squeezing effect at the junction of the hard interlayer and the soft lens body according to the stress concentration area and the local liquefaction risk area;

[0064] The analysis of the risk characteristics of the sudden change of soil squeezing effect at the junction of the hard interlayer and the soft lens body according to the stress concentration area and the local liquefaction risk area is specifically:

[0065] Extract the geometric characteristics and mechanical parameters of the interface between the hard interlayer and the soft lens body through a three-dimensional geological model to obtain the stiffness difference ratio, strength difference ratio and interface dip angle between the hard interlayer and the soft lens body;

[0066] Based on the pre-acquired shear stress mutation gradient and pore water pressure dynamic change rate on both sides of the interface, calculate the stress mutation component and liquefaction-induced component respectively;

[0067] Combined with the geometric relationship between the interface dip angle, thickness and pile diameter, calculate the geometric sensitivity component;

[0068] Fuse the stress mutation component, liquefaction-induced component and geometric sensitivity component through a weighted product model, and combine the stiffness difference ratio and strength difference ratio to generate the sudden change risk characteristics of the soil compaction effect.

[0069] The stress mutation component and liquefaction-induced component are specifically:

[0070]

[0071]

[0072] Among them, is the stress mutation component, and are the shear stress distributions on both sides of the interface respectively, is the liquefaction-induced component, is the pore water pressure increment, is the initial effective stress, is the time change amount, is the initial time.

[0073] The geometric sensitivity component is specifically:

[0074]

[0075] Among them, is the geometric sensitivity component, is the interface dip angle, is the interface thickness, is the diameter of the pipe pile.

[0076] The sudden change risk characteristics of the soil compaction effect are specifically:

[0077]

[0078] Among them, is the sudden change risk characteristics of the soil compaction effect, is the stress mutation component, is the liquefaction-induced component, is the geometric sensitivity component, and are the preset weight coefficients respectively, is the elastic modulus of the hard interlayer, is the elastic modulus of the soft lens body, and are the cohesion of the hard interlayer and the soft lens respectively, and are the internal friction angles of the hard interlayer and the soft lens respectively.

[0079] S4. Combine the risk characteristics of the sudden change of the soil squeezing effect with the real-time pile driving resistance data to correct the soil squeezing range and generate a construction risk warning map.

[0080] The combination of the risk characteristics of the sudden change of the soil squeezing effect with the real-time pile driving resistance data to correct the soil squeezing range and generate a construction risk warning map is specifically as follows:

[0081] Obtain the pile tip resistance, side friction resistance and penetration rate during the pile driving process in real time, and calculate the ratio of the real-time resistance to the theoretical resistance as the dynamic correction factor; scale the risk characteristics of the sudden change of the soil squeezing effect according to the dynamic correction factor to update the risk level at the junction of the hard interlayer and the soft lens; based on the updated risk characteristics of the sudden change of the soil squeezing effect, adjust the boundary radius and depth of the soil squeezing range in the three-dimensional geological model by the radial basis function interpolation method; map the soil squeezing range, stress concentration area, liquefaction risk area and the updated risk level in the three-dimensional geological model into a multi-color scale warning map, where the high-risk area is marked with a red isosurface, and the medium-low risk area is shown as a yellow-green gradient; when the high-risk area in the warning map overlaps with the preset trajectory of the pile body, trigger an audible and visual alarm signal and output the avoidance suggestion coordinates.

[0082] The dynamic correction factor is specifically:

[0083]

[0084]

[0085] where is the dynamic correction factor, is the real-time resistance, is the theoretical resistance, is the total frictional force on the pile side, is the total frictional force at the pile tip.

[0086] The adjustment of the boundary radius and depth of the soil squeezing range in the three-dimensional geological model is specifically:

[0087]

[0088]

[0089]

[0090] where is the updated risk characteristics of the sudden change of the soil squeezing effect, is the dynamic correction factor, is the risk characteristic of the sudden change of soil compaction effect is the boundary radius of the original soil compaction range is the diameter of the pipe pile is the elastic modulus is the cohesion is the internal friction angle is the boundary radius of the updated soil compaction range

[0091] When the high-risk area in the early warning map overlaps with the preset trajectory of the pile body, an audible and visual alarm signal is triggered and the avoidance recommended coordinates are output. Specifically:

[0092] Calculate the minimum distance between the high-risk equipotential surface and the designed axis of the pile body. If it is less than half of the diameter of the pipe pile, it is determined that there is a trajectory conflict, and the offset direction and distance are output.

[0093] Embodiment 2, a static pressure precast pipe pile soil compaction effect evaluation system for transmission towers, includes the following modules:

[0094] Geological data acquisition module: used to acquire geological exploration data of the construction area, establish a three-dimensional geological model, divide soil units and assign non-linear constitutive relations;

[0095] Risk area identification module: used to obtain the stress propagation path and soil compaction range around the pile based on the three-dimensional geological model and non-linear constitutive relations, and identify stress concentration areas and local liquefaction risk areas;

[0096] Soil compaction effect sudden change risk calculation module: used to analyze the risk characteristics of the sudden change of soil compaction effect at the junction of hard interlayers and soft lenses based on stress concentration areas and local liquefaction risk areas;

[0097] Soil compaction range correction and early warning module: used to correct the soil compaction range by combining the risk characteristics of the sudden change of soil compaction effect with real-time pile driving resistance data, and generate a construction risk early warning map.

[0098] The above formulas are all dimensionless and take their numerical values for calculation. The formulas are obtained by collecting a large amount of data for software simulation to get a formula closest to the real situation. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0099] The above embodiments can be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product.

[0100] Those of ordinary skill in the art can realize that the modules and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0101] In addition, the functional modules in each embodiment of the present invention can be integrated into one processing module, or each module can exist physically alone, or two or more modules can be integrated into one module.

[0102] As mentioned above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

[0103] Finally: The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for evaluating the soil squeezing effect of statically pressed prefabricated pipe piles of power transmission towers, characterized in that: The following steps are involved: Obtain geological exploration data of the construction area, establish a three-dimensional geological model, divide the soil units and assign nonlinear constitutive relationships; Based on the three-dimensional geological model and nonlinear constitutive relationship, the stress propagation path and soil extrusion range of the soil around the pile are obtained, and the stress concentration area and local liquefaction risk area are identified; The stress propagation path and soil extrusion range of the soil around the pile are obtained as follows: Set the quasi-static loading conditions and contact interface parameters for pile penetration based on the 3D geological model; Based on the quasi-static loading conditions and contact interface parameters, the soil unit is subjected to elastic-plastic analysis through nonlinear constitutive relations, and the stress field, strain field and displacement field distribution of the soil around the pile are obtained. Based on the stress field and strain field, the three-dimensional principal stress propagation path is generated by the streamline integration method, and the boundary threshold of the soil squeezing range is determined by the gradient change of the displacement cloud map. According to the stress concentration area and local liquefaction risk area, the sudden change risk characteristics of soil squeezing effect at the junction of hard interlayer and soft lens are analyzed; The sudden change risk characteristics of soil squeezing effect are combined with real-time pile driving resistance data to correct the soil squeezing range and generate a construction risk warning map.

2. The method for evaluating soil squeezing effect of statically pressed prefabricated pipe piles of power transmission towers according to claim 1 is characterized in that: The geological exploration data of the construction area is obtained, a three-dimensional geological model is established, soil units are divided and nonlinear constitutive relations are given, specifically: Obtain geological exploration data of the construction area and establish a three-dimensional geological model of the construction area; The soil in the three-dimensional geological model is divided into several small soil units according to the distribution and characteristics of the soil layers; The parameters of the nonlinear constitutive model are obtained according to the geological exploration data, and a nonlinear constitutive model is assigned to each soil unit.

3. The method for evaluating soil squeezing effect of statically pressed prefabricated pipe piles of power transmission towers according to claim 2 is characterized in that: Based on the stress field and strain field, the three-dimensional principal stress propagation path is generated by the streamline integration method, and the boundary threshold of the soil squeezing range is determined by the gradient change of the displacement cloud map, specifically: Based on the principal stress direction field, a stress network radiating outward from the pile surface is constructed to generate the stress propagation path; Obtain radial displacement cloud map according to the displacement field distribution and calculate the displacement gradient; When the gradient value drops to the preset gradient threshold, it is determined as the boundary threshold of the soil squeezing range.

4. The method for evaluating soil squeezing effect of statically pressed prefabricated pipe piles of power transmission towers according to claim 3 is characterized in that: The identification of stress concentration areas is specifically: Finite element equations are constructed based on the principle of virtual work, and stress tensor data of each soil unit in the construction area are obtained according to the finite element analysis results; According to the characteristic equation corresponding to the stress tensor data, several principal stresses are obtained; Obtain the maximum principal stress among several principal stresses, and take the ratio of the maximum principal stress to the average initial stress in the construction area as the stress concentration factor; The stress concentration factor of all soil elements in the construction area is calculated, and when the stress concentration factor of a soil element exceeds a preset threshold, the soil element is marked as part of the stress concentration area.

5. The method for evaluating soil squeezing effect of statically pressed prefabricated pipe piles of power transmission towers according to claim 4 is characterized in that: The sudden change risk characteristics of the soil squeezing effect at the junction of the hard interlayer and the soft lens are analyzed based on the stress concentration area and the local liquefaction risk area, specifically: The geometric characteristics and mechanical parameters of the interface between the hard interlayer and the soft lens are extracted through the three-dimensional geological model, and the stiffness difference ratio, strength difference ratio and interface inclination angle of the hard interlayer and the soft lens are obtained. Based on the pre-obtained shear stress mutation gradient on both sides of the interface and the dynamic change rate of pore water pressure, the stress mutation component and the liquefaction induced component are calculated respectively; Combining the geometric relationship between the interface inclination angle and thickness and the pile diameter, the geometric sensitive component is calculated; The stress mutation component, liquefaction induced component and geometric sensitive component are fused by weighted product, and combined with the stiffness difference ratio and strength difference ratio to generate the soil squeezing effect mutation risk characteristics.

6. The method for evaluating soil squeezing effect of statically pressed prefabricated pipe piles of power transmission towers according to claim 5 is characterized in that: The sudden change risk characteristics of soil squeezing effect are combined with real-time pile driving resistance data to correct the soil squeezing range and generate a construction risk warning map, specifically: Obtain the pile end resistance, side friction resistance and penetration rate in real time during pile sinking, and calculate the ratio of real-time resistance to theoretical resistance as a dynamic correction factor; Scaling the sudden change risk characteristics of the soil squeezing effect according to the dynamic correction factor to update the risk level at the interface between the hard interlayer and the soft weak lens; Based on the updated risk characteristics of soil squeezing effect mutation, the boundary radius and depth of the soil squeezing range in the 3D geological model are adjusted by radial basis function interpolation method. In the three-dimensional geological model, the soil extrusion range, stress concentration area, liquefaction risk area and updated risk level are mapped into a multi-color warning map; When the high-risk area in the early warning map overlaps with the preset trajectory of the pile, an audible and visual alarm signal is triggered and the avoidance suggestion coordinates are output.

7. The method for evaluating soil squeezing effect of statically pressed prefabricated pipe piles of power transmission towers according to claim 6 is characterized in that: The stress concentration factor is specifically: in, is the stress concentration factor, is the maximum principal stress, is the number of soil units in the construction area, is the stress value of the ith soil element.

8. The method for evaluating soil squeezing effect of statically pressed prefabricated pipe piles of power transmission towers according to claim 7 is characterized in that: The adjustment of the boundary radius and depth of the soil squeezing range in the three-dimensional geological model is specifically as follows: in, is the updated risk characteristic of soil squeezing effect mutation. is the dynamic correction factor, is the risk characteristic of sudden change of soil squeezing effect. is the boundary radius of the original soil extrusion range, is the diameter of the pile, is the elastic modulus, For cohesion, is the internal friction angle, It is the boundary radius of the updated soil extrusion range.

9. A system using the method for evaluating soil squeezing effect of statically pressed prefabricated pipe piles of a power transmission tower as claimed in any one of claims 1 to 8, characterized in that: Includes the following modules: Geological data acquisition module: used to obtain geological exploration data of the construction area, establish a three-dimensional geological model, divide soil units and assign nonlinear constitutive relationships; Risk area identification module: used to obtain the stress propagation path and soil extrusion range of the soil around the pile based on the three-dimensional geological model and nonlinear constitutive relationship, and identify stress concentration areas and local liquefaction risk areas; Soil squeezing effect mutation risk calculation module: used to analyze the soil squeezing effect mutation risk characteristics at the junction of the hard interlayer and the soft lens according to the stress concentration area and the local liquefaction risk area; Soil squeezing range correction and early warning module: It is used to correct the soil squeezing range by combining the sudden change risk characteristics of soil squeezing effect with real-time pile driving resistance data to generate a construction risk early warning map.

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