Landslide disaster risk evaluation method and system based on power transmission tower failure model

Abstract

The invention relates to the technical field of disaster risk evaluation research, in particular to a landslide disaster risk evaluation method and system based on a power transmission tower failure model. The method comprises the following steps: carrying out detailed investigation on a landslide area to obtain a deformation relationship between a power transmission tower and the earth surface; fLAC3D and ANSYS numerical simulation software is utilized to obtain a deformation failure model and mechanism of the power transmission tower; calculating the annual instability probability of the landslide by adopting an FLAC3D-Monte Carlo method; establishing a vulnerability evaluation model of the power transmission tower under the action of the landslide; and completing the landslide risk evaluation of the power transmission tower based on a model of risk = risk * vulnerability * economic value. The invention further provides a corresponding risk evaluation system. According to the method, the power transmission tower failure model is established, landslide deformation and tower failure are associated, quantitative and refined evaluation of the risk of the power transmission tower in the landslide area is achieved, and a new technical means is provided for geological disaster risk management and control of power grid facilities in the mountainous area.

Description

Technical Field

[0001] The invention relates to the technical field of disaster risk assessment research, and in particular to a landslide disaster risk assessment method and system based on a transmission tower failure model. Background Art

[0002] In recent years, with the rapid development of economy, my country has built a super-long power grid across a large area, which inevitably needs to pass through areas with complex geological conditions along the way. As an important part of the power transmission network, transmission towers need to avoid mutual influence with other human activities as much as possible, so they are mostly built on sparsely populated steep slopes of mountains, which greatly increases the possibility of transmission towers being affected by landslides and geological disasters.

[0003] Landslides are the most common geological disasters in mountainous areas and one of the main threats to power grid facilities in mountainous areas. Power grid accidents such as transmission tower tilting, line breaking and tripping caused by landslides occur frequently, which has an adverse impact on the country's economic construction and people's daily lives.

[0004] At present, the risk assessment of single landslide mainly includes three aspects: landslide hazard assessment, vulnerability assessment of disaster-bearing body, and landslide risk assessment. In the landslide hazard assessment, the probability of landslide instability or annual instability of landslide is usually used to indicate the possibility of landslide occurrence in the deformation stage. For landslides in the destruction stage, the landslide hazard assessment can be completed in combination with the disaster-causing scope of the landslide; the vulnerability assessment of disaster-bearing body often adopts the method of selecting vulnerability assessment indicators, constructing a vulnerability assessment model, and combining the value of the disaster-bearing body to complete the vulnerability assessment. Finally, the "risk = hazard × vulnerability × economic value" model is used to complete the transmission tower landslide risk assessment.

[0005] Panzhou City, Guizhou Province is located in the Wumeng Mountain area, which is a typical karst landform with high mountains, steep slopes and deep valleys. The natural environment is easily damaged, geological disasters occur frequently, and landslide geological disasters are the most developed. In addition, the transmission lines are distributed in a network and densely distributed. Transmission towers are inevitably built on steep slopes, ridges, landslides and other geological disaster-prone areas. In order to effectively improve the level of geological disaster risk management of power grids and reduce the losses caused by geological disasters, it is of great significance to conduct risk assessment research on landslide geological disasters for transmission towers, which are the core components of power grid facilities. The existing single landslide risk assessment method lacks consideration of the changing relationship between the landslide geological body and the transmission tower disaster-bearing body. Therefore, establishing a landslide risk assessment method based on the transmission tower failure model is a technical problem that needs to be solved urgently. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention is proposed.

[0007] Therefore, the problem to be solved by the present invention is that the existing single landslide risk assessment method lacks consideration of the changing relationship between the landslide geological body and the transmission tower hazard-bearing body.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] In a first aspect, an embodiment of the present invention provides a landslide disaster risk assessment method based on a transmission tower failure model, which includes conducting a detailed survey of the landslide area, identifying the engineering geological conditions of the landslide area, the deformation characteristics of the landslide, and the deformation characteristics of the transmission tower, deriving the landslide deformation failure mode and deformation stage, and obtaining the deformation relationship between the transmission tower and the ground surface;

[0010] Conduct surveys in the landslide area and obtain the physical and mechanical parameters of the rock and soil through field and indoor tests; use FLAC3D and ANAYS numerical simulation software to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide sliding, and verify the numerical simulation results with field monitoring data;

[0011] The FLAC3D-Monte Carlo method is used to calculate the probability of landslide instability under different rainfall conditions, and the annual probability of landslide instability under the corresponding conditions is calculated. The annual probability of landslide instability is used to represent the danger of landslide.

[0012] Based on the failure model of transmission towers, a vulnerability assessment model of transmission towers under landslides is established;

[0013] Based on the landslide hazard assessment and transmission tower vulnerability assessment, the “risk = hazard × vulnerability × economic value” model is used to complete the transmission tower landslide risk assessment.

[0014] As a preferred solution of the landslide disaster risk assessment method based on the transmission tower failure model of the present invention, the following steps may be specifically adopted to survey the landslide area and find out the engineering geological conditions, landslide deformation characteristics and transmission tower deformation characteristics of the landslide area:

[0015] Conduct surveys in the landslide area to identify the engineering geological conditions, deformation characteristics of the landslide, and deformation characteristics of the transmission towers, and obtain recent on-site monitoring data of the transmission towers and the ground surface;

[0016] According to the on-site monitoring data and rainfall data, it is concluded that rainfall is the main inducing factor;

[0017] Based on the results of the field investigation and combined with the field monitoring data, the deformation failure mode and deformation stage of the landslide were obtained;

[0018] Based on the field investigation results and combined with the field monitoring data, the deformation relationship between the transmission tower and the ground surface is obtained.

[0019] As a preferred solution of the landslide disaster risk assessment method based on the transmission tower failure model of the present invention, the FLAC3D-Monte Carlo method is used to calculate the landslide instability probability under different rainfall conditions, and the annual landslide instability probability under the corresponding conditions is calculated. The danger of the landslide is expressed by the annual landslide instability probability. Specifically, the following steps can be adopted:

[0020] Conduct surveys on the landslide area, obtain the physical and mechanical parameters of the rock and soil through field and indoor tests, build a three-dimensional geological model and numerical model of the landslide, and complete the numerical simulation of landslide deformation based on FLAC3D numerical simulation software;

[0021] Collect the design data of transmission towers, obtain the material parameters of the poles, build a numerical model of the transmission towers, and complete the numerical simulation of the deformation and failure of the transmission towers based on ANSYS numerical simulation software;

[0022] Analyze the ANSYS numerical simulation results to obtain the deformation failure model and mechanism of transmission towers under landslides;

[0023] The survey of the landslide area and obtaining the physical and mechanical parameters of the rock and soil through field tests and indoor tests include the following steps:

[0024] The steps for field testing can be as follows:

[0025] During the on-site investigation, the remote sensing image data of the site was obtained using the UAV 3D oblique photography technology, and the point cloud data and preliminary contour lines were generated through Pix4dMapper;

[0026] The generated point cloud data and preliminary contour lines are processed in Global Mapper to obtain processed contour lines;

[0027] The processed contour lines are brought into Rhino software to establish a three-dimensional geological model, and a three-dimensional numerical model of the landslide is established according to the development characteristics of the landslide;

[0028] The natural working condition and the extreme rainfall working condition are selected as the calculation working conditions. The natural working condition is used to verify with the actual monitoring data, and the extreme rainfall condition is used to obtain the whole process of deformation and failure of the transmission tower under the action of landslide sliding.

[0029] The rainfall intensity under different return periods is calculated according to the rainstorm intensity formula in the "New Generation Rainstorm Intensity Formula for Chinese Cities" to determine the rainfall intensity under different return periods in the calculation conditions. The calculation formula is as follows:

[0030]

[0031] Where: i is the rainfall intensity; T is the rainfall return period; t is the rainfall duration; this expression is applicable to Panzhou City, Guizhou Province;

[0032] The modified Green-Ampt model used this time assumes that the soil at different depths has the same initial moisture content before infiltration. During infiltration, there is a wetting front in the soil layer, which divides the soil into saturated and unsaturated areas. The infiltration depth corresponding to different rainfall intensities in the calculation conditions is determined according to the modified Green-Ampt model. The formula for the non-waterlogging infiltration part is as follows:

[0033]

[0034] Among them: y is the infiltration depth; t is the rainfall duration; q is the rainfall intensity; is the slope gradient, is the saturated water content; is the initial water content;

[0035] The displacements of the four tower feet of the transmission tower at the surface projection are monitored separately, and the landslide stability division is constructed according to the analysis of the numerical simulation results. The displacements of the monitoring points are simulated and used as the displacements of the tower feet and as the input conditions for the subsequent numerical simulation of the transmission tower.

[0036] As a preferred solution of the landslide disaster risk assessment method based on the transmission tower failure model of the present invention, wherein: the design data of the transmission tower is collected, the material parameters of the pole are obtained, the numerical model of the transmission tower is constructed, and the numerical simulation of the deformation failure of the transmission tower is completed based on the ANSYS numerical simulation software. Specifically, the following steps can be adopted:

[0037] The failure criterion of the transmission tower is established, and the maximum relative displacement of the tower foot is defined. The maximum relative displacement of the tower foot is characterized by calculating the relative displacement of the maximum tower foot displacement and the minimum tower foot displacement in the X and Z directions in the corresponding directions, and then vectorizing the relative displacements in the X and Z directions. The calculation formula for the maximum relative displacement of the tower foot is as follows:

[0038]

[0039] Where: Δx is the maximum relative displacement of the tower foot (mm); x1 is the displacement value of the tower foot with the largest displacement in the X direction; x2 is the displacement value of the tower foot with the smallest displacement in the X direction; z1 is the displacement value of the tower foot with the largest displacement in the Z direction; z2 is the displacement value of the tower foot with the smallest displacement in the Z direction;

[0040] The landslide deformation results in an increase in the maximum relative displacement of the tower foot, which causes an increase in the internal force of the rod and the overall deformation of the tower. According to the yield degree of the rod and the overall inclination degree of the tower, appropriate failure indicators of the transmission tower are selected. The failure indicators of the transmission tower are equivalent stress and the center displacement of the tower top.

[0041] The transmission tower angle steel is made of plastic material. The yield degree of the rod is characterized by the rod being in a stress state. When the distortion energy density of the rod reaches the distortion energy density of the plastic material when it yields in uniaxial tension, the rod yields and fails. This strength theory is called the Von Mises criterion. The corresponding strength judgment calculation formula is:

[0042]

[0043] Where: eq is the Von Mises equivalent stress (MPa); σ1, σ2, and σ3 are the first principal stress, the second principal stress, and the third principal stress (MPa), respectively; σ is the allowable stress of the material (MPa). In this study, the yield stress of the rod material is taken. As the internal force of the rod increases, when the equivalent stress exceeds the yield stress of the rod, the rod fails;

[0044] The specific failure criteria are as follows:

[0045] The main material or the diagonal material yields in its entire section, and the equivalent stress reaches the yield strength of the main material or the diagonal material. The yield strengths of the main material and the diagonal material are 345MPa and 235MPa respectively. When either the main material or the diagonal material yields, the transmission tower is considered to have failed.

[0046] According to Article 5.1.4 of the specification "DLT 741-2019 Overhead Transmission Line Operation Regulations", the inclination of transmission towers below 50m must be less than 1% of the tower height;

[0047] Use the field survey and transmission tower design data to establish a transmission tower numerical model, and complete the transmission tower numerical simulation in ANSYS;

[0048] The coordinate system in ANSYS is consistent with that in FLAC3D, and the output results in FLAC3D are used as the input results of each tower foot in ANSYS;

[0049] The analysis of ANSYS numerical simulation results to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide can be carried out in the following steps:

[0050] Analyze the internal force cloud map, displacement cloud map, equivalent stress cloud map, and failure index of the transmission tower, wherein the internal force cloud map of the transmission tower is characterized by axial force, shear force, bending moment, and torque;

[0051] By comparing the relationship between the two failure indicators and the maximum relative displacement of the tower foot, the corresponding relationship between the actual deformation failure of the transmission tower and the failure criterion is obtained, that is, the failure mechanism of the transmission tower is obtained.

[0052] As a preferred solution of the landslide disaster risk assessment method based on the transmission tower failure model of the present invention, the FLAC3D-Monte Carlo method is used to calculate the probability of landslide instability under different rainfall conditions, and the following steps can be adopted:

[0053] The FLAC3D-Monte Carlo method is used to calculate the probability of landslide instability and the annual probability of landslide instability is calculated;

[0054] The annual landslide instability probability is calculated based on the conversion formula between the landslide instability probability and the annual landslide instability probability.

[0055] The method of calculating the landslide instability probability by using the FLAC3D-Monte Carlo method to calculate the annual landslide instability probability may specifically include the following steps:

[0056] FLAC3D-Monte Carlo method characterizes the method of integrating Monte Carlo random numbers into the FLAC3D numerical calculation model. The calculation steps are as follows;

[0057] Selection and processing of random variables: Among the various geotechnical parameters that affect the stability of the landslide, the parameters that have the greatest impact on the reliability analysis results are selected, which are generally the cohesion and internal friction angle of the soil. Therefore, cohesion and internal friction angle are selected as random variables, and N groups of random numbers are generated in the computer language;

[0058] The initial geostress field is obtained according to the FLAC3D solution process and the constructed three-dimensional geological body numerical model;

[0059] Substitute the N groups of random numbers of cohesion and internal friction angle in the selection and processing of random variables to obtain the corresponding N groups of safety factors;

[0060] Statistics and analysis are performed on N groups of safety factors to calculate the failure probability of the slope;

[0061] Based on the three-dimensional geological body numerical model established by FLAC3D, the working conditions and rock and soil parameters are changed, and other parameters remain unchanged. The rainfall intensity and infiltration depth under different recurrence periods are calculated. The rainfall intensity and infiltration depth are calculated according to the formula given above, and the probability of landslide instability under different rainfall conditions is obtained by substituting them into the formula.

[0062] The step of calculating the annual landslide instability probability according to the conversion formula between the landslide instability probability and the annual landslide instability probability may specifically include the following steps:

[0063] The instability of landslides under different working conditions includes the probability of sliding of the landslide itself, the randomness and uncertainty of the inducing factors, and the determination of the annual instability probability of landslides is determined by the possibility of the two occurring together;

[0064] When rainfall is the triggering factor, the extreme rainfall event is regarded as event A and the landslide instability is regarded as event B. The annual probability expression of landslide instability is:

[0065] P=P[A]P[B / A]

[0066] Where: P is the annual probability of landslide instability; P[A] is the probability of extreme rainfall events; P[B / A] is the probability of landslide instability under extreme rainfall conditions;

[0067] The probability of landslide instability under extreme rainfall conditions is calculated by the FLAC3D-Monte Carlo method. The probability of extreme rainfall events is the inverse of the return period of extreme rainfall, so the annual probability of landslide instability under extreme rainfall is expressed as:

[0068] P=P[B / A] / T

[0069] Where: P is the annual probability of landslide instability; P[B / A] is the probability of landslide instability under extreme rainfall conditions; T is the rainfall return period (a);

[0070] The obtained landslide instability probability is converted into the annual landslide instability probability of the corresponding working condition.

[0071] As a preferred solution of the landslide disaster risk assessment method based on the failure model of the transmission tower described in the present invention, wherein: the vulnerability assessment model of the transmission tower under the action of landslide is established based on the failure model of the transmission tower, which specifically includes the following steps:

[0072] According to the above numerical simulation, the only failure criterion that meets the transmission tower is found, and the failure mode of the transmission tower is determined according to the numerical simulation results. The failure modes of the transmission tower include failure of oblique material, failure of main material, and overall tilt failure.

[0073] A transmission tower vulnerability assessment model is proposed based on the transmission tower failure model;

[0074] Obtain the vulnerability value of transmission towers under different rainfall conditions;

[0075] The proposed transmission tower vulnerability assessment model based on the transmission tower failure model may specifically include the following steps:

[0076] According to the failure mode of the transmission tower, the corresponding failure threshold and the corresponding maximum relative displacement threshold of the tower foot are obtained;

[0077] According to the relationship between the actual maximum relative displacement of the tower foot and the maximum relative displacement of the tower foot, the expression of the transmission tower vulnerability evaluation model is as follows:

[0078]

[0079] Where: V is the vulnerability value; Δx实际 is the maximum relative displacement of the tower foot (mm), which is the composite displacement of the maximum relative displacement of the tower foot in the X direction and the maximum relative displacement in the Z direction. Its calculation formula is shown in the calculation formula of the maximum relative displacement of the tower foot;

[0080] When Δx 实际 Less than the maximum allowable value Δx 阈值 When , the vulnerability value is the ratio of its actual value to the maximum allowed value;

[0081] When Δx 实际 Greater than or equal to the maximum allowable value Δx 阈值 When the tower has completely failed,

[0082] Therefore, the vulnerability value is 1 at this time.

[0083] As a preferred solution of the landslide disaster risk assessment method based on the transmission tower failure model of the present invention, the landslide hazard assessment and transmission tower vulnerability assessment specifically include the following steps:

[0084] The risk is characterized by the economic losses, life losses and environmental damage losses caused by disasters in various disaster-prone bodies under certain conditions and within a certain period of time, that is, risk degree = hazard degree × vulnerability degree;

[0085] According to the basic definition of risk, the risk includes the danger, vulnerability of the landslide disaster-bearing body, the number of disaster-bearing bodies, and the value of the transmission tower; the specific calculation expression of risk is;

[0086] R=H×V×E

[0087] Where R is the landslide risk; H is the landslide hazard, expressed as the annual probability of landslide instability; V is the vulnerability of the transmission tower; E is the value of the transmission tower;

[0088] Obtain the value of the transmission tower according to the design data of the transmission tower;

[0089] The annual risk value of transmission tower landslide under different rainfall conditions is obtained.

[0090] In a second aspect, an embodiment of the present invention provides a landslide disaster risk assessment system based on a transmission tower failure model, which includes an acquisition module, which conducts a detailed survey of the landslide area, finds out the engineering geological conditions of the landslide area, the deformation characteristics of the landslide, and the deformation characteristics of the transmission tower, obtains the landslide deformation failure mode and deformation stage, and obtains the deformation relationship between the transmission tower and the ground surface;

[0091] Verification module: survey the landslide area and obtain the physical and mechanical parameters of the rock and soil through field and indoor tests; use FLAC3D and ANAYS numerical simulation software to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide sliding, and verify the numerical simulation results with field monitoring data;

[0092] The calculation module uses the FLAC3D-Monte Carlo method to calculate the probability of landslide instability under different rainfall conditions, and calculates the annual probability of landslide instability under the corresponding conditions, and uses the annual probability of landslide instability to represent the danger of the landslide;

[0093] Building a module to establish a vulnerability assessment model for transmission towers under landslides based on the failure model of transmission towers;

[0094] The evaluation module, based on the landslide hazard assessment and transmission tower vulnerability assessment, adopts the "risk = hazard × vulnerability × economic value" model to complete the transmission tower landslide risk assessment.

[0095] In a third aspect, an embodiment of the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program instructions are executed by the processor, the steps of the landslide disaster risk assessment method based on the transmission tower failure model as described in the first aspect of the present invention are implemented.

[0096] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program instructions are executed by a processor, the steps of the landslide hazard risk assessment method based on the transmission tower failure model as described in the first aspect of the present invention are implemented.

[0097] The beneficial effects of the present invention are as follows: the present invention is based on the achievements of single landslide risk assessment, landslide failure probability calculation based on rainfall infiltration hydrological model, slope stability calculation model and FLAC3D-Monte Carlo method, and obtains the whole process of deformation and failure of transmission towers, thereby proposing a landslide risk assessment method suitable for transmission towers.

[0098] The feasibility and rationality of the numerical simulation of landslides and transmission towers, the calculation model of the annual probability of landslide damage and the key technologies adopted in the present invention have been verified, and the landslide risk assessment based on the transmission tower failure model has been realized, enriching the types of research methods for landslide risk assessment of transmission towers.

[0099] The invention has a reasonable concept and a simple operation process. The landslide risk assessment results based on the transmission tower failure model can provide theoretical and methodological support for the geological disaster risk management and control of power grid facilities in mountainous areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0101] Figure 1 It is a flow chart of the landslide disaster risk assessment method based on the transmission tower failure model;

[0102] Figure 2 Computer equipment diagram for landslide hazard risk assessment method based on transmission tower failure model;

[0103] Figure 3 A transmission tower site survey diagram of an embodiment of a landslide disaster risk assessment method based on a transmission tower failure model;

[0104] Figure 4 A surface crack map of an embodiment of a landslide hazard risk assessment method based on a transmission tower failure model;

[0105] Figure 5 It is an orthophoto image of an embodiment of a landslide disaster risk assessment method based on a transmission tower failure model;

[0106] Figure 6 is a cross-sectional diagram of an embodiment of a landslide disaster risk assessment method based on a transmission tower failure model;

[0107] Figure 7 A map of on-site monitoring locations for an embodiment of a landslide disaster risk assessment method based on a transmission tower failure model;

[0108] Figure 8 It is a graph of on-site displacement monitoring of an embodiment of a landslide disaster risk assessment method based on a transmission tower failure model;

[0109] Fig. 9 The comparison diagram of daily rainfall and total surface displacement is an example of a landslide disaster risk assessment method based on a transmission tower failure model;

[0110] Fig.10 A three-dimensional numerical model of landslide is provided as an embodiment of a landslide disaster risk assessment method based on a transmission tower failure model;

[0111] Fig.11 It is a numerical simulation monitoring point location map of an embodiment of a landslide disaster risk assessment method based on a transmission tower failure model;

[0112] Fig.12 An embodiment of a landslide disaster risk assessment method based on a transmission tower failure model is a transmission tower numerical model;

[0113] Fig.13 It is an equivalent stress-tower foot maximum relative displacement curve diagram of an embodiment of a landslide disaster risk assessment method based on a transmission tower failure model;

[0114] Fig.14 It is a graph showing the maximum relative displacement of the tower top center displacement and the tower foot in the embodiment of the landslide disaster risk assessment method based on the failure model of the transmission tower;

[0115] Fig.15 The figure is a diagram of a transmission tower deformation failure model according to an embodiment of a landslide disaster risk assessment method based on a transmission tower failure model. DETAILED DESCRIPTION

[0116] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0117] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0118] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0119] Example 1

[0120] Reference Figure 1-2 , which is the first embodiment of the present invention, and provides a landslide disaster risk assessment method based on a transmission tower failure model, comprising:

[0121] S100: Conduct a detailed survey of the landslide area to identify the engineering geological conditions, deformation characteristics of the landslide, and deformation characteristics of the transmission tower, derive the landslide deformation failure mode and deformation stage, and obtain the deformation relationship between the transmission tower and the ground surface;

[0122] S102: Conduct a detailed survey of the landslide area to identify the engineering geological conditions, landslide deformation characteristics, and transmission tower deformation characteristics of the landslide area. The specific steps are as follows:

[0123] Conduct detailed surveys of the landslide area to identify the engineering geological conditions, landslide deformation characteristics, and transmission tower deformation characteristics of the landslide area, and obtain recent on-site monitoring data of transmission towers and the ground surface;

[0124] According to the on-site monitoring data and rainfall data, it is concluded that rainfall is the main inducing factor;

[0125] Based on the results of the field investigation and combined with the field monitoring data, the deformation failure mode and deformation stage of the landslide were obtained;

[0126] Based on the field investigation results and combined with the field monitoring data, the deformation relationship between the transmission tower and the ground surface is obtained.

[0127] S200: Conduct a detailed survey of the landslide area and obtain the physical and mechanical parameters of the rock and soil through field and indoor tests; use FLAC3D and ANAYS numerical simulation software to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide sliding, and verify the numerical simulation results with field monitoring data;

[0128] S201: Calculate the probability of landslide instability under different rainfall conditions using the FLAC3D-Monte Carlo method, and obtain the annual probability of landslide instability under the corresponding conditions. The annual probability of landslide instability is used to represent the danger of the landslide. The specific steps are as follows:

[0129] Conduct detailed surveys of the landslide area, obtain the physical and mechanical parameters of the rock and soil through field and indoor tests, build a three-dimensional geological model and numerical model of the landslide, and complete the numerical simulation of landslide deformation based on FLAC3D numerical simulation software;

[0130] Collect the design data of transmission towers, obtain the material parameters of the poles, build a numerical model of the transmission towers, and complete the numerical simulation of the deformation and failure of the transmission towers based on ANSYS numerical simulation software;

[0131] Analyze the ANSYS numerical simulation results to obtain the deformation failure model and mechanism of transmission towers under landslides;

[0132] Among them, a detailed survey of the landslide area is carried out, and the physical and mechanical parameters of the rock and soil are obtained through field tests and indoor tests, which includes the following steps:

[0133] In the field investigation, the remote sensing image data of the site was obtained by using the three-dimensional oblique photography technology of unmanned aerial vehicles, and the point cloud data and preliminary contour lines were generated by Pix4dMapper, which were then processed in Global Mapper to obtain the processed contour lines. Secondly, the processed contour lines were used to establish a three-dimensional geological model in Rhino software, and finally a three-dimensional numerical model of the landslide was established according to the development characteristics of the landslide.

[0134] The natural working condition and the extreme rainfall working condition are selected as the calculation working conditions. The natural working condition is used to verify with the actual monitoring data, and the extreme rainfall condition is used to obtain the whole process of deformation and failure of the transmission tower under the action of landslide sliding.

[0135] The rainfall intensity under different return periods is calculated according to the rainstorm intensity formula in the "New Generation Rainstorm Intensity Formula for Chinese Cities" to determine the rainfall intensity under different return periods in the calculation conditions. The calculation formula is as follows:

[0136]

[0137] Where: i is the rainfall intensity; T is the rainfall return period; t is the rainfall duration; this expression is applicable to Panzhou City, Guizhou Province;

[0138] S202: The modified Green-Ampt model used this time assumes that the soil at different depths has the same initial moisture content before infiltration. During infiltration, there is an obvious wetting front in the soil layer, which divides the soil into saturated and unsaturated areas. The infiltration depth corresponding to different rainfall intensities in the calculation conditions is determined according to the modified Green-Ampt model. The formula for the non-waterlogging infiltration part is:

[0139]

[0140] Among them: y is the infiltration depth; t is the rainfall duration; q is the rainfall intensity; is the slope gradient, is the saturated water content; is the initial water content;

[0141] The displacements of the four tower feet of the transmission tower at the surface projection are monitored separately. The landslide stability division is constructed based on the analysis of the numerical simulation results. The displacement of the monitoring point is simulated and used as the displacement of the tower foot and as the input condition for the subsequent numerical simulation of the transmission tower.

[0142] Collect the design data of the transmission tower, obtain the material parameters of the pole, build the numerical model of the transmission tower, and complete the numerical simulation of the deformation and failure of the transmission tower based on the ANSYS numerical simulation software. The specific steps are as follows:

[0143] First, the failure criteria of the transmission tower should be established, and the maximum relative displacement of the tower foot Δx should be defined: the maximum tower foot displacement and the minimum tower foot displacement are calculated in the X and Z directions to obtain the relative displacement in the corresponding directions, and then the relative displacements in the X and Z directions are vector synthesized. The calculation formula of the maximum relative displacement of the tower foot is as follows:

[0144]

[0145] Where: Δx is the maximum relative displacement of the tower foot (mm); x1 is the displacement value of the tower foot with the largest displacement in the X direction; x2 is the displacement value of the tower foot with the smallest displacement in the X direction; z1 is the displacement value of the tower foot with the largest displacement in the Z direction; z2 is the displacement value of the tower foot with the smallest displacement in the Z direction;

[0146] The landslide deformation leads to an increase in the maximum relative displacement Δx of the tower foot, which in turn causes an increase in the internal force of the rod and the overall deformation of the tower. Therefore, appropriate indicators are selected from the two aspects of the yield degree of the rod and the overall inclination degree of the tower, that is, the equivalent stress and the center displacement of the tower top are selected as the failure indicators of the transmission tower.

[0147] For the plastic material such as the angle steel of the transmission tower, no matter what stress state the rod is in, when its distortion energy density reaches the distortion energy density of the material when it yields in uniaxial tension, the rod will yield and fail. This strength theory is called the VonMises criterion, and the corresponding strength judgment calculation formula is:

[0148]

[0149] Where: eq is the Von Mises equivalent stress (MPa); σ1, σ2, and σ3 are the first principal stress, the second principal stress, and the third principal stress (MPa), respectively; σ is the allowable stress of the material (MPa). In this study, the yield stress of the rod material is taken. As the internal force of the rod increases, when the equivalent stress exceeds the yield stress of the rod, the rod can be considered to have failed.

[0150] The specific failure criteria are as follows:

[0151] The main material or the diagonal material yields in its entire section, and the equivalent stress reaches the yield strength of the main material or the diagonal material. The yield strengths of the main material and the diagonal material are 345MPa and 235MPa respectively. When either the main material or the diagonal material yields, the transmission tower is considered to have failed.

[0152] According to Article 5.1.4 of the specification "DLT 741-2019 Overhead Transmission Line Operation Regulations", the inclination of transmission towers below 50m must be less than 1% of the tower height;

[0153] Use the field survey and transmission tower design data to establish a transmission tower numerical model, and complete the transmission tower numerical simulation in ANSYS;

[0154] The coordinate system in ANSYS is consistent with that in FLAC3D, and the output results in FLAC3D are used as the input results of each tower foot in ANSYS;

[0155] Among them, the ANSYS numerical simulation results are analyzed to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide. The specific steps are as follows:

[0156] Analyze the internal force cloud map, displacement cloud map, equivalent stress cloud map, and failure index of the transmission tower. The internal force cloud map of the transmission tower is characterized by axial force, shear force, bending moment, and torque;

[0157] By comparing the relationship between the two failure indicators and the maximum relative displacement of the tower foot, the corresponding relationship between the actual deformation failure of the transmission tower and the failure criterion is obtained, that is, the failure mechanism of the transmission tower is obtained.

[0158] S300: The FLAC3D-Monte Carlo method is used to calculate the probability of landslide instability under different rainfall conditions, and the annual probability of landslide instability under the corresponding conditions is calculated. The annual probability of landslide instability is used to represent the danger of landslide.

[0159] S301: The FLAC3D-Monte Carlo method is used to calculate the probability of landslide instability under different rainfall conditions. The following steps can be used:

[0160] The FLAC3D-Monte Carlo method is used to calculate the landslide instability probability, and then the annual landslide instability probability is calculated;

[0161] The annual landslide instability probability is calculated based on the conversion formula between the landslide instability probability and the annual landslide instability probability.

[0162] The specific steps of using the FLAC3D-Monte Carlo method to calculate the landslide instability probability and then calculating the annual landslide instability probability include the following:

[0163] The FLAC3D-Monte Carlo method is a method that integrates the idea of ​​Monte Carlo random numbers into the FLAC3D numerical calculation model. The calculation steps are as follows;

[0164] Selection and processing of random variables: Among the various geotechnical parameters that affect the stability of the landslide, the parameters that have the greatest impact on the reliability analysis results are selected, generally the cohesion c and internal friction angle of the soil. So choose c, As random variables, N sets of random numbers are generated in computer language;

[0165] The initial geostress field is obtained according to the FLAC3D solution process and the constructed three-dimensional geological body numerical model;

[0166] The selection and processing of random variables in N groups of random numbers c, Substitute to get the corresponding N groups of safety factors;

[0167] Statistics and analysis are performed on N groups of safety factors to calculate the failure probability of the slope;

[0168] Based on the three-dimensional geological body numerical model established by FLAC3D in S2-1 above, the working conditions and rock and soil parameters are changed, and the other parameters remain unchanged. At the same time, the rainfall intensity and infiltration depth under different recurrence periods are calculated. The rainfall intensity is calculated according to formula (1), and the infiltration depth is calculated according to formula (2). Substitute them into the formula to obtain the probability of landslide instability under different rainfall conditions;

[0169] The calculation of the annual landslide instability probability according to the conversion formula between the landslide instability probability and the annual landslide instability probability may specifically include the following steps:

[0170] The possibility of landslide instability under different working conditions should take into account the probability of the landslide itself sliding, as well as the randomness and uncertainty of the inducing factors, that is, the determination of the annual probability of landslide instability is determined by the common probability of the two. When rainfall is the inducing factor, extreme rainfall events can be regarded as event A, and landslide instability can be regarded as event B. The expression of the annual probability of landslide instability Р is:

[0171] P=P[A]P[B / A]

[0172] Where: P is the annual probability of landslide instability; P[A] is the probability of extreme rainfall events; P[B / A] is the probability of landslide instability under extreme rainfall conditions;

[0173] The probability of landslide instability under extreme rainfall conditions (P[B / A]) can be calculated by the FLAC3D-Monte Carlo method; the probability of extreme rainfall events (P[A]) is the inverse of the return period of extreme rainfall, so the annual probability of landslide instability under extreme rainfall is;

[0174] P=P[B / A] / T

[0175] Where: P is the annual probability of landslide instability; P[B / A] is the probability of landslide instability under extreme rainfall conditions; T is the rainfall return period (a);

[0176] The obtained landslide instability probability is converted into the annual landslide instability probability of the corresponding working condition.

[0177] S400: Establish a vulnerability assessment model for transmission towers under landslides based on the failure model of transmission towers;

[0178] S401: Establishing a vulnerability assessment model of transmission towers under landslide based on the failure model of transmission towers, which specifically includes the following steps:

[0179] According to the above numerical simulation, the only failure criterion that meets the transmission tower is found, that is, the failure mode of the transmission tower is determined according to the numerical simulation results. The failure modes of the transmission tower include oblique material failure, main material failure, and overall tilt failure.

[0180] A transmission tower vulnerability assessment model is proposed based on the transmission tower failure model;

[0181] Obtain the vulnerability value of transmission towers under different rainfall conditions;

[0182] Among them, a transmission tower vulnerability assessment model is proposed based on the transmission tower failure model, which may include the following steps:

[0183] According to the failure mode of the transmission tower, find the corresponding failure threshold and the corresponding maximum relative displacement threshold of the tower foot;

[0184] According to the relationship between the actual maximum relative displacement of the tower foot and the maximum relative displacement of the tower foot, the transmission tower vulnerability assessment model is established as follows;

[0185]

[0186] Where: V is the vulnerability value; Δx 实际 is the maximum relative displacement of the tower foot (mm), which is the composite displacement of the maximum relative displacement of the tower foot in the X direction and the maximum relative displacement in the Z direction. Its calculation formula is shown in the calculation formula of the maximum relative displacement of the tower foot;

[0187] When Δx 实际 Less than the maximum allowable value Δx 阈值 When , the vulnerability value is the ratio of its actual value to the maximum allowed value;

[0188] When Δx 实际 Greater than or equal to the maximum allowable value Δx 阈值 When the tower is considered to have completely failed,

[0189] Therefore, the vulnerability value is 1 at this time.

[0190] S500: Based on the landslide hazard assessment and transmission tower vulnerability assessment, the “risk = hazard × vulnerability × economic value” model is used to complete the transmission tower landslide risk assessment.

[0191] S501: Based on the landslide hazard assessment and transmission tower vulnerability assessment, it specifically includes the following steps:

[0192] Risk refers to the economic losses, life losses and environmental damage losses caused by the disaster process that various types of hazard-bearing bodies may encounter under certain conditions and within a certain period of time, that is, risk = hazard × vulnerability; according to the basic definition of risk, risk should include hazard, vulnerability of landslide hazard-bearing bodies and the number or value of hazard-bearing bodies; the specific calculation expression of risk is;

[0193] R=H×V×E

[0194] Where R is the landslide risk; H is the landslide hazard, expressed as the annual probability of landslide instability; V is the vulnerability of the transmission tower; E is the value of the transmission tower;

[0195] Obtain the value of the transmission tower according to the design data of the transmission tower;

[0196] The annual risk value of transmission tower landslide under different rainfall conditions is obtained.

[0197] Furthermore, this embodiment also provides a landslide disaster risk assessment system based on a transmission tower failure model, comprising:

[0198] The acquisition module conducts a detailed survey of the landslide area, identifies the engineering geological conditions of the landslide area, the deformation characteristics of the landslide, and the deformation characteristics of the transmission tower, derives the landslide deformation failure mode and deformation stage, and obtains the deformation relationship between the transmission tower and the ground surface;

[0199] Verification module: Conduct detailed survey of the landslide area and obtain the physical and mechanical parameters of the rock and soil through field and indoor tests; use FLAC3D and ANAYS numerical simulation software to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide sliding, and verify the numerical simulation results with field monitoring data;

[0200] The calculation module uses the FLAC3D-Monte Carlo method to calculate the probability of landslide instability under different rainfall conditions, and calculates the annual probability of landslide instability under the corresponding conditions, and uses the annual probability of landslide instability to represent the danger of the landslide;

[0201] Building a module to establish a vulnerability assessment model for transmission towers under landslides based on the failure model of transmission towers;

[0202] The evaluation module, based on the landslide hazard assessment and transmission tower vulnerability assessment, adopts the "risk = hazard × vulnerability × economic value" model to complete the transmission tower landslide risk assessment.

[0203] This embodiment also provides a computer device, which is applicable to the case of a landslide disaster risk assessment method based on a transmission tower failure model, and includes a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions to implement the landslide disaster risk assessment method based on a transmission tower failure model as proposed in the above embodiment.

[0204] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0205] This embodiment further provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for evaluating landslide disaster risk based on a transmission tower failure model as proposed in the above embodiment is implemented.

[0206] In summary, by conducting a detailed survey of the landslide area and obtaining the deformation relationship between the transmission tower and the ground surface, the correlation analysis between the landslide and the transmission tower deformation was realized, which provided basic data for subsequent risk assessment and was conducive to improving the accuracy of the assessment.

[0207] By using FLAC3D and ANSYS numerical simulation software, the deformation failure model and mechanism of transmission towers under the action of landslide sliding were obtained, and a quantitative description of the failure process of transmission towers was achieved, providing a theoretical basis for establishing a vulnerability assessment model.

[0208] By using the FLAC3D-Monte Carlo method to calculate the landslide instability probability and combining it with the rainfall recurrence period, the annual landslide instability probability is calculated, which achieves a quantitative characterization of the landslide hazard and improves the scientific nature of risk assessment.

[0209] By establishing a vulnerability assessment model based on the maximum relative displacement of the tower foot, a quantitative assessment of the vulnerability of transmission towers is achieved, providing key parameters for risk calculation.

[0210] By comprehensively considering the landslide hazard, vulnerability of transmission towers and economic value, a risk assessment model of "risk = hazard × vulnerability × economic value" was established, which achieved a comprehensive quantitative assessment of the landslide risk of transmission towers and provided a scientific basis for risk management and control decisions.

[0211] The present invention establishes a transmission tower failure model, associates landslide deformation with tower failure, and realizes a quantitative and refined assessment of the risk of transmission towers in landslide areas. It provides a new technical means for the geological disaster risk management of power grid facilities in mountainous areas and has important practical value.

[0212] Example 2

[0213] Reference Figure 2 - Fig.15 , which is the second embodiment of the present invention, and this embodiment provides a landslide disaster risk assessment method based on a transmission tower failure model. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0214] To better explain the present invention, the following is further described in conjunction with the Luoduo Village landslide in the embodiment:

[0215] Through multiple field investigations, it is known that the Luoduo Village landslide is a traction-type soil landslide that slides along the base surface and is currently in the accelerated deformation stage. Figure 3 ) is located within the landslide area, and the rods have no obvious deformation. The macroscopic deformation characteristics of the Luoduo Village landslide are mainly surface cracks and local small-scale landslides. Figure 4 ) is mainly concentrated in the rear part of the landslide, and the soil slides along the base surface on a small scale, mainly at the front edge shear outlet ( Figure 5 ).

[0216] Luoduocun landslide developed in the reverse slope composed of sandstone and mudstone interlayers of the Longtan Formation (P3l) of the Upper Permian System, with a rock formation dip of 259°∠29°. The sliding body is mainly Quaternary residual slope deposits (Q4el+dl), composed of clay intercalated with sandstone and mudstone fragments, with an average thickness of about 5m. The sliding body is about 65m long and 110m wide, with a thickness of about 2-7m, an average thickness of about 5m, and a volume of about 3.575×104m3 ( Figure 6 ).

[0217] Among them, the following step S100 is to preliminarily obtain the deformation relationship between the transmission tower and the landslide, that is, firstly conduct an on-site investigation of the landslide area, and find out the engineering geological conditions of the landslide area, the deformation characteristics of the landslide, and the deformation characteristics of the transmission tower by means of data collection and on-site monitoring, and install monitoring instruments on the surface and the tower ( Figure 7 ), and obtain the recent on-site monitoring data of the transmission tower and the ground surface. Secondly, based on the monitoring data, rainfall is obtained as the main inducing factor. Again, through the above analysis, the deformation failure mode and deformation stage of the landslide are obtained, and finally the deformation relationship between the transmission tower and the ground surface is obtained. Specifically, step S100 includes the following steps:

[0218] S100: Conduct a detailed survey of the landslide area to identify the engineering geological conditions, deformation characteristics of the landslide, and deformation characteristics of the transmission tower, derive the landslide deformation failure mode and deformation stage, and obtain the deformation relationship between the transmission tower and the ground surface;

[0219] S102: Conduct a detailed survey of the landslide area to identify the engineering geological conditions, landslide deformation characteristics, and transmission tower deformation characteristics of the landslide area. The specific steps are as follows:

[0220] Conduct a detailed survey of the landslide area to identify the engineering geological conditions, landslide deformation characteristics, and transmission tower deformation characteristics of the landslide area, and obtain recent on-site monitoring data of transmission towers and the ground surface ( Figure 8 );

[0221] According to the on-site monitoring data and rainfall data, it is concluded that rainfall is the main inducing factor. By comparing and analyzing the total surface displacement monitoring data of the landslide from July 2023 to January 2024 and the rainfall data in the landslide area, it is found that rainfall has a high correlation and hysteresis with surface deformation. It can be seen that rainfall is the main factor inducing the Luoduo Village landslide ( Fig. 9 );

[0222] According to the results of the field investigation and combined with the field monitoring data, the deformation failure mode and deformation stage of the landslide were obtained. It was concluded that the Luoduo Village landslide was a traction-type soil landslide sliding along the base cover and was currently in the accelerated deformation stage.

[0223] According to the results of the on-site investigation and combined with the on-site monitoring data, the deformation relationship between the transmission tower and the ground surface was obtained. The monitoring data of the transmission tower and the ground surface were compared and analyzed, and the relationship between the displacement of the transmission tower and the ground surface deformation was obtained: when the landslide occurred, the displacement of the monitoring point on the tower was synchronized with the ground displacement, but there was a difference in the values. The difference was mainly reflected in the Z-direction displacement. The average Z-direction displacement difference was about 9.6mm, which was relatively small.

[0224] Among them, the following step S200 is to obtain the deformation failure model and mechanism of the transmission tower, that is, firstly, through the means of on-site investigation and data collection in the landslide area, the numerical simulation of landslide deformation is completed, and then the numerical simulation of the transmission tower is completed. Finally, the ANSYS numerical simulation results are analyzed to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide.

[0225] S200: Conduct a detailed survey of the landslide area and obtain the physical and mechanical parameters of the rock and soil through field and indoor tests; use FLAC3D and ANAYS numerical simulation software to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide sliding, and verify the numerical simulation results with field monitoring data;

[0226] S201: Calculate the probability of landslide instability under different rainfall conditions using the FLAC3D-Monte Carlo method, and obtain the annual probability of landslide instability under the corresponding conditions. The annual probability of landslide instability is used to represent the danger of the landslide. The specific steps are as follows:

[0227] Conduct detailed surveys of the landslide area, obtain the physical and mechanical parameters of the rock and soil through field and indoor tests, build a three-dimensional geological model and numerical model of the landslide, and complete the numerical simulation of landslide deformation based on FLAC3D numerical simulation software;

[0228] Collect the design data of transmission towers, obtain the material parameters of the poles, build a numerical model of the transmission towers, and complete the numerical simulation of the deformation and failure of the transmission towers based on ANSYS numerical simulation software;

[0229] Analyze the ANSYS numerical simulation results to obtain the deformation failure model and mechanism of transmission towers under landslides;

[0230] Among them, a detailed survey of the landslide area is carried out, and the physical and mechanical parameters of the rock and soil are obtained through field tests and indoor tests, which includes the following steps:

[0231] In the field investigation, the remote sensing image data of the site was obtained by using the UAV 3D oblique photography technology, and the point cloud data and preliminary contour lines were generated by Pix4dMapper, which were then processed in Global Mapper to obtain the processed contour lines. Secondly, the processed contour lines were used to establish a 3D geological model in Rhino software. Finally, a 3D numerical model of the landslide was established according to the development characteristics of the landslide ( Fig.10 );

[0232] The natural working condition and the extreme rainfall working condition are selected as the calculation working conditions. The natural working condition is used to verify with the actual monitoring data, and the extreme rainfall condition is used to obtain the whole process of deformation and failure of the transmission tower under the action of landslide sliding.

[0233] The rainfall intensity under different return periods is calculated according to the rainstorm intensity formula in the "New Generation Rainstorm Intensity Formula for Chinese Cities" to determine the rainfall intensity under different return periods in the calculation conditions. The calculation formula is as follows:

[0234]

[0235] Where: i is the rainfall intensity; T is the rainfall return period; t is the rainfall duration; this expression is applicable to Panzhou City, Guizhou Province;

[0236] S202: The present invention is applicable to shallow landslides caused by rainfall infiltration, and the groundwater level is buried deep, and the groundwater level does not change during the entire rainfall infiltration process. The modified Green-Ampt model is selected. This model takes into account both the influence of slope inclination and the characteristics of unsaturated soil, and is applicable to both waterlogging infiltration and non-waterlogging infiltration modes. The assumption of the modified Green-Ampt model selected this time is that the soil at different depths has the same initial moisture content before infiltration. During infiltration, there is an obvious wetting front in the soil layer, which divides the soil into saturated and unsaturated areas. The infiltration depth corresponding to different rainfall intensities in the calculation condition is determined according to the modified Green-Ampt model, and the formula for the non-waterlogging infiltration part is expressed as:

[0237]

[0238] Where: y is the infiltration depth; t is the rainfall duration; q is the rainfall intensity; is the slope gradient, is the saturated water content; is the initial water content; the rainfall intensity q is 269 mm / d, the rainfall duration t is 1 day, the slope gradient α is the average slope of 20°, and the saturated water content Q is the initial water content. s and initial moisture content Q i The values ​​are 0.4 and 0.28 respectively, and the infiltration depth under extreme rainfall conditions is calculated to be 2238 mm. The calculation conditions for extreme rainfall are shown in Table 1.

[0239] Table 1 Extreme rainfall conditions

[0240]

[0241] Monitor the displacement of the four tower feet of the transmission tower at the projection point on the ground surface ( Fig.11 ), the landslide stability classification in the analysis of numerical simulation results refers to the "Landslide Prevention Engineering Investigation Code (DZ / T 32864-2016)" as shown in Table 2, the displacement of the monitoring point is simulated, which is used as the displacement of the tower foot and as the input condition for the subsequent numerical simulation of the transmission tower. It is found that the landslide is in a stable state under the natural state, and the displacement of the tower foot is small, and its displacement value is consistent with the monitoring result; the landslide is in an unstable state under extreme rainfall conditions, and the displacement of the tower foot is about 140-200mm. The displacement of tower foot 4 is the largest, up to 199mm, and the displacement of tower foot 2 is the smallest, 142mm. The deformation of the tower foot is mainly along the X direction and Z direction, and the displacement value in the Y direction is small and can be basically ignored.

[0242] Table 2 Classification of landslide stability states

[0243]

[0244] The displacements of the four tower feet of the transmission tower at the surface projection are monitored separately. The landslide stability division is constructed based on the analysis of the numerical simulation results. The displacement of the monitoring point is simulated and used as the displacement of the tower foot and as the input condition for the subsequent numerical simulation of the transmission tower.

[0245] Collect the design data of the transmission tower, obtain the material parameters of the pole, build the numerical model of the transmission tower, and complete the numerical simulation of the deformation and failure of the transmission tower based on the ANSYS numerical simulation software. The specific steps are as follows:

[0246] First, the failure criteria of the transmission tower should be established, and the maximum relative displacement of the tower foot Δx should be defined: the maximum tower foot displacement and the minimum tower foot displacement are calculated in the X and Z directions to obtain the relative displacement in the corresponding directions, and then the relative displacements in the X and Z directions are vector synthesized. The calculation formula of the maximum relative displacement of the tower foot is as follows:

[0247]

[0248] Where: Δx is the maximum relative displacement of the tower foot (mm); x1 is the displacement value of the tower foot with the largest displacement in the X direction; x2 is the displacement value of the tower foot with the smallest displacement in the X direction; z1 is the displacement value of the tower foot with the largest displacement in the Z direction; z2 is the displacement value of the tower foot with the smallest displacement in the Z direction;

[0249] The landslide deformation leads to an increase in the maximum relative displacement Δx of the tower foot, which in turn causes an increase in the internal force of the rod and the overall deformation of the tower. Therefore, appropriate indicators are selected from the two aspects of the yield degree of the rod and the overall inclination degree of the tower, that is, the equivalent stress and the center displacement of the tower top are selected as the failure indicators of the transmission tower.

[0250] For the plastic material such as the angle steel of the transmission tower, no matter what stress state the rod is in, when its distortion energy density reaches the distortion energy density of the material when it yields in uniaxial tension, the rod will yield and fail. This strength theory is called the VonMises criterion, and the corresponding strength judgment calculation formula is:

[0251]

[0252] Where: eq is the Von Mises equivalent stress (MPa); σ1, σ2, and σ3 are the first principal stress, the second principal stress, and the third principal stress (MPa), respectively; σ is the allowable stress of the material (MPa). In this study, the yield stress of the rod material is taken. As the internal force of the rod increases, when the equivalent stress exceeds the yield stress of the rod, the rod can be considered to have failed.

[0253] The specific failure criteria are as follows:

[0254] The main material or the diagonal material yields in its entire section, and the equivalent stress reaches the yield strength of the main material or the diagonal material. The yield strengths of the main material and the diagonal material are 345MPa and 235MPa respectively. When either the main material or the diagonal material yields, the transmission tower is considered to have failed.

[0255] According to Article 5.1.4 of the DLT 741-2019 Overhead Transmission Line Operation Regulations, the inclination of transmission towers below 50m must be less than 1% of the tower height. The total height of the combined tower is 26.2m, so the maximum allowable displacement of the center of the tower top is 262mm.

[0256] Use the field survey and transmission tower design data to establish a transmission tower numerical model, and complete the transmission tower numerical simulation in ANSYS;

[0257] The coordinate system in ANSYS is consistent with that in FLAC3D, and the output results in FLAC3D are used as the input results of each tower foot in ANSYS;

[0258] Among them, the ANSYS numerical simulation results are analyzed to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide. The specific steps are as follows:

[0259] The internal force cloud map, displacement cloud map, equivalent stress cloud map and failure index of the transmission tower are analyzed. The internal force cloud map of the transmission tower is characterized by axial force, shear force, bending moment and torque. The main material below the first section of the transverse diaphragm is mainly compressed, and the order of axial force is: main material 3>main material 4>main material 2>main material 1; the diagonal material below the first section of the transverse diaphragm is mainly tensile, and the axial force is mainly concentrated between the tower feet 3 and 4, and on the diagonal material between the tower feet 1 and 2. Shear force, bending moment and torque are all concentrated on the main material, and the positions of the maximum values ​​of the three are roughly the same; the shear force, bending moment and torque on the main material 4 are the largest, and the shear force, bending moment and torque on the main material 2 are the second largest. The equivalent stress is concentrated on the diagonal material between the tower feet 3 and 4, and between the tower feet 1 and 2. The maximum displacement of the tower occurs at the top of the tower, and the overall displacement trend is that the displacement gradually increases from bottom to top, and the displacement of the rods close to the tower foot 4 on the same horizontal plane is larger. In summary, it can be seen that the transmission tower yields first on the slope.

[0260] By comparing the relationship between the two failure indicators and the maximum relative displacement of the tower foot ( Fig.12 , 13 ), obtain the corresponding relationship between the actual deformation failure of the transmission tower and the failure criterion, that is, the failure mechanism of the transmission tower is obtained ( Fig.14 ). Under the action of the landslide, the tower undergoes double foundation deformation, relative displacement occurs between the four tower feet, and the poles are deformed, mainly in the main material and the diagonal material. According to the simulation results, the failure mode of the transmission tower is the yielding of the diagonal material, which leads to the failure of the tower.

[0261] S300: The FLAC3D-Monte Carlo method is used to calculate the probability of landslide instability under different rainfall conditions, and the annual probability of landslide instability under the corresponding conditions is calculated. The annual probability of landslide instability is used to represent the danger of landslide.

[0262] S301: The FLAC3D-Monte Carlo method is used to calculate the probability of landslide instability under different rainfall conditions. The following steps can be used:

[0263] The FLAC3D-Monte Carlo method is used to calculate the landslide instability probability, and then the annual landslide instability probability is calculated;

[0264] The annual landslide instability probability is calculated based on the conversion formula between the landslide instability probability and the annual landslide instability probability.

[0265] The specific steps of using the FLAC3D-Monte Carlo method to calculate the landslide instability probability and then calculating the annual landslide instability probability include the following:

[0266] The FLAC3D-Monte Carlo method is a method that integrates the idea of ​​Monte Carlo random numbers into the FLAC3D numerical calculation model. The calculation steps are as follows;

[0267] Selection and processing of random variables: Among the various geotechnical parameters that affect the stability of the landslide, the parameters that have the greatest impact on the reliability analysis results are selected, generally the cohesion c and internal friction angle of the soil. So choose c, As random variables, N sets of random numbers are generated in computer language;

[0268] The initial geostress field is obtained according to the FLAC3D solution process and the constructed three-dimensional geological body numerical model;

[0269] The selection and processing of random variables in N groups of random numbers c, Substituting into the corresponding N groups of safety factors, this time we choose c, As random variables, other material parameters remain constant;

[0270] Statistics and analysis are performed on N groups of safety factors to calculate the failure probability of the slope;

[0271] Based on the three-dimensional geological body numerical model established by FLAC3D in S2-1 above, the working conditions and rock and soil parameters are changed, and the other parameters remain unchanged. At the same time, the rainfall intensity and infiltration depth under different return periods are calculated. The rainfall intensity is calculated according to the rainfall intensity formula with different return periods in the working condition, and the infiltration depth is calculated according to the formula of the non-waterlogging infiltration part. Substitute them into the formula to obtain the probability of landslide instability under different rainfall conditions.

[0272] Based on the three-dimensional geological body numerical model established by FLAC3D in S2-1 above, the working conditions and rock and soil parameters are changed, and the others remain unchanged. At the same time, the rainfall intensity and infiltration depth under different recurrence periods are calculated, where the rainfall intensity is calculated according to formula (Formula 1) and the infiltration depth is calculated according to formula (Formula 2). The calculation conditions are shown in Table 3, and the probability of landslide instability under different rainfall conditions is obtained by substitution.

[0273] Table 3 Calculation conditions

[0274]

[0275] The calculation of the annual landslide instability probability according to the conversion formula between the landslide instability probability and the annual landslide instability probability may specifically include the following steps:

[0276] The possibility of landslide instability under different working conditions should take into account the probability of the landslide itself sliding, as well as the randomness and uncertainty of the inducing factors, that is, the determination of the annual probability of landslide instability is determined by the common probability of the two. When rainfall is the inducing factor, extreme rainfall events can be regarded as event A, and landslide instability can be regarded as event B. The expression of the annual probability of landslide instability Р is:

[0277] P=P[A]P[B / A]

[0278] Where: P is the annual probability of landslide instability; P[A] is the probability of extreme rainfall events; P[B / A] is the probability of landslide instability under extreme rainfall conditions;

[0279] The probability of landslide instability under extreme rainfall conditions (P[B / A]) can be calculated by the FLAC3D-Monte Carlo method; the probability of extreme rainfall events (P[A]) is the inverse of the return period of extreme rainfall, so the annual probability of landslide instability under extreme rainfall is;

[0280] P=P[B / A] / T

[0281] Where: P is the annual probability of landslide instability; P[B / A] is the probability of landslide instability under extreme rainfall conditions; T is the rainfall return period (a);

[0282] The obtained landslide instability probability is converted into the annual landslide instability probability of the corresponding working condition.

[0283] S400: Establish a vulnerability assessment model for transmission towers under landslides based on the failure model of transmission towers;

[0284] S401: Establishing a vulnerability assessment model of transmission towers under landslide based on the failure model of transmission towers, which specifically includes the following steps:

[0285] According to the above numerical simulation, the only failure criterion that meets the transmission tower is found, that is, the failure mode of the transmission tower is determined according to the numerical simulation results. The failure modes of the transmission tower include oblique material failure, main material failure, and overall tilt failure.

[0286] A transmission tower vulnerability assessment model is proposed based on the transmission tower failure model;

[0287] Obtain the vulnerability value of transmission towers under different rainfall conditions;

[0288] Among them, a transmission tower vulnerability assessment model is proposed based on the transmission tower failure model, which may include the following steps:

[0289] According to the failure mode of transmission towers, when the maximum relative displacement of the tower foot is 52.89 mm and the equivalent stress of the diagonal material reaches 235 MPa, it is considered to be a failure; find the corresponding failure threshold and the corresponding maximum relative displacement threshold of the tower foot;

[0290] According to the relationship between the actual maximum relative displacement of the tower foot and the maximum relative displacement of the tower foot, the transmission tower vulnerability assessment model is established as follows;

[0291]

[0292] Where: V is the vulnerability value; Δx 实际 is the maximum relative displacement of the tower foot (mm), which is the composite displacement of the maximum relative displacement of the tower foot in the X direction and the maximum relative displacement in the Z direction. Its calculation formula is shown in the calculation formula of the maximum relative displacement of the tower foot;

[0293] When Δx 实际 Less than the maximum allowable value Δx 阈值 When , the vulnerability value is the ratio of its actual value to the maximum allowed value;

[0294] When Δx 实际 Greater than or equal to the maximum allowable value Δx 阈值 When the tower is considered to have completely failed, in this example, Δx 阈值 It is 52.89mm.

[0295] Therefore, the vulnerability value is 1 at this time.

[0296] S500: Based on the landslide hazard assessment and transmission tower vulnerability assessment, the “risk = hazard × vulnerability × economic value” model is used to complete the transmission tower landslide risk assessment.

[0297] S501: Based on the landslide hazard assessment and transmission tower vulnerability assessment, it specifically includes the following steps:

[0298] Risk refers to the economic losses, life losses and environmental damage losses caused by the disaster process that various types of hazard-bearing bodies may encounter under certain conditions and within a certain period of time, that is, risk = hazard × vulnerability; according to the basic definition of risk, risk should include hazard, vulnerability of landslide hazard-bearing bodies and the number or value of hazard-bearing bodies; the specific calculation expression of risk is;

[0299] R=H×V×E

[0300] Where R is the landslide risk; H is the landslide hazard, expressed as the annual probability of landslide instability; V is the vulnerability of the transmission tower; E is the value of the transmission tower;

[0301] Obtain the value of the transmission tower according to the design data of the transmission tower;

[0302] According to the design data of the transmission tower, the value of the transmission tower is obtained, see Table 4;

[0303] Table 4 Transmission Tower Material List

[0304]

[0305] The annual risk values ​​of transmission tower landslides under different rainfall conditions are obtained and are shown in Table 5.

[0306] Table 5 Economic loss risk of transmission towers under different working conditions

[0307] Working conditions T(a) H V E(10,000 yuan) R (ten thousand yuan) Condition 1 10 0.00775 0.51 62.6772 0.248 Condition 2 20 0.01003 0.68 62.6772 0.427 Condition 3 50 0.00715 0.85 62.6772 0.381 Condition 4 100 0.00524 1 62.6772 0.328

[0308] Through the above step S500, the landslide risk assessment result based on the transmission tower failure model of the embodiment can be obtained. The present invention reasonably considers the deformation relationship between the landslide and the transmission tower, has a simple operation process, and has good feasibility. The transmission tower landslide risk assessment result can provide theoretical and methodological support for the geological disaster risk management and control of mountain power grid facilities.

[0309] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A landslide disaster risk assessment method based on a transmission tower failure model, characterized in that: include, Conduct detailed surveys of the landslide area to identify the engineering geological conditions, deformation characteristics of the landslide, and deformation characteristics of the transmission towers, derive the landslide deformation failure mode and deformation stage, and obtain the deformation relationship between the transmission towers and the ground surface; Conduct surveys in the landslide area and obtain the physical and mechanical parameters of the rock and soil through field and indoor tests; use FLAC3D and ANAYS numerical simulation software to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide sliding, and verify the numerical simulation results with field monitoring data; The FLAC3D-Monte Carlo method is used to calculate the probability of landslide instability under different rainfall conditions, and the annual probability of landslide instability under the corresponding conditions is calculated. The annual probability of landslide instability is used to represent the danger of landslide. Based on the failure model of transmission towers, a vulnerability assessment model of transmission towers under landslides is established; Based on the landslide hazard assessment and transmission tower vulnerability assessment, the "risk = hazard × vulnerability × economic value" model is used to complete the transmission tower landslide risk assessment.

2. The landslide disaster risk assessment method based on the transmission tower failure model according to claim 1 is characterized in that: The survey of the landslide area to identify the engineering geological conditions of the landslide area, the deformation characteristics of the landslide, and the deformation characteristics of the transmission tower can be specifically carried out in the following steps: Conduct surveys in the landslide area to identify the engineering geological conditions, deformation characteristics of the landslide, and deformation characteristics of the transmission towers, and obtain recent on-site monitoring data of the transmission towers and the ground surface; According to the on-site monitoring data and rainfall data, it is concluded that rainfall is the main inducing factor; Based on the results of the field investigation and combined with the field monitoring data, the deformation failure mode and deformation stage of the landslide were obtained; Based on the field investigation results and combined with the field monitoring data, the deformation relationship between the transmission tower and the ground surface is obtained.

3. The landslide disaster risk assessment method based on the transmission tower failure model according to claim 2 is characterized in that: The FLAC3D-Monte Carlo method is used to calculate the landslide instability probability under different rainfall conditions, and the annual landslide instability probability under the corresponding conditions is calculated. The danger of the landslide is expressed by the annual landslide instability probability. The specific steps are as follows: Conduct surveys on the landslide area, obtain the physical and mechanical parameters of the rock and soil through field and indoor tests, build a three-dimensional geological model and numerical model of the landslide, and complete the numerical simulation of landslide deformation based on FLAC3D numerical simulation software; Collect the design data of transmission towers, obtain the material parameters of the poles, build a numerical model of the transmission towers, and complete the numerical simulation of the deformation and failure of the transmission towers based on ANSYS numerical simulation software; Analyze the ANSYS numerical simulation results to obtain the deformation failure model and mechanism of transmission towers under landslides; The survey of the landslide area and obtaining the physical and mechanical parameters of the rock and soil through field tests and indoor tests include the following steps: The steps for field testing can be as follows: During the on-site investigation, the remote sensing image data of the site was obtained using the UAV 3D oblique photography technology, and the point cloud data and preliminary contour lines were generated through Pix4dMapper; The generated point cloud data and preliminary contour lines are processed in GlobalMapper to obtain processed contour lines; The processed contour lines are brought into Rhino software to establish a three-dimensional geological model, and a three-dimensional numerical model of the landslide is established according to the development characteristics of the landslide; The natural working condition and the extreme rainfall working condition are selected as the calculation working conditions. The natural working condition is used to verify with the actual monitoring data, and the extreme rainfall condition is used to obtain the whole process of deformation and failure of the transmission tower under the action of landslide sliding. The rainfall intensity under different return periods is calculated according to the rainstorm intensity formula in the "New Generation Rainstorm Intensity Formula for Chinese Cities" to determine the rainfall intensity under different return periods in the calculation conditions. The calculation formula is as follows: Where: i is the rainfall intensity; T is the rainfall return period; t is the rainfall duration; The modified Green-Ampt model used this time assumes that the soil at different depths has the same initial moisture content before infiltration. During infiltration, there is a wetting front in the soil layer, which divides the soil into saturated and unsaturated areas. The infiltration depth corresponding to different rainfall intensities in the calculation conditions is determined according to the modified Green-Ampt model. The formula for the non-waterlogging infiltration part is as follows: Where: y is the infiltration depth; t is the rainfall duration; q is the rainfall intensity; is the slope gradient, is the saturated water content; is the initial water content; The displacements of the four tower feet of the transmission tower at the surface projection are monitored separately, and the landslide stability division is constructed according to the analysis of the numerical simulation results. The displacements of the monitoring points are simulated and used as the displacements of the tower feet and as the input conditions for the subsequent numerical simulation of the transmission tower.

4. The landslide disaster risk assessment method based on the transmission tower failure model according to claim 3 is characterized in that: The design data of the transmission tower is collected to obtain the material parameters of the pole, a numerical model of the transmission tower is constructed, and the deformation failure numerical simulation of the transmission tower is completed based on the ANSYS numerical simulation software. Specifically, the following steps can be adopted: The failure criterion of the transmission tower is established, and the maximum relative displacement of the tower foot is defined. The maximum relative displacement of the tower foot is characterized by calculating the relative displacement of the maximum tower foot displacement and the minimum tower foot displacement in the X and Z directions in the corresponding directions, and then vectorizing the relative displacements in the X and Z directions. The calculation formula for the maximum relative displacement of the tower foot is as follows: Where: Δx is the maximum relative displacement of the tower foot (mm); x1 is the displacement value of the tower foot with the largest displacement in the X direction; x2 is the displacement value of the tower foot with the smallest displacement in the X direction; z1 is the displacement value of the tower foot with the largest displacement in the Z direction; z2 is the displacement value of the tower foot with the smallest displacement in the Z direction; The landslide deformation results in an increase in the maximum relative displacement of the tower foot, which causes an increase in the internal force of the rod and the overall deformation of the tower. According to the yield degree of the rod and the overall inclination degree of the tower, appropriate failure indicators of the transmission tower are selected. The failure indicators of the transmission tower are equivalent stress and the center displacement of the tower top. The transmission tower angle steel is made of plastic material. The yield degree of the rod is characterized by the rod being in a stress state. When the distortion energy density of the rod reaches the distortion energy density of the plastic material when it yields in uniaxial tension, the rod yields and fails. This strength theory is called the Von Mises criterion. The corresponding strength judgment calculation formula is: Where: eq is the Von Mises equivalent stress (MPa); σ1, σ2, and σ3 are the first principal stress, the second principal stress, and the third principal stress (MPa), respectively; σ is the allowable stress of the material (MPa). In this study, the yield stress of the rod material is taken. As the internal force of the rod increases, when the equivalent stress exceeds the yield stress of the rod, the rod fails; The specific failure criteria are as follows: The main material or the diagonal material yields in its entire section, and the equivalent stress reaches the yield strength of the main material or the diagonal material. The yield strengths of the main material and the diagonal material are 345MPa and 235MPa respectively. When either the main material or the diagonal material yields, the transmission tower is considered to have failed. According to Article 5.1.4 of the specification "DLT 741-2019 Overhead Transmission Line Operation Regulations", the inclination of transmission towers below 50m must be less than 1% of the tower height; Use the field survey and transmission tower design data to establish a transmission tower numerical model, and complete the transmission tower numerical simulation in ANSYS; The coordinate system in ANSYS is consistent with that in FLAC3D, and the output results in FLAC3D are used as the input results of each tower foot in ANSYS; The analysis of ANSYS numerical simulation results to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide can be carried out in the following steps: Analyze the internal force cloud map, displacement cloud map, equivalent stress cloud map, and failure index of the transmission tower, wherein the internal force cloud map of the transmission tower is characterized by axial force, shear force, bending moment, and torque; By comparing the relationship between the two failure indicators and the maximum relative displacement of the tower foot, the corresponding relationship between the actual deformation failure of the transmission tower and the failure criterion is obtained, that is, the failure mechanism of the transmission tower is obtained.

5. The landslide disaster risk assessment method based on the transmission tower failure model according to claim 4 is characterized in that: The FLAC3D-Monte Carlo method is used to calculate the probability of landslide instability under different rainfall conditions, and the following steps can be used: The FLAC3D-Monte Carlo method is used to calculate the probability of landslide instability and the annual probability of landslide instability is calculated; The annual landslide instability probability is calculated based on the conversion formula between the landslide instability probability and the annual landslide instability probability. The method of calculating the landslide instability probability by using the FLAC3D-Monte Carlo method to calculate the annual landslide instability probability may specifically include the following steps: FLAC3D-Monte Carlo method characterizes the method of integrating Monte Carlo random numbers into the FLAC3D numerical calculation model. The calculation steps are as follows; Selection and processing of random variables: Among the various geotechnical parameters that affect the stability of the landslide, the parameters that have the greatest impact on the reliability analysis results are selected, which are generally the cohesion and internal friction angle of the soil. Therefore, cohesion and internal friction angle are selected as random variables, and N groups of random numbers are generated in the computer language; The initial geostress field is obtained according to the FLAC3D solution process and the constructed three-dimensional geological body numerical model; Substitute the N groups of random numbers of cohesion and internal friction angle in the selection and processing of random variables to obtain the corresponding N groups of safety factors; Statistics and analysis are performed on N groups of safety factors to calculate the failure probability of the slope; Based on the three-dimensional geological body numerical model established by FLAC3D, the working conditions and rock and soil parameters are changed, and other parameters remain unchanged. The rainfall intensity and infiltration depth under different recurrence periods are calculated. The rainfall intensity and infiltration depth are calculated according to the formula given above, and the probability of landslide instability under different rainfall conditions is obtained by substituting them into the formula. The step of calculating the annual landslide instability probability according to the conversion formula between the landslide instability probability and the annual landslide instability probability may specifically include the following steps: The instability of landslides under different working conditions includes the probability of sliding of the landslide itself, the randomness and uncertainty of the inducing factors, and the determination of the annual instability probability of landslides is determined by the possibility of the two occurring together; When rainfall is the triggering factor, the extreme rainfall event is regarded as event A and the landslide instability is regarded as event B. The annual probability expression of landslide instability is: P=P[A]P[B / A] Where: P is the annual probability of landslide instability; P[A] is the probability of extreme rainfall events; P[B / A] is the probability of landslide instability under extreme rainfall conditions; The probability of landslide instability under extreme rainfall conditions is calculated by the FLAC3D-Monte Carlo method. The probability of extreme rainfall events is the inverse of the return period of extreme rainfall, so the annual probability of landslide instability under extreme rainfall is expressed as: P=P[B / A] / T Where: P is the annual probability of landslide instability; P[B / A] is the probability of landslide instability under extreme rainfall conditions; T is the rainfall return period (a); The obtained landslide instability probability is converted into the annual landslide instability probability of the corresponding working condition.

6. The landslide disaster risk assessment method based on the transmission tower failure model according to claim 5 is characterized in that: The vulnerability assessment model of the transmission tower under the action of landslide is established based on the failure model of the transmission tower, which specifically includes the following steps: According to the above numerical simulation, the only failure criterion that meets the transmission tower is found, and the failure mode of the transmission tower is determined according to the numerical simulation results. The failure modes of the transmission tower include failure of oblique material, failure of main material, and overall tilt failure. A transmission tower vulnerability assessment model is proposed based on the transmission tower failure model; Obtain the vulnerability value of transmission towers under different rainfall conditions; The proposed transmission tower vulnerability assessment model based on the transmission tower failure model may specifically include the following steps: According to the failure mode of the transmission tower, the corresponding failure threshold and the corresponding maximum relative displacement threshold of the tower foot are obtained; According to the relationship between the actual maximum relative displacement of the tower foot and the maximum relative displacement of the tower foot, the expression of the transmission tower vulnerability evaluation model is as follows: Where: V is the vulnerability value; Δx 实际 is the maximum relative displacement of the tower foot (mm), which is the composite displacement of the maximum relative displacement of the tower foot in the X direction and the maximum relative displacement in the Z direction. Its calculation formula is shown in the calculation formula of the maximum relative displacement of the tower foot; When Δx 实际 Less than the maximum allowable value Δx 阈值 When , the vulnerability value is the ratio of its actual value to the maximum allowed value; When Δx 实际 Greater than or equal to the maximum allowable value Δx 阈值 When the tower has completely failed, Therefore, the vulnerability value is 1 at this time.

7. The landslide disaster risk assessment method based on the transmission tower failure model according to claim 6 is characterized in that: The landslide hazard assessment and transmission tower vulnerability assessment specifically include the following steps: The risk is characterized by the economic losses, life losses and environmental damage losses caused by disasters in various disaster-prone bodies under certain conditions and within a certain period of time, that is, risk degree = hazard degree × vulnerability degree; According to the basic definition of risk, the risk includes the danger, vulnerability of the landslide disaster-bearing body, the number of disaster-bearing bodies, and the value of the transmission tower; the specific calculation expression of risk is; R=H×V×E Where R is the landslide risk; H is the landslide hazard, expressed as the annual probability of landslide instability; V is the vulnerability of the transmission tower; E is the value of the transmission tower; Obtain the value of the transmission tower according to the design data of the transmission tower; The annual risk value of transmission tower landslide under different rainfall conditions is obtained.

8. A landslide disaster risk assessment system based on a transmission tower failure model, based on the landslide disaster risk assessment method based on a transmission tower failure model according to any one of claims 1 to 7, characterized in that: Also includes, The acquisition module conducts a detailed survey of the landslide area, identifies the engineering geological conditions of the landslide area, the deformation characteristics of the landslide, and the deformation characteristics of the transmission tower, derives the landslide deformation failure mode and deformation stage, and obtains the deformation relationship between the transmission tower and the ground surface; Verification module: survey the landslide area and obtain the physical and mechanical parameters of the rock and soil through field and indoor tests; use FLAC3D and ANAYS numerical simulation software to obtain the deformation failure model and mechanism of the transmission tower under the action of landslide sliding, and verify the numerical simulation results with field monitoring data; The calculation module uses the FLAC3D-Monte Carlo method to calculate the probability of landslide instability under different rainfall conditions, and calculates the annual probability of landslide instability under the corresponding conditions, and uses the annual probability of landslide instability to represent the danger of the landslide; Building module, based on the failure model of transmission tower, establishes the vulnerability assessment model of transmission tower under landslide; The evaluation module, based on the landslide hazard assessment and transmission tower vulnerability assessment, adopts the "risk = hazard × vulnerability × economic value" model to complete the transmission tower landslide risk assessment.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the landslide disaster risk assessment method based on the transmission tower failure model described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the landslide disaster risk assessment method based on the transmission tower failure model described in any one of claims 1 to 7 are implemented.

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