A method for quantifying avalanche impact damage energy on power transmission towers

Abstract

This invention discloses a method for quantifying the impact damage energy of avalanches on transmission towers, relating to the field of avalanche disaster assessment technology. The method includes: acquiring the DEM, slope distribution, and initial snow source conditions of the slope where the target tower is located, and completing avalanche dynamic simulation; setting a virtual control section upstream on the snow-facing side to extract free-field time-varying flow field parameters and determine the flow regime type, thus obtaining a control section parameter set; mapping the control section parameter set to the snow-facing / snow-repellent surfaces of the tower, and introducing lattice transmission, dynamic blockage, and group shielding corrections to form the time history of the total incident kinetic energy intercepted by the structure. This invention integrates the free-field time-varying flow field parameters, flow regime identification codes, and the time-varying effective force-bearing area and residual velocity on the snow-facing / snow-repellent surfaces of the tower into an energy conservation framework, forming a closed-loop quantitative link of the total incident kinetic energy intercepted by the structure, the dissipated energy of the medium, and the additional potential energy, significantly reducing the energy deviation caused by fixed windward area, unilateral impact, and neglecting transmission shielding.

Description

Technical Field

[0001] This invention relates to the field of avalanche disaster assessment technology, and in particular to a method for quantifying the impact damage energy of an avalanche on a power transmission tower. Background Technology

[0002] In recent years, the fields of avalanche disaster assessment and power transmission corridor disaster prevention have gradually shifted from empirical criteria to numerical methods that couple "topography-flow-structure". Conventional technical approaches typically construct avalanche simulation calculation grids based on the DEM and slope distribution of the slope where the target tower is located, use unsteady shallow water wave equations with depth integration to describe the evolution of the velocity field and flow depth field, and extract time-varying flow field parameters at typical cross-sections. On the structural side, incident kinetic energy or impact power is often calculated using the equivalent windward area and drag coefficient of the snow-facing surface, and structural load-bearing capacity verification and risk classification are achieved in conjunction with finite element stability assessment.

[0003] Existing technologies often suffer from an incomplete energy chain when converting free-field simulation results into "effective disaster-causing energy for towers": On the one hand, the lattice transmission, dynamic blockage, and group shielding of the snow-facing / snow-repelling surfaces cause significant time-varying changes in the effective force-bearing area and residual velocity. If a fixed windward area and unilateral impact assumption are still used, the time history of the total kinetic energy intercepted by the structure is easily distorted. On the other hand, the compaction plastic deformation, particle breakage, and wet-sticky snow pressure-melting phase transition of the snow medium during the impact contact process consume a large amount of non-disaster-causing internal energy. If the medium dissipation is not deducted and the additional potential energy contribution caused by the stagnation and accumulation in front of the tower and the climbing along the tower is not further taken into account, it is difficult to obtain the effective disaster-causing energy time history and stability classification results that can be used for engineering early warning. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a method for quantifying the impact damage energy of avalanches on transmission towers, which solves the problem of the incomplete closure of the conversion of the time-varying flow state of avalanches into the effective disaster-causing energy of the tower, making it difficult to support stability assessment and early warning classification.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] This invention provides a method for quantifying the impact damage energy of avalanches on transmission towers, which includes: acquiring the DEM, slope distribution and initial conditions of the snow source of the slope where the target tower is located and completing the dynamic simulation of the avalanche; setting up a virtual control section upstream on the snow-facing side to extract free field time-varying flow field parameters and determine the flow regime type to obtain the control section parameter set;

[0008] The control section parameter set is mapped to the snow-facing / snow-repelling surface of the tower, and lattice transmission, dynamic blocking and group shading corrections are introduced to form the time history of the total incident kinetic energy intercepted by the structure.

[0009] The energy dissipation mechanism of snow medium compaction and crushing was used to quantify the total incident kinetic energy time history of the structure interception and deduct the non-hazardous internal energy loss to obtain the net impact kinetic energy time history and the medium dissipation energy time history.

[0010] The additional potential energy time history is obtained by quantifying the additional disaster-causing contribution of pre-tower stagnation and accumulation and the climbing effect along the tower based on the net impact kinetic energy time history.

[0011] The system summarizes the time histories of the total incident kinetic energy, the energy dissipated by the medium, and the additional potential energy, and completes the full time histories synthesis. Through finite element stability assessment of the tower and multi-level early warning determination, it outputs an effective disaster-causing energy quantification result package.

[0012] As a preferred embodiment of the method for quantifying the impact damage energy of avalanches on transmission towers as described in this invention, the step of obtaining the DEM, slope distribution, and initial snow source conditions of the slope where the target tower is located, and completing the avalanche dynamic simulation, specifically involves...

[0013] Read the DEM of the slope where the target tower is located and extract the slope aspect, slope and runoff path features, and summarize them to obtain the terrain raster parameter set;

[0014] The terrain raster parameter set is converted into an avalanche simulation calculation mesh, and the mesh resolution and boundary range are configured to generate the simulation scene mesh.

[0015] The initial conditions of the snow source are collected and its spatial distribution is mapped to the simulation scene mesh to obtain the initial field of the snow source; the initial conditions of the snow source include the initial density and water content;

[0016] The initial field of the snow source is solved by time progression, and the time history evolution of the velocity field, flow depth field and density field is recorded to generate a set of simulation results for the avalanche free field.

[0017] As a preferred embodiment of the method for quantifying the impact damage energy of avalanches on transmission towers as described in this invention, the method for obtaining the control section parameter set specifically includes:

[0018] Within the avalanche free field simulation result set, a cross-sectional position intersecting with the tower axis is selected upstream along the snow-facing side to generate a virtual control cross-section.

[0019] Velocity, flow depth and evolution density are sampled at time intervals along the virtual control section and time-stamped to obtain the time-varying parameter sequence of the control section;

[0020] The dynamic Froude number is calculated based on the time-varying parameter sequence of the control section, and the water content in the initial conditions of the snow source is collected to form a two-parameter discrimination sequence.

[0021] Perform flow state type determination on the two-parameter discrimination sequence, generate flow state identification code, encapsulate the time-varying parameter sequence of the control section with the flow state identification code, and obtain the control section parameter set.

[0022] As a preferred embodiment of the method for quantifying the impact damage energy of avalanches on transmission towers as described in this invention, the mapping of the control section parameter set to the snow-facing / snow-repelling surface of the tower specifically involves:

[0023] Establish a geometric model of the digital twin of the transmission tower, divide it into micro-segments according to the height direction, and generate a list of tower micro-segments;

[0024] Based on the list of tower micro-segments, spatial identifiers for the snow-facing and snow-repelling surfaces are constructed, forming a surface identifier table;

[0025] The control section parameter set is projected onto the height micro-element corresponding to the action surface identification table according to the time series, and spatial interpolation is performed to obtain the time-varying parameter mapping sequence of the action surface;

[0026] The consistency of the time-varying parameter mapping sequence of the action surface with the snow-facing and snow-backing directions is checked, and the flow field mapping sequence package of the action surface is generated.

[0027] As a preferred embodiment of the method for quantifying the impact damage energy of avalanches on transmission towers as described in this invention, the time history of the total incident kinetic energy intercepted by the forming structure is specifically as follows:

[0028] The projected area of ​​the truss components on the snow-facing surface is extracted from the flow field mapping sequence of the action surface, and the contour envelope area is calculated to obtain the geometric feature sequence of the snow-facing surface.

[0029] The geometric feature sequence of the snow-facing surface is associated with the flow regime identification code and the blockage coefficient is updated so that the effective force-bearing area of ​​the snow-facing surface changes adaptively with time, forming the effective force-bearing area time history.

[0030] A group shading attenuation correction was applied to the residual velocity on the snow-covered side to form a snow-facing / snow-covered velocity field control sequence.

[0031] Based on the snow-facing / snow-backing velocity field comparison sequence, the incident power time histories of the snow-facing and snow-backing surfaces are calculated and time histories are integrated to obtain the total incident kinetic energy time histories of the structure.

[0032] As a preferred embodiment of the method for quantifying the impact damage energy of avalanches on transmission towers as described in this invention, the energy dissipation mechanism of snow compaction and crushing refers to the mechanism by which energy is dissipated during the impact contact process of avalanche media due to compaction plastic deformation, particle crushing, and wet viscous snow pressure-melting phase transformation.

[0033] As a preferred embodiment of the method for quantifying the impact damage energy of avalanches on transmission towers as described in this invention, the method for obtaining the net impact kinetic energy time history and the medium dissipation energy time history specifically involves:

[0034] The impact velocity time history and effective force-bearing area time history of the total incident kinetic energy of the structural interception are extracted from the time history of the snow-facing surface to form an impact contact characteristic sequence.

[0035] By associating the impact contact characteristic sequence with the evolution density, water content, and flow regime identification code in the control section parameter set, an energy dissipation parameter sequence is obtained.

[0036] Based on the energy consumption parameter sequence, the energy consumption of compaction plasticity, crushing and compressive melting phase transformation are calculated separately, and summarized into the medium dissipation energy time history;

[0037] The time history of the medium dissipation energy is time-aligned with the time history of the total incident kinetic energy of the structure interception, and then subtraction is performed to obtain the net impact kinetic energy time history.

[0038] As a preferred embodiment of the method for quantifying the impact damage energy of avalanches on transmission towers as described in this invention, the method for obtaining the additional potential energy time history specifically involves:

[0039] The formation period of the stagnant accumulation zone in front of the tower was extracted from the net impact kinetic energy time history, and the accumulation range was marked to obtain the accumulation zone evolution record;

[0040] The evolution record of the accumulation zone is converted into a continuous static pressure distribution, and the potential energy contribution of the work done by the static pressure is calculated to generate the accumulation static pressure potential energy time history.

[0041] Identify the climbing stage along the tower corresponding to the net impact kinetic energy time history and extract the changes in climbing height and impact location to obtain the climbing evolution record;

[0042] The potential energy conversion and the contribution of eccentric overturning potential energy caused by lever arm lifting are calculated by climbing evolution records, and the climbing overturning potential energy time history is generated.

[0043] By merging the time history of accumulated static pressure potential energy with the time history of climbing and overturning potential energy, and keeping the time alignment, an additional potential energy time history is obtained.

[0044] As a preferred embodiment of the method for quantifying the impact damage energy of avalanches on transmission towers as described in this invention, wherein: the completion of full-time synthesis specifically involves,

[0045] The time histories of total incident kinetic energy, medium dissipated energy, and additional potential energy are resampled along a unified time axis to generate an aligned energy sequence.

[0046] The aligned energy sequence is aggregated according to the energy conservation relationship to form an effective disaster-causing energy time history;

[0047] The contribution rate of energy components is statistically analyzed on the time history of effective disaster-causing energy to obtain a set of effective disaster-causing energy synthesis results.

[0048] As a preferred embodiment of the method for quantifying the impact damage energy of avalanches on transmission towers as described in this invention, the output of the effective disaster-causing energy quantification result package specifically includes:

[0049] Establish a finite element model of the transmission tower, configure material parameters, boundary constraints and key component connection relationships, and generate a finite element model package for the tower;

[0050] The effective disaster-causing energy synthesis result set is associated with the tower finite element model package, and the ultimate strain energy that the tower can bear is calculated to obtain the structural ultimate energy benchmark.

[0051] The effective disaster-causing energy time history is compared with the structural limit energy benchmark in a graded manner to generate multi-level early warning results;

[0052] The multi-level early warning results are combined with the effective disaster-causing energy synthesis result set, which is then packaged and archived to output the effective disaster-causing energy quantification result package.

[0053] The beneficial effects of this invention are as follows: By unifying the free-field time-varying flow field parameters, flow regime identification codes, and the time-varying effective force-bearing area and residual velocity on the snow-facing / snow-repelling surfaces of the tower into the energy conservation framework, a closed-loop quantitative link is formed for the total incident kinetic energy of structural interception, the energy dissipated by the medium, and the additional potential energy. This significantly reduces the energy deviation caused by fixed windward area, unilateral impact, and neglecting transmission shielding. Based on the energy dissipation mechanism of snow medium compaction and crushing, the non-disaster-causing internal energy loss caused by compaction plastic deformation, particle crushing, and wet sticky snow compressive melting phase change is explicitly deducted, making the contribution boundaries of net impact kinetic energy and additional potential energy clear, and improving the physical consistency and interpretability of the effective disaster-causing energy time history. After the effective disaster-causing energy quantification results are connected with the finite element stability assessment of transmission towers, a structural limit energy benchmark can be obtained and multi-level early warning judgment can be realized, thereby improving the reliability of risk classification, reducing false alarms and missed alarms, and providing a unified quantitative basis for protection design and operation and maintenance decisions under different flow regime conditions. Attached Figure Description

[0054] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a flowchart illustrating a method for quantifying the impact energy of an avalanche on a transmission tower.

[0056] Figure 2 A schematic diagram of the physical model of avalanche fluid impacting a power transmission tower.

[0057] Figure 3This is a full-time energy component evolution curve for avalanche flow pressure impact-type failure and post-peak static pressure accumulation-type failure. Detailed Implementation

[0058] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0059] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0060] 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 phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0061] Reference Figures 1-3 As one embodiment of the present invention, this embodiment provides a method for quantifying the impact damage energy of an avalanche on a transmission tower, comprising the following steps:

[0062] S1. Obtain the DEM, slope distribution and initial conditions of the snow source of the slope where the target tower is located, and complete the avalanche dynamic simulation. Set up a virtual control section upstream on the snow-facing side to extract the free field time-varying flow field parameters and determine the flow regime type to obtain the control section parameter set.

[0063] Read the DEM (Digital Elevation Model) of the slope where the target tower is located and extract the slope aspect, slope gradient and confluence path features to obtain the terrain raster parameter set.

[0064] The terrain raster parameter set is converted into an avalanche simulation calculation mesh, and the mesh resolution is configured to 5m (selectable range 2m to 10m). The mesh resolution is determined based on the terrain analysis requirements of the confluence path and abrupt slope changes, as well as the numerical stability requirements of the unsteady shallow water wave equation (SWE) of depth integral. The boundary range is configured to cover the initial field of the snow source and extend 200m to 500m upstream along the main confluence path, cover 300m to 800m downstream of the target tower downstream, and extend 200m to 500m laterally to both sides of the centerline of the main confluence path. The boundary range is determined based on the requirements of sufficient flow field development after snow release, outflow boundary reflection suppression, and lateral confluence coverage. The simulation scene mesh is then generated.

[0065] The initial conditions of the snow source are collected and the spatial distribution is mapped to the simulation scene mesh to obtain the initial field of the snow source. The initial conditions of the snow source include the initial density and water content.

[0066] After obtaining the initial field of the snow source, a time-progression solution is performed on the initial field to obtain the time-history evolution of the free field velocity field, flow depth field, and density field. To ensure that the simulation solution physically satisfies mass and momentum conservation, the time-progression solution uses the unsteady shallow water wave equation (SWE) of depth integral to update the two-dimensional flow field, as follows:

[0067] ;

[0068] in, Indicates flow depth (equivalent water depth / thickness of avalanche fluid); Indicates time; It represents the horizontal two-dimensional coordinate axes (along two orthogonal directions of the terrain grid) and defines the spatial discretization and partial derivative directions; it is used to obtain the spatial distribution of velocity, current depth, and density. They are respectively direction, The depth-averaged velocity component in the direction; Represents gravitational acceleration; Indicates the slope angle (overall slope angle); Indicates the slope angle at , Component of direction; This indicates the resistance acting at the bottom of the snow layer. , Component of direction; This represents the avalanche fluid density (which can be instantaneous or localized). The resistance acting at the bottom of the snow layer is represented by the Voellmy-Salm rheological model to reflect the unique frictional energy dissipation characteristics of avalanche fluids. Specifically:

[0069] ;

[0070] in, Indicates the coefficient of dry friction (Coulomb friction), which dominates the accumulation and stopping phases; It represents the turbulence coefficient, which dominates the high-speed flow stage.

[0071] To explicitly incorporate the compaction effect from the simulation into the density field and output an evolved density usable for subsequent energy links, the cross-sectional density is updated at each time step based on the vertical compressive stress, and the updated cross-sectional density is written into the density field time history evolution; the evolution expression for the cross-sectional density is as follows:

[0072] ;

[0073] in, Indicates cross-sectional density as a function of time The evolution value of the change; Indicates the initial density; This represents the maximum compacted density / final compacted density, which can be determined by experiment or inversion, and satisfies the following conditions: , Represents ice density; Represents an exponential function; This represents the vertical compressive stress (which varies with time). For integration variables; For time infinitesimal elements; It represents the volumetric compressibility modulus (equivalent volumetric compaction stiffness).

[0074] To further explain, in order to ensure The value is consistent with the flow stage. When accumulation is significant, static pressure dominates, so the value is:

[0075] ;

[0076] in, Flow depth / accumulation height (can be obtained from cross-sectional flow depth or tower front accumulation model); This represents the static pressure correction factor (considering lateral constraints, arch effect, etc., and can be taken from an empirical range).

[0077] When the impact is significant, static pressure and dynamic pressure coupling are used, and the following is taken:

[0078] ;

[0079] in, Indicates the dynamic pressure / impact coupling coefficient; This indicates the velocity in front of the tower or the local velocity in front of the tower.

[0080] The bulk modulus of snow is related to its moisture content; as the moisture content increases, the snow is more easily compacted, which is equivalent to... It then decreased. The calculation expression is:

[0081] ;

[0082] in, Indicates the reference volumetric compressibility modulus; Indicates the reference density; It represents the density exponent (power exponent), which adjusts the sensitivity of density to modulus amplification; This represents the moisture content sensitivity coefficient / influence strength coefficient, indicating the strength of the effect of adjusting the moisture content on the decrease in equivalent compaction stiffness. It is obtained by fitting the compaction test (compression test / impact compaction test at different moisture contents). Indicates the snow source at any time To accurately capture the flow regime characteristics, the time-varying moisture content is calculated using the thermodynamic phase transition equation:

[0083] ;

[0084] in, Indicates moisture content, Indicates the latent heat of fusion of ice. It represents the rate of heat generation from frictional dissipation (the rate at which energy is dissipated and converted into heat).

[0085] To further explain, the expression for the frictional dissipation acoustic-thermal efficiency is:

[0086] ;

[0087] in, The average velocity of the snow flow after integrating over the entire flow depth is expressed as:

[0088] ;

[0089] in, Depth coordinates are Local velocity (velocity profile function) at a given location.

[0090] A virtual control section is generated by selecting a cross-sectional position that intersects with the tower axis upstream of the snow-facing side. The position of the virtual control section is set to 5 to 20 m upstream of the center axis of the snow-facing side of the transmission tower or 1 to 3 times the expected peak flow depth. The virtual control section is used to extract the time-varying parameters of the free field that are not disturbed by the tower.

[0091] Velocity, flow depth, and evolution density are sampled at each time step along the virtual control section and time-stamped to obtain a time-varying parameter sequence of the control section. The dynamic Froude number is calculated based on the time-varying parameter sequence of the control section, and the water content in the initial conditions of the snow source is collected to form a two-parameter discrimination sequence.

[0092] To further explain, the expression for calculating the dynamic Froude number is:

[0093] ;

[0094] in, The instantaneous Froude number represents the relative strength of inertial forces and gravitational effects, and is used to distinguish between supercritical and subcritical flow regimes.

[0095] The two-parameter discrimination sequence is subjected to flow regime type determination and a flow regime identifier code is generated. The flow regime type determination adopts a set of criteria for dry snow / supercritical flow, wet snow / viscous flow, and dense dry snow / subcritical flow, and the criterion terminology is kept consistent. The criteria are as follows:

[0096] Criterion A: Dry powder snow / supercritical flow: and (Preferred threshold) );

[0097] in, This represents the moisture content threshold, used to divide the flow regime into the first layer based on "wet sticky snow / non-wet sticky snow".

[0098] Physical basis: The snow body is dry and at a supercritical flow velocity, dominated by inertial force, and the snow particles have high dispersion.

[0099] Criterion B: Wet snow / viscous flow: ;

[0100] Physical basis: When the liquid water content exceeds the water content threshold, the capillary attraction and adhesion between particles dominate the movement, regardless of... Both the size and the snow flow exhibit highly viscous plastic flow characteristics.

[0101] Criterion C: Dense dry snow / subcritical flow: and ;

[0102] Physical basis: Low-speed, dry snow flow has insufficient kinetic energy and mainly undergoes gravity deposition.

[0103] The time-varying parameter sequence of the control section is encapsulated with the flow regime identification code to obtain the control section parameter set. The output items of the control section parameter set are the velocity vector sequence, flow depth sequence, evolution density sequence and flow regime identification code.

[0104] S2. Map the control section parameter set to the snow-facing / snow-repelling surface of the tower, and introduce lattice transmission, dynamic blocking and group shading correction to form the time history of the total incident kinetic energy intercepted by the structure.

[0105] A geometric model of the digital twin of the transmission tower is established and divided into multiple height micro-segments along the tower height direction. A list of tower micro-segments is compiled and used to provide the height index and spatial location of the snow-facing and snow-repelling surfaces.

[0106] Based on the list of micro-element segments of the tower, mark the spatial identifiers of the snow-facing and snow-repelling surfaces and compile them into an action surface identifier table, defining the snow-receiving direction and projection direction of the snow-facing and snow-repelling surfaces.

[0107] The control section parameter set is projected onto the height micro-segment corresponding to the action surface identification table according to the time series and spatial interpolation is performed to obtain the action surface time-varying parameter mapping sequence. The action surface time-varying parameter mapping sequence includes the time-by-time distribution of the velocity vector sequence, flow depth sequence and evolution density sequence of the snow-facing action surface and the snow-back action surface.

[0108] Perform consistency checks on the snow-facing and snow-repelling directions of the time-varying parameter mapping sequence of the action surface and output the flow field mapping sequence packet of the action surface, locking the sign and direction conventions of the velocity components in the snow-facing and snow-repelling directions.

[0109] The total projected area of ​​the snow-facing truss components perpendicular to the flow direction is extracted from the list of micro-elements along the tower. Simultaneously, the macroscopic envelope area of ​​the height micro-elements is calculated to form a sequence of geometric features for the snow-facing surface. This sequence is used to define the initial solidity ratio of the snow-facing surface, specifically:

[0110] ;

[0111] in, Indicates height coordinates as The initial solidity ratio of the snow-facing surface is used to characterize the proportion of solid components in the lattice structure on the snow-facing surface, thus affecting the initial state of transmission and blockage. Represents the projected area of ​​a single component; It represents the contour envelope area (macroscopic outer envelope area) of the snow-facing surface of the corresponding height element segment in the windward direction, and is used as the denominator to form a dimensionless reality ratio.

[0112] Map the avalanche fluid velocity field in the flow field mapping sequence package to the incident velocity on the snow-facing surface and record the impact velocity on the snow-facing surface. The impact velocity on the snow-facing surface satisfies:

[0113] ;

[0114] in, Indicates height coordinates as , time is The impact velocity of the snow-facing surface on the snow-facing surface (the incident velocity of the snow-facing surface) is used for subsequent blockage evolution, group shading correction and incident power calculation; The flow field mapping sequence at the action surface is represented by the height coordinates. , time is The avalanche fluid velocity (the local velocity obtained by mapping) is used as the source of the impact velocity on the snow-facing surface.

[0115] Extract the projected area of ​​the snow-facing truss components from the tower micro-element list and record it as the snow-facing component area. Simultaneously extract the projected area of ​​the snow-receding truss components and record it as the snow-receding component area. For conventional lattice towers, the snow-facing component area and the snow-receding component area are usually approximately equal, specifically:

[0116] ;

[0117] in, This represents the area of ​​the snow-facing surface components in their initial state (the total or equivalent amount of the projected area of ​​the snow-facing surface truss components). This represents the area of ​​the snow-covered component in its initial state; symbol This indicates that for a conventional lattice tower type, the snow-facing side and the snow-repelling side are usually geometrically symmetrical, so the projected areas of the components on both sides are usually approximately equal, which simplifies the configuration and verification of the initial geometric quantities on the snow-facing / snow-repelling sides.

[0118] The blockage effect during avalanche impact mainly occurs on the snow-facing side; as snow particles adhere and bridge, the effective stress-bearing area on the snow-facing side increases dramatically, while the snow-repellent side mainly maintains the original shape of the structure; based on the water content and flow regime output by S1, the blockage evolution coefficient of the tower lattice is defined, and the degree of blockage is distributed in (0~1):

[0119] ;

[0120] in, Indicates time The blockage evolution coefficient characterizes the increase in blockage degree on the snow-facing surface over time and controls the adaptive amplification of the effective force-bearing area of ​​the snow-facing surface. Its values ​​are distributed in... ; Indicates time Representative value of the impact velocity of the snow-facing surface (which can be obtained from the height micro-element). (Summarized in segments), used to reflect the driving effect of flow velocity on the rate of blockage growth; It represents the average net clearance between components and is used to characterize the control effect of lattice pore size on the ease of blockage formation.

[0121] Based on this, the dynamic effective stress area of ​​the snow-facing surface is calculated as follows:

[0122] ;

[0123] in, Indicates height coordinates as , time is The dynamic effective force-bearing area on the snow-facing side is used to convert the blockage effect into a time-varying amplification of the effective windward area on the snow-facing side and participate in the incident power calculation. The reference value representing the area of ​​the snow-facing surface component at the height micro-element segment (which can be compared with...) (consistent), used as the initial force-bearing area before blockage; This represents the envelope area of ​​the snow-facing surface at the height micro-element segment, which is used as the upper limit of the area when the blockage is completely saturated. Represents the congestion evolution coefficient, used in... and To achieve an adaptive transition between them, when hour, ,when hour, .

[0124] After the snow flow passes through the snow-facing side, its velocity decreases, and the impact velocity on the snow-receiving side increases. Significantly smaller than The effective area of ​​the snow-covered surface remains the same as the area of ​​the solid component, i.e.:

[0125] ;

[0126] The effective impact velocity on the snow-backed surface is determined using a nonlinear obstruction attenuation formula that considers the degree of front-row blockage. Specifically:

[0127] ;

[0128] in, Indicates height coordinates as , time is The residual impact velocity on the snow-back side is used to characterize the velocity attenuation of the snow flow when it reaches the snow-back side after passing through the snow-facing grid and blockage area, and is also used in the calculation of the incident power on the snow-back side. This represents the group shading factor, used to characterize the intensity of velocity attenuation on the back side due to snow-facing grids and blockages. Its value ranges from 0.8 to 1.0, with a higher value indicating more severe blockage. The larger the flow rate, the higher the velocity. The smaller the value, the less impact the snow-covered surface will bear when the snow is completely blocked.

[0129] By integrating the asymmetric characteristics, area, and velocity parameters of the snow-facing and snow-repellent surfaces of the tower grid, the total destructive power density acting on the tower's infinitesimal segment per unit time is calculated, and the total impact energy is obtained by integrating over time. Specifically:

[0130] ;

[0131] in, This represents the total impact energy corresponding to the combined effect of avalanche fluid on the snow-facing and snow-repelling sides of the tower within the analysis time window; Indicates the total analysis time of the impact process or the upper limit of the selected time window; This indicates the range of tower heights included in the impact calculation or the upper limit of the effective impact height. It is a commonly used coefficient in the form of kinetic energy flux, used to convert velocity flux into a dimensionless scale consistent with kinetic energy. The drag coefficient represents the ability of a component's shape to impede fluid flow. For angle steel commonly used in transmission towers, its sharp edges and corners provide strong fluid gripping ability, and the drag coefficient is typically [value missing]. If it is a round steel pipe, the resistance coefficient is usually small (about 1.2). Indicates time avalanche fluid density; Indicates time The effective stress area on the snow-covered side.

[0132] After quantifying the total incident kinetic energy of the avalanche fluid acting on the effective windward surface of the tower structure, considering dynamic blockage and group shielding effects, this energy value will serve as the basic input for calculating the effective disaster-causing energy in subsequent steps. Based on the previously calculated effective snow-facing area (as blockage increases) and effective snow-repelling area (keeping the structure unchanged), as well as the corrected velocity distribution, an incident power integral equation is constructed, specifically:

[0133] ;

[0134] in, This represents the total incident kinetic energy (structural interception incident kinetic energy) formed by the combined action of avalanche fluid on the snow-facing and snow-repelling sides of the tower within the time interval. It is used as the basic energy term for subsequent medium dissipation deduction and effective disaster-causing energy synthesis. Indicates the incident power on the snow-facing side; This indicates the incident power on the snow-covered side.

[0135] It should be noted that the total kinetic energy of the avalanche jet has not yet deducted the internal energy consumed by the snow medium during the impact due to fragmentation, compaction and phase change. Therefore, it is greater than the effective energy that ultimately destroys the tower.

[0136] The incident power on the snow-facing side represents the total flux of avalanche fluid kinetic energy intercepted by the snow-facing side of the tower (including the blocking surface), and its expression is:

[0137] ;

[0138] in, Indicates time The avalanche fluid density (which can be a representative value of the evolution density or the density mapped from the cross section / acting surface).

[0139] The incident power on the snow-backed side characterizes the impact flux of the residual fluid after passing through the front row onto the snow-backed side components, and its expression is:

[0140] ;

[0141] The effective force-bearing area of ​​the snow-facing surface, the effective area of ​​the snow-receiving surface, the blocking coefficient, the impact velocity of the snow-facing surface, the impact velocity of the snow-receiving surface, and the total incident kinetic energy of the structure interception are encapsulated and archived with a unified timestamp, and the time history and segmented distribution of the total incident kinetic energy of the structure interception are output (including the effective force-bearing area of ​​the snow-facing surface, the effective area of ​​the snow-receiving surface, the blocking coefficient, and the correction velocity).

[0142] S3. The energy dissipation time history of the total incident kinetic energy of the structure is quantified by adopting the energy dissipation mechanism of snow medium compaction and crushing, and the non-disaster internal energy loss is deducted to obtain the net impact kinetic energy time history and the medium dissipation energy time history.

[0143] The impact velocity time history and effective stress area time history of the snow-facing surface are extracted from the total incident kinetic energy time history of the structure and encapsulated with a unified timestamp to form an impact contact characteristic sequence. This impact contact characteristic sequence is then correlated with the evolution density sequence, water content sequence, and flow regime identifier code from the control section parameter set using a unified timestamp to obtain an energy dissipation parameter sequence. Based on the water content in the energy dissipation parameter sequence, the compaction yield stress is established, and the bulk modulus and upper limit of compressive strain are configured to obtain the compaction contact stress-strain relationship, specifically:

[0144] ;

[0145] in, Indicates instantaneous compaction stress (Pa); Indicates volumetric compressive strain; The moisture content is indicated as Initial yield strength at time; Indicates the bulk hardening modulus; It represents the ultimate compaction strain, characterizing the snow medium when compressed to the point where the pores are completely closed (i.e., the density of pure ice). Theoretical limit strain at time ) This represents the natural logarithm function.

[0146] To further explain, the expression for volumetric compressive strain is:

[0147] ;

[0148] The expression for the ultimate compaction strain is:

[0149] ;

[0150] By integrating the compaction contact stress-strain relationship over the compressive strain range and superimposing the latent heat of the compressive melting phase transformation, the unit volume energy consumption, which is the sum of the compaction plastic energy consumption and the compressive melting phase transformation energy consumption, is obtained. Specifically:

[0151]

[0152] in This represents the energy density dissipated per unit volume; Indicates the final compressive strain; Represents a strain element; This indicates the latent heat of fusion of ice; This indicates the localized increase in pressure melt density caused by high pressure (for wet snow flow).

[0153] For ease of engineering application, the following preferred engineering operator can be adopted, specifically:

[0154]

[0155] in, Indicates time Energy density dissipated per unit volume; This represents the energy consumption coefficient for media crushing (value range: 0.4~0.8). Indicates the initial density; Indicates time The impact velocity of the snow-facing surface; This indicates the latent heat of fusion of ice.

[0156] By combining the energy dissipation density per unit volume with the time history of the effective force-bearing area of ​​the snow-facing surface and the time history of the impact velocity of the snow-facing surface, the instantaneous dissipation power of the avalanche flow impacting the tower lattice structure is obtained, specifically:

[0157]

[0158] in, Indicates time The instantaneous power dissipation; Indicates time The effective stress-bearing area of ​​the snow-facing surface; The coefficient represents the compaction core distribution coefficient (values ​​range from 0.7 to 0.9). Since the angle steel components of transmission towers are bluff structures, a high-density compaction core is formed only in the central area of ​​the snow-facing surface during avalanche impact, and complete compaction and energy dissipation occur in this area; while the snow flow in the edge area undergoes shear flow around it, resulting in a lower degree of compaction. This coefficient is introduced to correct this uneven energy dissipation across the cross-section.

[0159] The instantaneous dissipated power is accumulated according to a unified timestamp to obtain the medium dissipated energy time history; the medium dissipated energy time history is time-aligned with the total incident kinetic energy time history of the structure interception and subtraction is performed to obtain the net impact kinetic energy time history, and the output time axis of the net impact kinetic energy time history is kept consistent with that of the medium dissipated energy time history.

[0160] S4. Based on the net impact kinetic energy time history, quantify the additional disaster contribution of the stagnant accumulation in front of the tower and the climbing effect along the tower, and obtain the additional potential energy time history.

[0161] The formation period of the stagnant accumulation zone in front of the tower was identified by the time history of the impact velocity on the snow-facing surface corresponding to the net impact kinetic energy time history and the time history of the effective force-bearing area on the snow-facing surface. The accumulation range was marked by combining the projection range of the foundation in front of the tower in the action surface identification table, and the evolution record of the accumulation zone was obtained. Among them, the projection range of the foundation in front of the tower is a closed area that extends 1.0m to 2.0m outward from the outer contour projection of the foundation to cover the lateral diffusion and shear slip zone at the edge of the foundation and to serve as a geometric constraint for the continuous static pressure distribution. The accumulation range extends 5m to 15m outward from the front edge along the snow-facing direction based on the projection range of the foundation in front of the tower, and extends 3m to 10m outward on each side laterally to cover the length of the stagnant accumulation front edge and the lateral widening around the flow and to avoid the boundary truncation leading to the underestimation of the accumulation static pressure potential energy time history.

[0162] When avalanche fluid impacts a tower, a continuously evolving stagnant accumulation zone forms at the base of the tower on the snow-facing side, generating continuous passive earth pressure on the tower legs and creating shear failure potential energy. The accumulation height time history is calculated based on the accumulated intercepted volume flux in the accumulation zone evolution record and written into the accumulation zone evolution record. The accumulation height time history satisfies the following:

[0163] ;

[0164] in, Indicates time The height of the pile in front of the tower; This means taking the smaller of the two values ​​to limit the stacking height from exceeding the upper limit; express The volumetric flux of avalanche fluid that is constantly blocked by the snow-facing surface of the tower (after considering the blockage effect); This represents the projected area of ​​the tower base corresponding to the area of ​​accumulation effect. This indicates the maximum stacking height limited by the angle of repose.

[0165] To further explain, the time history of the interception volume flux on the snow-facing side is obtained by combining the time history of the effective force-bearing area of ​​the snow-facing surface and the time history of the impact velocity of the snow-facing surface, specifically:

[0166] ;

[0167] in, Indicates time The effective stress-bearing area of ​​the snow-facing surface; Indicates time The impact velocity of the snow-facing surface.

[0168] The evolution record of the accumulation zone is converted into a calculation input for the continuous static pressure distribution. Using the accumulation height time history, accumulation density time history, and accumulation width as constraints, the potential energy contribution of the work done by static pressure is calculated, generating the accumulation static pressure potential energy time history. The accumulation static pressure potential energy time history satisfies the following:

[0169] ;

[0170] in, Indicates time The accumulated static pressure potential energy; Indicates the passive side pressure coefficient; Indicates time The snow density in the accumulation zone is obtained by taking the value of the evolution density sequence of the control section parameter set in the corresponding time period of the accumulation zone in front of the tower. This indicates the equivalent width of the accumulation effect in the direction facing the snow.

[0171] To further explain, based on the evolution record of the accumulation zone, the static pressure coefficient is configured and written into the calculation input of the accumulation static pressure potential energy time history. The static pressure coefficient satisfies:

[0172] ;

[0173] in, Indicates the static pressure coefficient; Represents the tangent function; This indicates the internal friction angle of accumulated snow.

[0174] When avalanche fluid encounters a tower, some of its horizontal kinetic energy is converted into gravitational potential energy, causing the snow flow to rise along the tower and raising the point of application of the resultant force of the avalanche flow (increasing the lever arm). This generates a significant additional eccentric overturning moment on the tower foundation. Based on Bernoulli's energy equation, the climbing stage along the tower corresponding to the net impact kinetic energy time history is identified, and the climbing height time history is calculated based on the impact velocity time history of the snow-facing surface. The expression is as follows:

[0175] ;

[0176] in, Indicates time The height of the tower as it climbs; This represents the avalanche kinetic energy to potential energy conversion efficiency coefficient (considering viscous losses). For dry powder snow, For wet, sticky snow, due to its viscosity and dissipation, .

[0177] The added mass of snow mass ascended to a higher altitude is defined as... The overturning work it does relative to the tower foundation is:

[0178] ;

[0179] in, Indicates time The potential energy of climbing and overturning; Indicates time The additional mass gained from climbing; This indicates the height of the fluid's center of gravity before it climbs. Represents the sine function; This indicates the axial deflection angle caused by the bending deformation of the tower or the rotation of the foundation due to the horizontal impact force of an avalanche.

[0180] The time history of accumulated static pressure potential energy and the time history of climbing and overturning potential energy are aligned with a unified timestamp and then merged to obtain an additional potential energy time history. The additional potential energy time history satisfies the following:

[0181] ;

[0182] in, Indicates time Additional potential energy; This represents the time history component of the accumulated static pressure potential energy; This represents the time-history component of the potential energy for climbing and overturning.

[0183] S5. Summarize the time history of the total incident kinetic energy, the time history of the medium dissipation energy, and the time history of the additional potential energy of the structure, and complete the full time history synthesis. Through the finite element stability assessment of the tower and the multi-level early warning judgment, output the effective disaster energy quantification result package.

[0184] The receiver obtains the time history of the total incident kinetic energy, the time history of the dissipated energy of the medium, and the time history of the additional potential energy. It then extracts the timestamp set and the total analysis duration from the time history of the total incident kinetic energy, the time history of the dissipated energy of the medium, and the time history of the additional potential energy. These are then summarized to form a timestamp set list and the total analysis duration, which are used to unify the time window boundaries for time axis resampling.

[0185] The sampling step size of the unified time axis is determined based on the timestamp set list, and the unified time axis is generated within the time interval. The sampling step size is taken as the minimum value of the interval between adjacent timestamps of the time history of the total kinetic energy intercepted by the structure, the time history of the energy dissipated by the medium, and the time history of the additional potential energy, or the unified step size set by the project, so as to ensure that the unified time axis covers the full time history changes of the time history of the total kinetic energy intercepted by the structure, the time history of the energy dissipated by the medium, and the time history of the additional potential energy.

[0186] The time histories of the total incident kinetic energy, the dissipated energy of the medium, and the additional potential energy are resampled along a unified time axis to generate an aligned energy sequence. The resampling uses linear interpolation based on timestamps or zero-order hold to map the time histories of the total incident kinetic energy of the structure to an aligned sequence of the total incident kinetic energy of the structure, the time histories of the dissipated energy of the medium to an aligned sequence of the dissipated energy of the medium, and the time histories of the additional potential energy to an aligned sequence of the additional potential energy. Each timestamp of the aligned energy sequence simultaneously contains the aligned sequence of the total incident kinetic energy of the structure, the aligned sequence of the dissipated energy of the medium, and the aligned sequence of the additional potential energy.

[0187] The aligned energy sequences are aggregated according to the energy conservation relationship to form the effective disaster-causing energy time history. The energy synthesis value of the effective disaster-causing energy time history at the total analysis duration is taken as the full-time history synthesis result of the effective disaster-causing energy. The full-time history synthesis result of the effective disaster-causing energy satisfies:

[0188]

[0189] in, Indicates effective disaster-causing capacity.

[0190] The energy component contribution rate is statistically analyzed on the time history of the effective disaster-causing energy to obtain the composite result set of the effective disaster-causing energy. The energy component contribution rate statistics include the proportion of net impact kinetic energy and the proportion of additional potential energy. The proportion of net impact kinetic energy satisfies the following:

[0191] ;

[0192] ;

[0193] Establish a finite element model of the transmission tower, configure material parameters, boundary constraints and key component connection relationships, and generate a tower finite element model package; the material parameters should at least include the elastic parameters and yield parameters corresponding to angle steel, bolted connections or welded connections, the boundary constraints should at least include the displacement constraints and rotation constraints at the connection between the tower foot and the foundation, and the key component connection relationships should at least include the connection topology and connection stiffness expression of the main members, diagonal members and horizontal members at the node plate.

[0194] The effective disaster-causing energy synthesis result set is associated with the tower finite element model package, and the tower's load-bearing ultimate strain energy is calculated to obtain the structural ultimate energy benchmark. The structural ultimate energy benchmark includes the tower's load-bearing ultimate strain energy and elastic ultimate strain energy. The elastic ultimate strain energy is determined by the elastic segment before yielding of the load-displacement curve.

[0195] To further explain, the expression for calculating the ultimate strain energy that the tower can withstand is as follows:

[0196] ;

[0197] in, To ensure that the tower can withstand ultimate strain energy, The load-displacement curves of the finite element model of the transmission tower are shown. This is the ultimate displacement.

[0198] The effective disaster-causing energy time history is compared with the structural ultimate limit energy benchmark in a graded manner to generate multi-level early warning results. The graded comparison satisfies the following:

[0199] Safe status: , The elastic limit energy of the tower is present, and the structure exhibits no permanent deformation.

[0200] Damage status: The tower experienced localized angle steel yielding or plastic deformation, but did not collapse; reinforcement is required.

[0201] Damaged state: If the energy exceeds the structure's energy absorption limit, it is determined to be a collapse, wire breakage, or pull-out failure.

[0202] The multi-level early warning results and the effective disaster-causing energy synthesis result set are encapsulated and archived to output the effective disaster-causing energy quantification result package. The effective disaster-causing energy quantification result package includes the effective disaster-causing energy time history, the effective disaster-causing energy synthesis result set and the multi-level early warning results, and maintains the consistency of the effective disaster-causing energy time history with the time history of the total kinetic energy of the structural interception incident, the time history of the medium dissipation energy, and the time history of the additional potential energy.

[0203] This embodiment also provides a computer device applicable to the method for quantifying the impact damage energy of avalanches on transmission towers, comprising: 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 method for quantifying the impact damage energy of avalanches on transmission towers as proposed in the above embodiment.

[0204] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0205] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the method for quantifying the impact damage energy of avalanches on transmission towers as proposed in the above embodiments. The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0206] In summary, this invention integrates the free-field time-varying flow field parameters, flow regime identification codes, and the time-varying effective force-bearing area and residual velocity on the snow-facing / snow-repelling surfaces of the tower into an energy conservation framework, forming a closed-loop quantitative link of the total incident kinetic energy, medium dissipation energy, and additional potential energy. This significantly reduces the energy deviation caused by fixed windward area, unilateral impact, and neglecting transmission shielding. Based on the energy dissipation mechanism of snow compaction and breakage, the non-disastrous internal energy loss caused by compaction plastic deformation, particle breakage, and wet-sticky snow melting phase transition is explicitly deducted, making the contribution boundaries of net impact kinetic energy and additional potential energy clear, and improving the physical consistency and interpretability of the effective disaster-causing energy time history. After the effective disaster-causing energy quantification results are connected with the finite element stability assessment of transmission towers, a structural limit energy benchmark can be obtained and multi-level early warning judgment can be realized, thereby improving the reliability of risk classification, reducing false alarms and missed alarms, and providing a unified quantitative basis for protection design and operation and maintenance decisions under different flow regimes.

[0207] Example 2, referring to Table 1, is the second embodiment of the present invention. To further verify the technical solution of the present invention, experimental simulation data of the quantification method of the impact damage energy of avalanches on transmission towers are given.

[0208] A common reference transmission tower (lattice-type angle steel tower) was selected as the object. After extracting the slope aspect, slope, and confluence path using a high-precision on-site DEM, an avalanche simulation calculation grid was constructed. The DEM was resampled to a 5m grid resolution (2–10m can be selected, depending on the terrain analysis requirements of the confluence path / slope abrupt change and the numerical stability of SWE). The boundary range was set to extend outward according to the main confluence path (200–500m upstream, 300–800m downstream of the tower downstream, and 200–500m on each side laterally) to ensure the full development of the free field and suppress boundary reflection. Initial snow source conditions were configured for three types of flow: dry powder snow / supercritical flow (low water content, high Fr), wet sticky snow / viscous flow (high water content), and dense dry snow / subcritical flow (low velocity, Fr≤1). The time histories of the free field time-varying velocity field, flow depth field, and evolution density field were solved.

[0209] A virtual control section is set up upstream of the snow-facing side (typically within 5–20m upstream of the center axis of the snow-facing side of the tower). Velocity, flow depth, and evolution density are extracted, and the Froude number is calculated. These parameters are combined with water content to form a two-parameter discrimination sequence, and a flow state identification code is output. Subsequently, the control section parameter set is mapped to the snow-facing / snow-repellent action surface of the tower: micro-segments are divided along the tower height to construct an action surface identification table; "lattice transmission-dynamic blockage" is introduced on the snow-facing side to adaptively amplify the effective force-bearing area over time, and "group shielding attenuation" is applied to the snow-repellent side to obtain the residual velocity, thereby forming the time history of the total kinetic energy intercepted by the structure. Furthermore, the energy dissipation time history of the medium is calculated according to the energy dissipation mechanism of snow medium compaction and crushing, and non-hazardous internal energy is deducted. Then, the additional potential energy caused by the stagnation and accumulation in front of the tower and the climbing along the tower is quantified, and finally, the effective hazardous energy is synthesized and connected with the tower finite element stability assessment to output an early warning classification.

[0210] Compared to the "conventional method," which employs industry-standard simplifications: the snow-facing surface uses a fixed windward / stress-bearing area, ignoring differences in dynamic blockage and group shielding; the energy chain does not explicitly deduct medium dissipation energy, nor does it include accumulated static pressure potential energy and overturning potential energy, thus approximating the disaster-causing energy with incident energy. The equivalent disaster-causing energy obtained from finite element inversion is used as a reference value to compare the energy error and early warning consistency of the two methods.

[0211] The details are shown in Table 1 below:

[0212] Table 1. Comparative experimental data on the effective disaster-causing energy of transmission towers under avalanche flow conditions.

[0213] parameter Dry powder snow / supercritical flow - conventional method Dry Powder Snow / Supercritical Flow - This Invention Wet sticky snow / viscous flow - conventional method Wet sticky snow / viscous flow - This invention Dense dry snow / subcritical flow - conventional method Dense dry snow / subcritical flow - This invention Moisture content W (%) 1.5 1.5 6 6 2 2 Peak Froude number 1.8 1.8 0.9 0.9 0.6 0.6 Peak impact velocity of snow surface 32 32 18 18 6 6 Peak effective stress area of ​​snow-facing surface 8 11 8 22 8 10 Total incident kinetic energy (MJ) intercepted by the structure 13 18 10 32 1.2 1.6 Dielectric dissipation energy (MJ) 0 6 0 18 0 0.4 Additional potential energy (MJ) 0 7 0 12 0 30 Effective disaster-causing energy (MJ) 13 19 10 26 1.2 31.2 Effective disaster-causing energy inversion value (MJ) 20 20 27 27 30 30 Relative error of effective disaster-causing energy (%) -35 -5 -62.96296296 -3.703703704 -96 3.9999999999999973 Warning Level safe status Damage status safe status Damage status safe status Destroyed state

[0214] From the perspective of incident energy, the differences among the three flow regimes are revealed in the "time-varying nature of effective force-bearing area": ​​under the driving force of blockage evolution, the peak effective force-bearing area of ​​wet sticky snow on the snow-facing surface increases from 8m² to 22m², and the incident energy increases from 10MJ to 32MJ, directly reflecting the working condition of "blockage forming a wall of force"; dry powder snow only undergoes partial blockage (8→11m²), and the increase in incident energy is moderate (13→18MJ); dense dry snow has low velocity and low kinetic energy background (about 1MJ), and its contribution to disaster is naturally limited.

[0215] From the perspective of energy consumption and additional energy, this invention explicitly separates "non-disastrous internal energy loss" from "additional disastrous potential energy," forming an explainable energy closed loop: the medium dissipation energy of wet sticky snow reaches 18MJ (pressure melting phase change energy absorption is dominant), while the accumulation static pressure potential energy contributes 12MJ; the medium dissipation energy of dry powder snow is moderate (6MJ, mainly due to crystal breakage / compaction), but the climbing and overturning potential energy contribution is significant (7MJ), corresponding to the "impact + overturning" failure path; although the dissipation energy and incident energy of dense dry snow are both small, the accumulation static pressure leads to an additional potential energy as high as 30MJ, which is consistent with the mechanism characteristics of "mass accumulation - static pressure burial failure".

[0216] From the perspective of consistency between disaster-causing modes and engineering judgments, conventional methods systematically underestimate disaster-causing energy due to the incomplete energy chain: the relative errors of E_eff for the three flow states reach -35%, -63%, and -96%, respectively, and in the early warning, the working conditions that should have entered the "damage / destruction" stage are misjudged as "safe". This invention, through closed-loop quantification of "dynamic force-bearing area + group shielding velocity correction + medium dissipation deduction + accumulation / climbing additional potential energy", brings the error to -5%, -3.7%, and +4.0%, respectively. At the same time, it classifies wet sticky snow as "damage state with significant risk of overall knockdown" and dense dry snow as "destruction state", which is more in line with the needs of disaster-causing mechanism classification and stability assessment under different flow states.

[0217] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for quantifying the impact damage energy of an avalanche on a transmission tower, characterized in that: include, Obtain the DEM, slope distribution and initial snow source conditions of the slope where the target tower is located, and complete the avalanche dynamic simulation. Set up a virtual control section upstream on the snow-facing side to extract the free field time-varying flow field parameters and determine the flow regime type to obtain the control section parameter set. The control section parameter set is mapped to the snow-facing / snow-repelling surface of the tower, and lattice transmission, dynamic blocking and group shading corrections are introduced to form the time history of the total incident kinetic energy intercepted by the structure. The energy dissipation mechanism of snow medium compaction and crushing was used to quantify the total incident kinetic energy time history of the structure interception and deduct the non-hazardous internal energy loss to obtain the net impact kinetic energy time history and the medium dissipation energy time history. The additional potential energy time history is obtained by quantifying the additional disaster-causing contribution of pre-tower stagnation and accumulation and the climbing effect along the tower based on the net impact kinetic energy time history. The system summarizes the time histories of the total incident kinetic energy, the energy dissipated by the medium, and the additional potential energy, and completes the full time histories synthesis. Through finite element stability assessment of the tower and multi-level early warning determination, it outputs an effective disaster-causing energy quantification result package.

2. The method for quantifying the impact damage energy of an avalanche on a transmission tower as described in claim 1, characterized in that: The process of obtaining the DEM, slope distribution, and initial snow source conditions of the slope where the target tower is located, and completing the avalanche dynamic simulation, specifically involves: Read the DEM of the slope where the target tower is located and extract the slope aspect, slope and runoff path features, and summarize them to obtain the terrain raster parameter set; The terrain raster parameter set is converted into an avalanche simulation calculation mesh, and the mesh resolution and boundary range are configured to generate the simulation scene mesh. The initial conditions of the snow source are collected and its spatial distribution is mapped to the simulation scene mesh to obtain the initial field of the snow source; the initial conditions of the snow source include the initial density and water content; The initial field of the snow source is solved by time progression, and the time history evolution of the velocity field, flow depth field and density field is recorded to generate a set of simulation results for the avalanche free field.

3. The method for quantifying the impact damage energy of avalanches on transmission towers as described in claim 1, characterized in that: The obtained control section parameter set is specifically as follows: Within the avalanche free field simulation result set, a cross-sectional position intersecting with the tower axis is selected upstream along the snow-facing side to generate a virtual control cross-section. Velocity, flow depth and evolution density are sampled at time intervals along the virtual control section and time-stamped to obtain the time-varying parameter sequence of the control section; The dynamic Froude number is calculated based on the time-varying parameter sequence of the control section, and the water content in the initial conditions of the snow source is collected to form a two-parameter discrimination sequence. Perform flow state type determination on the two-parameter discrimination sequence, generate flow state identification code, encapsulate the time-varying parameter sequence of the control section with the flow state identification code, and obtain the control section parameter set.

4. The method for quantifying the impact damage energy of an avalanche on a transmission tower as described in claim 1, characterized in that: The mapping of the control section parameter set to the snow-facing / snow-repelling surface of the tower specifically involves... Establish a geometric model of the digital twin of the transmission tower, divide it into micro-segments according to the height direction, and generate a list of tower micro-segments; Based on the list of tower micro-segments, spatial identifiers for the snow-facing and snow-repelling surfaces are constructed, forming a surface identifier table; The control section parameter set is projected onto the height micro-element corresponding to the action surface identification table according to the time series, and spatial interpolation is performed to obtain the time-varying parameter mapping sequence of the action surface; The consistency of the time-varying parameter mapping sequence of the action surface with the snow-facing and snow-backing directions is checked, and the flow field mapping sequence package of the action surface is generated.

5. The method for quantifying the impact damage energy of an avalanche on a transmission tower as described in claim 1, characterized in that: The time history of the intercepted total incident kinetic energy by the structure is specifically as follows: The projected area of ​​the truss components on the snow-facing surface is extracted from the flow field mapping sequence of the action surface, and the contour envelope area is calculated to obtain the geometric feature sequence of the snow-facing surface. The geometric feature sequence of the snow-facing surface is associated with the flow regime identification code and the blockage coefficient is updated so that the effective force-bearing area of ​​the snow-facing surface changes adaptively with time, forming the effective force-bearing area time history. A group shading attenuation correction was applied to the residual velocity on the snow-covered side to form a snow-facing / snow-covered velocity field control sequence. Based on the snow-facing / snow-backing velocity field comparison sequence, the incident power time histories of the snow-facing and snow-backing surfaces are calculated and time histories are integrated to obtain the total incident kinetic energy time histories of the structure.

6. The method for quantifying the impact damage energy of an avalanche on a transmission tower as described in claim 1, characterized in that: The energy dissipation mechanism of snow compaction and crushing refers to the energy dissipation mechanism caused by compaction plastic deformation, particle crushing, and wet viscous snow melting phase transformation during the impact contact process of avalanche media.

7. The method for quantifying the impact damage energy of an avalanche on a transmission tower as described in claim 1, characterized in that: The net impact kinetic energy time history and the medium dissipation energy time history are obtained specifically as follows: The impact velocity time history and effective force-bearing area time history of the total incident kinetic energy of the structural interception are extracted from the time history of the snow-facing surface to form an impact contact characteristic sequence. By associating the impact contact characteristic sequence with the evolution density, water content, and flow regime identification code in the control section parameter set, an energy dissipation parameter sequence is obtained. Based on the energy consumption parameter sequence, the energy consumption of compaction plasticity, crushing and compressive melting phase transformation are calculated separately, and summarized into the medium dissipation energy time history; The time history of the medium dissipation energy is time-aligned with the time history of the total incident kinetic energy of the structure interception, and then subtraction is performed to obtain the net impact kinetic energy time history.

8. The method for quantifying the impact damage energy of an avalanche on a transmission tower as described in claim 1, characterized in that: The time history for obtaining the additional potential energy is specifically as follows: The formation period of the stagnant accumulation zone in front of the tower was extracted from the net impact kinetic energy time history, and the accumulation range was marked to obtain the accumulation zone evolution record; The evolution record of the accumulation zone is converted into a continuous static pressure distribution, and the potential energy contribution of the work done by the static pressure is calculated to generate the accumulation static pressure potential energy time history. Identify the climbing stage along the tower corresponding to the net impact kinetic energy time history and extract the changes in climbing height and impact location to obtain the climbing evolution record; The potential energy conversion and the contribution of eccentric overturning potential energy caused by lever arm lifting are calculated by climbing evolution records, and the climbing overturning potential energy time history is generated. By merging the time history of accumulated static pressure potential energy with the time history of climbing and overturning potential energy, and keeping the time alignment, an additional potential energy time history is obtained.

9. The method for quantifying the impact damage energy of an avalanche on a transmission tower as described in claim 1, characterized in that: The completion of the full-time synthesis specifically refers to... The time histories of total incident kinetic energy, medium dissipated energy, and additional potential energy are resampled along a unified time axis to generate an aligned energy sequence. The aligned energy sequence is aggregated according to the energy conservation relationship to form an effective disaster-causing energy time history; The contribution rate of energy components is statistically analyzed on the time history of effective disaster-causing energy to obtain a set of effective disaster-causing energy synthesis results.

10. The method for quantifying the impact damage energy of an avalanche on a transmission tower as described in claim 1, characterized in that: The output of the effective disaster-causing energy quantification result package is specifically as follows: Establish a finite element model of the transmission tower, configure material parameters, boundary constraints and key component connection relationships, and generate a finite element model package for the tower; The effective disaster-causing energy synthesis result set is associated with the tower finite element model package, and the ultimate strain energy that the tower can bear is calculated to obtain the structural ultimate energy benchmark. The effective disaster-causing energy time history is compared with the structural limit energy benchmark in a graded manner to generate multi-level early warning results; The multi-level early warning results are combined with the effective disaster-causing energy synthesis result set, which is then packaged and archived to output the effective disaster-causing energy quantification result package.

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