| The safe operation of power grid is vulnerable to the influence of internal factorsand external factors, and transmission towers as the important part of transmission linesare affected by wind load, earthquake, hail, landslide and other natural disasters.High-voltage transmission tower built in ridge, steep edge of the river and other areas,due to its high flexible, is especially inevitable to landslides. Therefore, vulnerabilitystudy for transmission tower to landslides has important implications for grid securitymanagement. By studying safety risk assessment theory and landslide historicalstatistics, the paper conducts vulnerability analysis for towers to landslides, andvulnerability assessment was carried out for practical case. The main contents are asfollows:①Based on landslide probability and landslide spatial scope, landslide hazardwas analyzed.,and the resistance against natural disasters for transmission towers wasanalyzed on the basis of transmission tower’s spatial characteristics and its ownstructure, then the vulnerability assessment system for transmission towers sufferingfrom landslide was constructed. Based on landslide hazard and resistance againstnatural disasters for transmission towers, vulnerability assessment model fortransmission towers to landslide was set up.②Based on experience estimation method, landslide spatial scope is predictedand sliding velocity and sliding distance can be obtained. Landslide probability isdetermined by inner geological conditions, rainfall factors, and geological conditionsinclude lithology rock-soil structure hydrological condition and other factors,establishing the quantitative model for risk rating. Intraday rainfall and accumulativerainfall are included in rainfall, based on historical statistical data, using the interactionrelation matrix to analysis rainfall risk. Based on the comprehensive index method tocalculate the probability of landslides.③Select the relative locations transmission tower line and sliding direction andtransmission tower’s position relative to the slope as the spatial characteristics index,structural materials, tower main material, infrastructure protection facilities,infrastructure deep width ratio, tightness of timber, tower corrosion as its ownstructure’s index, then analysis the level of vulnerability.④Vulnerability assessment model was applied to500KV power transmission tower in Hubei western fold mountain. Sliding velocity obtained by calculated was44.5m/s, which is ultra high speed. Based on improved AHP method, the weights ofgeological condition indexes are calculated, and according to the research, theassignment of index was got. The calculation results showed that the geologicalcondition belonged to the high risk level. When intraday rainfall100mm andaccumulative rainfall150mm, the possibility of landslide was large. Based on the fuzzyhierarchy comprehensive evaluation method, the landslide hazard was high risk, theresistance against natural disasters for transmission towers was high vulnerability,vulnerability of transmission towers to landslide was IV high vulnerability. According tothe damage level table, the transmission tower will tilt. The vulnerability assessmentmodel has a certain reference significance. |
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