Uncertainty Response And Collapse Analysis Of Transmission Tower-Line System Under Earthquake

Transmission tower-line system is the carrier of electric power resource and an important lifeline project in China.It is an important guarantee for the sustainable development of the country’s economy as well as the normal progress of people’s work and life.As an important part of electric network,transmission towers are easily damaged or even collapsed during earthquakes.The failure and destruction of transmission towers under earthquakes will bring huge economic losses to society and even threaten people’s lives,health and safety,since our country is one of the countries with the most serious seismic hazards.At present,a series of researches have been achieved in the dynamic responses and failure analysis of many structure types under earthquakes.However,due to the limitation of understanding of the structure and the randomness in the research process,it is inevitable that the structural analysis will be affected.Encountering many uncertain factors,quantitative analysis of the impacts of these uncertain factors have become a hot issue in current research.In this paper,firstly the uncertainty response and collapse analysis of the transmission tower-line system under earthquakes are carried out,then the influence of multiple uncertain factors alone or in combination on the dynamic response and collapse of the transmission tower under the earthquake is studied,besides,the tower-line coupling effect and earthquake angle of incidence are obtained.Calculation model and analysis method for uncertainty analysis of transmission tower-line system under earthquake are established.Main research contents are generalized as follows:(1)Relying on the actual engineering of the transmission tower-line systems,the geometric size and material uncertainty parameters of the transmission tower structure were selected,considering the impact of the uncertainty of ground motion,finite element models of the transmission tower were established.Based on the sensitivity analysis method,the parameter sensitivity analysis considering uncertainties of the transmission tower under the earthquake is carried out,and the independent effect of a single uncertainty factor on the seismic response of the transmission tower is studied.(2)Based on the uncertainties related to the geometrical dimensions,materials and ground motions of the transmission tower,use Latin Hypercube Sampling(Latin Hypercube Sampling,LHS)and incremental dynamic analysis(Incremental Dynamic Analysis,IDA)combined method to carry out the uncertain response and collapse analysis of the exemplar transmission tower.Laws of the influence of different types of uncertain factors on uncertainty analysis of the exemplar transmission tower are also summarized.(3)Based on the sensitivity analysis and the LHS-IDA method,the uncertainty finite element model with three towers and four lines is established,considering the coupling effect of towers and lines as well as the influence of seismic incident angle.Nonlinear time history analysis is performed on uncertainty models to summarize the uncertainty response and collapse law of the exemplar transmission tower-line system.(4)From the two aspects,which are independence and linkage effects of uncertainty factors and different types of finite element model of transmission tower and transmission tower-line system,the comparison of the uncertainty analysis process and laws of different working conditions is obtained.The calculation model and analysis method of transmission tower under earthquake are established to provide reference for balanced calculation accuracy and speed of uncertainty analysis of transmission tower-line system.