Experimental Research On The Collapse Of Large Span Transmission Tower-line System Under Strong Earthquake

The promulgation of?The 13th Five-Year Plan for Electric Power Development?(2016-2020)marked that the electric power industry has entered a new stage of development.As the areas of the power grid development,uhv and hv transmission technology will be applied to the West-East electricity transmission project.As the main carrier of uhv and hv transmission technology,uhv and hv transmission tower-line systems solved the problems of long distance transmission and complicated geological condition.Earthquakes occur more frequently in recent years,with the transmission network suffered destruction.Especially Wenchuan earthquake destroyed seriously the power grid,making the huge loss of disaster relief services and national economy.Research of dynamic response of large span transmission tower-line system under strong earthquake has the significant importance for the electric power development.However,there are few studies of experimental research and collapse theory of transmission tower-line system.Based on shaking table test and explicit analysis method,series of scale model shaking table test and the collapse simulation are studied in this paper.The three main aspects of studies done are listed as follows:(1)Based on the engineering practice,with linear elastic scale theory and the secondary scale design method,scale model design of large span transmission tower-line system is completed.The research of model material selection?model machining and boundary conditions simulation is carried out.The sensors were installed on the scale model,which is fixed on the shaking table.(2)The dynamic characteristic of tangent tower scale model is determined by white noise test.With the shaking table experiments under seismic wave,the studies of responses between tower-line system and tower,multi-dimensional seismic responses of tower-line system and responses of tower-line system under strong earthquake are carried out,studying weak region and position of initial fracture element of tower-line system.By the shaking table experiments under near-fault seismic waves,the study about seismic responses of tower-line system under the influence of seismic incident angle is carried out,studying critical incident angle of the tower-line system.(3)Based on the the user material subroutine which is considered the effect of material damage and member buckling,the collapse simulation of tower-line system under the multi-dimensional El Centro wave is comlpleted.By the comparison between finite element simulation results and shaking table test results,the feasibility of the user material subroutine and the accuracy of experiment results are studied.