| Transmission towers are important kinds of high-rise structure which have beenbuilt in a large number. As a vital life line system, the destruction of transmission towerswill lead to the damage of the power system, which will also cause fire disaster andhuge propertyloss.Generally speaking, the span of transmission tower-line system is big, which isusually few hundred or even more than one thousand meters. As a result, there areabsolute differences between earthquake motions at different points.This has beenproved by many ground motion records, therefore multi-support excitations should beconsidered.In this paper, the Finite element model of the transmission tower, which is based onthe 5A-ZM2 500kV transmission line system, is built in ANSYS. Man-made seismicexcitations which consider traveling-wave effect, coherent effect and site effect are usedas loads. Large Mass Method is used to carry out multi-support excitations. Based onthe function of msc.dytran in ANSYS, the results of dynamic behavior and seismicresponse, which include response time history curve of acceleration and displacement attower top, response time history curve of internal force of main member and diagonalmember and peak value of acceleration and displacement at height divisions, areshowed, and have been compared with the results under simultaneous excitations.The results show that while considering traveling-wave effect, multi-supportexcitations will obviously amplify the seismic response of the model; while consideringcoherent effect and site effect, multi-support excitations will slightly amplify ordecrease seismic response of the model; while considering traveling-wave effect,coherent effect and site effect, multi-support excitations will mainly amplify the seismicresponse of the model.
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