| With the rapid development of economy in our country, the demand for energy is growing quickly. In order to meet the needs of economic growth on electricity, our country implemented the development strategy of west to east electricity transmission and northto-south power transmission. As a result, the high-tension power transmission line and ultrahigh-tension power transmission line has been the main way of power transmission.China is in the earthquake-prone areas, so it has important practical significance to analyze the seismic performance of the transmission tower-line system. In the paper, the transmission tower of SZ301 is chosen as the research object and the peak value of earthquake wave is set at 8 degree basic fortification intensity. The acceleration and displacement of tower, peak value of acceleration and displacement of tower, internal force of member and support reaction are discused to study the seismic response of transmission tower-line system. It mainly include the following aspects:(1) Established models and then free vibration characteristics are carried out.(2) The dynamic influence of single-tower are studied and the results show that when the seismic wave is input along Z-direction, the seismic response is larger than that of X-direction; the displacement of tower body along excitation direction increase with tower height increase under three different seismic waves. The effect of dimension of seismic waves on seismic performance is researched and the results show that dimension of seismic waves has little effect on horizontal vibration of tower; that the internal force of main member is bigger than that of diagonal member has nothing to do with the dimension of seismic waves; the internal force of main member of tower for two or three-dimensional seismic waves input is bigger than that of one-dimensional and two or three-dimensional seismic waves input would amplify the seismic response of the model.(3) The dynamic influence of simplified model for transmission tower-line system is studied and the results show that the effect of lumped mass on displacement of tower is little under seismic action; the existence of the lumped mass lower the peak of acceleration and internal force of main member, as a result it reduces the secismic response of transmission tower.(4) The seismic response of transmission tower-line system with uniform seismic excitations input and multiple-support seismic excitations input method are analyzed. The time domain analysis method is used to explore the effect of conductor and groune wire on tower-line system and the result showe that the seismic response of conductor and groune wire on tower are closely correlated with spectral characteristic of seismic waves and motion characteristic of transmission line. What is more, large mass method is introduced to discuss the effect of wave travel effect on the tower-line system. While considering traveling-wave effect, the changing laws of time history curve of multiple-support excitations for EL-Centro wave input along Z-ditection are almost same with that of uniform excitations, but there existes phase difference;while considering traveling-wave effect, multi-support excitations will obviously amplify the seismic response of the model. |
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