Abstract：By using the finite element analysis software of ANSYS and by taking one tower in Minping transformation line as the background of the research, a spatial finite element model is established. By means of modal analysis, the first ten natural frequency and vibration modes are obtained and modal characteristics are summarized. The response difference among three dimensional seismic waves is analyzed by a time-history analysis method. The analysis results show that the support pressure and moment of a tower under an earthquake action have a larger growth than that of the tower under a weight action. What is more, the difference of different types of seismic wave amplitudes of acceleration responses is very large. The conclusion shows that it is a key factor for the design to make clear the type of site soil on which the structure is located. In a word, the influence of the seismic action on the foundation cannot be ignored. The displacement of a tower head node conforms to the requirements of the aseismic code. The conclusion provides a theoretical basis for the further control research.

Keyword：modal analysis;seismic action;displacement;acceleration;time history analysis;