ANALYSIS OF RESPONSE OF ANCIENT TIMBER BUILDINGS ON THE HIGH PEDESTAL UNDER RANDOM EARTHQUAKE EXCITATIONS

In order to study the response characteristics of ancient timber buildings on the high pedestal under random earthquake excitations，the finite element models of Xian drum-tower which included the high pedestal，the upper timber structure and the overall structure were established． The reasonable earthquake vibration model was selected， and the analysis on response of drum-tower under random earthquake excitations was carried out by the absolute displacement solution based on pseudo excitation method and the harmonic response analysis of ANSYS program． The displacement and acceleration response power spectral density of the nodes of column were obtained． The results show that the peak values of the displacement and acceleration response power spectral density of structure occur at its basic frequency value． The high pedestal changes the magnitude and regularity of distribution of the displacement and acceleration response power spectral density of the structure，and also makes the peak values of the displacement and acceleration response power spectral density increase． Therefore，the high pedestal is unfavorable for the seismic performance of the overall structure and its unfavorable influence must be taken into account in structural analysis．