The Researches On Earthquake Resistant Property Of Ancient Chinese Timber Structure

Chinese timber structures of Ming and Qing dynasty were much different fromstructures of Tang and Song dynasty in appearance and mechanical property. In Mingand Qing dynasty, the lateral stiffness of Dougong layer got bigger, the componentswere simplified, and the integrality of structure increased. The embrasure watchtower ofYongning Gate of Xi'an City Wall was typical multistory structure of Ming dynasty,which was ruined in1926. To recover the integrality of Xi'an City Wall, the embrasurewatchtower of Yongning Gate is going to rebuild. According to the requirement torebuild ancient architecture, the earthquake resistant property of this building should beanalyzed.In this paper, a partial structure model with the scale ratio of1:6of the embrasurewatchtower of Yongning Gate of Xi'an City Wall was made according to theKung–ch'eng tso-fa tse-li; the shaking table test was carried out, the test phenomenonwere observed. When the test was finished, the structure model components wereseparated, the damage quantification of structure element were observed, thedisplacement response, the acceleration response, the shear force, the joint moment andthe energy input and dissipation were analyzed. The test results show that, with theincreasing of the input simulated earthquake excitation, the stiffness of structure jointdecrease and get uniform, the phenomenon and the mode of vibration of twistdisappeared gradually, the natural frequency of the model get smaller, the damping ratioget increase, this result indicate that the structure model produced cumulative damage.The column feet and the Dougong layer possess performance of vibration isolation. Thesecond story is the weakest layer. The maximal value of the angle of displacement was 1/9, but the model didn't collapse, this result indicates that timber structure possessgood deformation properties, the column frame has good performance of vibrationsuppression. The distribution of shear force is very irregular. Plump shearforce—displacement hysteretic loop accounts for its good ability of energy dissipation.The hysteretic energy accounted for64.93%~73.88%of energy dissipation. The columnframes have stronger energy dissipation capacity than the Dougong layer, whichaccounted for91.8%~95.4%of total hysteretic energy dissipation.The results provide a basis for rebuilding the embrasure watchtower of YongningGate of Xi'an City Wall.