STUDY ON RESPONSE SPECTRUM CHARACTERISTICS OF EARTHQUAKE ACCELERATION FOR ROADBED ON PERMAFROST SITE
多年冻土场地路基地震加速度反应谱特性研究

At present,the aseismic problem of roadbed and other relevant earth structure on permafrost site has become a key problem that is not studied sufficiently in the past and needs to be solved urgently. Based on several typical cases of roadbeds of Qinghai-Tibet Railway Project,the response spectrum characteristics of earthquake acceleration for roadbed on permafrost site are studied by using two-dimensional dynamic FEM. The high-frequency El Centro wave and low-frequency Tianjin wave are input as an excitation. The result indicates that whether there is frozen layer,earthquake acceleration response spectrum is mostly the type of high frequency impulse,and the soil failure is bump type. In the mid and low frequency stage,the values of earthquake acceleration response spectrum for roadbed with frozen soil are larger than that without frozen soil when input is El Centro wave. But for Tianjin wave,there is no significant difference. Compared to different topography conditions,the frequence of input earthquake wave has great influence on earthquake acceleration response spectrum of roadbed. Especially,the existence of thawed basin ground enhances the effect of earthquake acceleration response for roadbed.