The influence of earth temperature on dynamic characteristics of frozen soil and the parameters of ground motion at the sites of permafrost in the Qinghai-Tibet Plateau

摘要

Based on the field investigation on the west of Kunlun mountain pass 8.1 earthquake in 2001 and site exploration along Qinghai-Tibet Railway in China, the influence of temperature on dynamic constitutive relationship, dynamic elastic modulus and dynamic strength of frozen soil were studied quantitatively by means of dynamic triaxial test. Moreover, the characteristics of ground motion on permafrost site under different earth temperatures were analyzed for the four profiles of permafrost along the Qinghai-Tibet railway using the time histories of ground motion acceleration with 3 exceedance probabilities for Kunlun mountain area. The results show that earth temperature has predominant influence on seismic displacement, velocity, acceleration and response spectrum on permafrost sites. A scientific basis was presented for earthquake disaster prevention of structures, railways, highways and underground engineering in permafrost areas.