동시베리아 지역의 지진 증폭 특성

초록

The thickness of permafrost in Eastern Siberia is from 200 to 500 meters. The seasonally frozen layer can vary from0 to 4m depending on ground temperature and its location. The shear wave velocity varies from 80m/s in summer to1500m/s in winter depending on soil type. When melted, large impedence will occur due to the difference betweenthe shear wave velocity of seasonally frozen soil and that of permafrost layer. Large displacement may occur at theboundary of the melted and the frozen layer, and this phenomenon should be considered in a seismic design. In thisresearch, one-dimensional equivalent linear analyses were performed to investigate the effects of the seasonally frozenlayer on ground amplification characteristics. Soil profiles of Yakutsk and Chara in Eastern Siberia were selected fromgeotechnical reports. 20 recorded ground motions were used to evaluate the effect of input motions. As the thicknessof seasonally frozen layer and the difference in the shear wave velocity increases, the amplification is shown to increase. Peat, very soft organic soil widely distributed throughout Eastern Siberia, is shown to cause significant ground motionamplification. It is therefore recommended to account for its influence on propagated motion.

키워드