Intensity measures for seismic liquefaction hazard evaluation of sloping site

CHEN Zhi-xiong(陈志雄)^{1, 2}, CHENG Yin(程印)³, XIAO Yang(肖杨)^{1, 2}, LU Liang(卢谅)^{1, 2}, YANG Yang(阳洋)^{1, 2}

(1. Key Laboratory of New Technology for Construction of Cities in Mountain Area of Ministry of Education (Chongqing University), Chongqing 400045, China;
2. School of Civil Engineering, Chongqing University, Chongqing 400045, China;
3. Kandilli Observatory and Earthquake Research Institute, Bogazici University, Istanbul 34684, Turkey)

Abstract:This work investigates the correlation between a large number of widely used ground motion intensity measures (IMs) and the corresponding liquefaction potential of a soil deposit during earthquake loading. In order to accomplish this purpose the seismic responses of 32 sloping liquefiable site models consisting of layered cohesionless soil were subjected to 139 earthquake ground motions. Two sets of ground motions, consisting of 80 ordinary records and 59 pulse-like near-fault records are used in the dynamic analyses. The liquefaction potential of the site is expressed in terms of the the mean pore pressure ratio, the maximum ground settlement, the maximum ground horizontal displacement and the maximum ground horizontal acceleration. For each individual accelerogram, the values of the aforementioned liquefaction potential measures are determined. Then, the correlation between the liquefaction potential measures and the IMs is evaluated. The results reveal that the velocity spectrum intensity (VSI) shows the strongest correlation with the liquefaction potential of sloping site. VSI is also proven to be a sufficient intensity measure with respect to earthquake magnitude and source-to-site distance, and has a good predictability, thus making it a prime candidate for the seismic liquefaction hazard evaluation.

Key words:soil liquefaction; liquefaction potential index; intensity measure (IM); pore pressure generation; seismic response prediction