Extended equivalent linear model (X-ELM) to assess liquefaction triggering: Application to the City of Urayasu during the 2011 Tohoku earthquake

摘要

This paper proposes a hybrid iterative approach to evaluating the liquefaction potential and settlements when liquefaction is not triggered for a saturated sand deposit subjected to seismic motion. The proposed method is a combination of an equivalent linear dynamic analysis and an empirical pore pressure build-up model. The two concepts are combined to account for the increase of pore-water pressure in the dynamic response. This extended equivalent linear model, or X-ELM, introduces a parameter v identified by means of an extensive set of computations and observations. The approach has been validated in the case of Urayasu City during the 2011 Great East Japan Earthquake. The X-ELM enables the assessment of the triggering of the soil liquefaction of 12 representative soil profiles, namely, four profiles representing non-liquefied grounds in the old town of Urayasu and eight profiles representing the liquefactionprone grounds in the reclaimed area of the city. The X-ELM computed areas of triggered liquefaction or non-liquefaction are found to be in good agreement with qualitative observations and in-situ measured responses. (C) 2019 Production and hosting by Elsevier B.V. on behalf of The Japanese Geotechnical Society.