TITLE:
Earthquake Fragility Assessment of the Underground Tunnel Using an Efficient SSI Analysis Approach
AUTHORS:
Thai Son Le, Jungwon Huh, Jae-Hyun Park
KEYWORDS:
Soil-Structure Interaction, Maximum Likelihood, Fragility Curves, Dynamic Analysis
JOURNAL NAME:
Journal of Applied Mathematics and Physics,
Vol.2 No.12,
November
25,
2014
ABSTRACT: This paper represents a simplified seismic
fragility analysis approach of the underground tunnel structure in consideration
of the soil-structure interaction (SSI) effect. SSI effect founds to be essential
in the estimation of dynamic analysis of underground structures like tunnels
and thus needs to be considered. The ground response acceleration method for
buried structures (GRAMBS) known to be a very efficient quasi-static method
that can consider SSI effect is used in the proposed approach to evaluate
seismic structural responses without sacrificing much accuracy. Seismic
fragility curves are then developed by applying the maximum likelihood
estimates (MLE) to responses of a large set of artificial ground motion time histories
generated for multiple different levels of earthquake intensity. It is also
assumed in this paper that the seismic fragility curve can be represented by a
two-parameter lognormal distribution function with median and log-standard
deviation that need to be defined using MLE.