Seismic risk assessment of underground structures under transient ground deformations

Abstract

Some relevant issues concerning the seismic risk assessment of underground structures under transient ground deformations are dealt with in this paper, mainly referring to: (i) the evaluation of earthquake-induced ground strains and the re-examination of the currently used formulas for design; (ii) the analysis of their spatial variability as a function of the lateral soil heterogeneities, including the role of surface waves; (iii) the ratio between shear and axial strains; and (iv) the main problems to be faced in the construction of hazard maps for seismic risk assessment of underground structures. A detailed example of application to the risk assessment of the water pipeline system in the town of Düzce, Turkey, is provided, including the numerical simulation of seismic wave propagation from the source of the Nov. 12, 1999, earthquake to the Düzce basin and the comparison of 1D and 2D results in terms of peak ground strains. The effect of different vulnerability functions on the risk assessment, either in terms of peak ground velocity or peak ground strain, is also addressed. Finally, a further example of risk assessment of the water transmission system in Thessaloniki is summarized. © 2007 Springer.