Seismic performance evaluation of a metro station structure under multi-source random conditions based on probability density evolution method

Ground motion, geotechnical materials, and structural materials are three primary uncertainty sources in the seismic design and assessment of metro station structures. However, the effects of the latter two have often been ignored, which brings doubts about the rationality of the design and evaluation results. In this paper, based on the probability density evolution theory, the non-linear stochastic seismic analyses and reliability analyses under multi-source uncertainty conditions were carried out for a metro station structure in soft soils, and the effects of three primary uncertainty sources, i.e., ground motion, geotechnical materials, and structural materials, were explored. Random variable models were established to quantify the involved uncertainties of non-linear materials. The results showed that for underground structures, the uncertainty of geotechnical materials is nonnegligible, because it not only changes the soil-structure relative stiffness, but also changes the deformation mode of strata, resulting in both an increase in the elastic reliability and a decrease in the elastic-plastic reliability. The uncertainty source of structural materials changes the soil-structure relative stiffness, but has little effect on the lateral deformation response and elastic-plastic reliability of the station structure. © 2024 Published by Elsevier Ltd.