Steel and reinforced concrete buildings are popular structural systems. The design of these buildings is regulated by deterministic building codes. In this context, it is established that if building codes are followed, the structure will resist demands without collapsing. However, no regulation is required to control the damage of structures in terms of performance criteria. In this paper, the seismic performance and structural reliability of both steel and reinforced concrete buildings, respectively, are analyzed as a benchmark case of study. Both buildings are designed in an earthquake-prone area for two soil types, respectively. Subsequently, nonlinear dynamic analyzes are conducted and the seismic responses of the models are determined in terms of inter-story drift. To obtain seismic responses, eleven characteristic ground motions of the region are selected corresponding to three performance levels: (1) immediate occupancy, (2) life safety, and (3) collapse prevention, respectively. It was documented that the resulting maximum inter-story drift was much lower than the one obtained from modal analysis. In addition, the risk was computed in terms of reliability index integrating a novel probabilistic approach with performance-based design criteria. According to the results, a small variation in the structural risk among the buildings under consideration is observed. However, buildings designed for rigid soil proved to be more reliable. Additionally, it is observed that the buildings designed with current regulations are too conservative based on the performance criteria limits. Hence, structures located on earthquake-prone areas may be overdesigned when implementing deterministic building codes.

For offshore platforms installed in seismically active regions, maintaining the safety of operations is an important concern. Therefore, the reliability of these structures, under earthquake ground motions, should be evaluated accurately. In this study, reliability methods are applied to determine the probability of failure of jacket platforms against extreme level earthquake (ELE), considering uncertainties in ground motions and the properties of the structure and soil. They are verified by two variance reduction Monte Carlo sampling methods to find the most efficient method in terms of both accuracy and calculation time. During the ELE event, also called strength level earthquake, structural members and foundation components are permitted to sustain localised and limited nonlinear behaviour, so a force-based criterion is utilized for the limit-state function. The results indicate that all reliability methods, except for FOSM, provide a good approximation of the probability of failure. Also, Point-fitting SORM is the most efficient 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.