ABSTRACT
Reliability assessment is a widely-used tool to evaluate the performance of civil structures during their service lives. It provides a quantitative measure of structural safety level under a probabilistic framework, taking into account the uncertainties associated with structural resistance and the external load actions. The structural resistance (e.g., strength and stiffness) may deteriorate with time due to the impacts of environmental or operating factors. Moreover, the external load effects are often non-stationary on the temporal scale with time-variant characteristics in terms of occurrence rate and/or intensity. Under this context, the structural reliability would be dependent on the duration of the reference period of interest, known as time-dependent reliability. The characteristics of the random quantities can be described by probability distribution models, which can be calibrated through experimental or in-situ data. In cases where available data are limited (e.g., those regarding the deterioration process of structural resistance), some techniques such as the probability-bounding approach can be used to handle the imprecise variables. This chapter discusses the time-dependent reliability of aging structures subjected to imprecise deterioration information. First, the analytical methods for structural time-dependent reliability are introduced. Subsequently, a reliability-bounding approach is discussed, followed by two numerical examples to demonstrate the applicability of the reliability assessment methods.
