The Role of Sustainability in Target Reliability Assessment

This research focusses on the effects of including sustainability factors in determining the target reliability of a structure. Target reliability is a measure of structural performance, and whose values depend on the costs of increasing safety together with economic, societal, and environmental consequences of failure. With the advent of climate change, structural performance must be complemented by appropriate sustainability levels. Structural standards, particularly in South Africa, have received minor to no updates with regards to sustainability. Sustainability is measured in terms of economic, social, and environmental aspects further classified by the Life Cycle Cost Analysis, the Life Quality Index, and Life Cycle Assessment respectively. The research methodology is based on the fib Model Code where indicators are proposed to assess performance criteria such as sustainability. However, as no values for these indicators have been determined, this research aims to determine benchmark values for the evaluation of sustainability parameters. Three methods which entail the Environmental Priority Strategy, the Panel and No Effect Level methods, will be considered in the quantification of indicators. This study considers the serviceability limit state (SLS), complementing a wider research project aiming to determine suitable SLS target reliabilities. Reliability models for two cases where serviceability requirements govern the design, namely, a bridge and a water retaining structure, will be developed. The sustainability framework will be integrated into the reliability model through probabilistic analysis. This will enable the impact of sustainability indicators on determining the target reliability of a structure to be modelled in a developing country’s context.