Reliability-Centered Foundation and Retaining System Assessment for Sustainable Infrastructure Delivery

Deep foundation and earth retaining systems are central to sustainable infrastructure delivery, yet their performance is highly sensitive to subsurface uncertainty, variable soil conditions, and construction quality risks. This study develops a reliability-centered framework that integrates geotechnical uncertainty modeling, structural performance analysis, lifecycle maintenance, and sustainability assessment for drilled shafts and retaining structures. The framework uses probabilistic models constructed from field data, construction records, and expert judgments, and applies Monte Carlo simulation and first-order reliability methods to estimate component and system probabilities of failure. Results show that subsurface uncertainty and correlation between components significantly affect reliability outcomes, and that there is an inverse trade-off between system reliability and environmental impact. The proposed multi-objective formulation allows designers to balance reliability, cost, and sustainability under different risk and sustainability goals. This work provides a practical decision-support tool for infrastructure designers and regulators, enabling more transparent and consistent choices in uncertain geotechnical conditions while accounting for lifecycle and sustainability constraints.