Carbon Footprint and Seismic Fragility Assessment of a Bridge–Foundation–Ground System Using Stone Columns as Liquefaction Countermeasures

Abstract

Sustainability has emerged as a paramount concern in the construction and development of built infrastructure. This study delves into the environmental impact and vulnerability of an idealized bridge–foundation–ground system using stone columns as a liquefaction countermeasure, focusing on the seismic response in the transverse direction. For that purpose, a nonlinear three-dimensional (3D) finite element framework is established, exploring the influence of stone columns on the vulnerability of the bridge–foundation system. To enhance the reliability of the analysis outcomes, an optimal intensity measure is identified through comprehensive evaluations of efficiency, correlation, coefficient of variation, and sufficiency. Further, systematic assessments of total cost and carbon emissions associated with ground improvement are performed using three different life-cycle assessment (LCA) approaches, including process-based LCA (P-LCA), economic input–output LCA (EIO-LCA), and a hybrid approach that combines P-LCA and EIO-LCA. The results demonstrate that stone columns noticeably reduce liquefaction-induced damage to pile foundations, proving their effectiveness in improving seismic resilience. While several factors influence overall ground improvement design (such as material availability and demobilization), the overall analysis techniques and derived insights systematically quantify sustainability, thereby offering an additional dimension in decision-making when implementing such liquefaction mitigation techniques in seismic-prone regions.