Life Cycle Assessment of Drilled Shafts

Abstract

Life cycle assessment (LCA) is a widely used methodology for quantifying environmental impacts associated with the life cycle stages of a system. LCA utilizes inventory of energy and materials to calculate the emissions from the life cycle stages and characterize the emissions into environmental impacts. LCA is applicable to complex systems like geo-structures, but its application in geotechnical engineering has been lacking because it is not mandatory in current practice. Given that geotechnical constructions involve land transformations through earthworks and construction of large-scale concrete and/or steel structures (e.g., bridge abutments, retaining structures, and tunnels), geotechnical engineering can play a vital role in sustainable development by ensuring that the resources are consumed responsibly with minimal emissions to the environment. LCA can help designers determine the most environment-friendly option among design alternatives. It can also help in optimizing designs by varying the parameters that affect the environmental impacts or emissions of interest. In this paper, the process of performing LCA is described with drilled shaft foundations as examples. Sample calculations related to the quantification part of LCA are provided, and sample results are interpreted to demonstrate the usefulness of information obtained from LCA.