Impact of transport distance in life cycle assessments of geosynthetic reinforced soil walls

Abstract

A prevailing methodology to evaluate the environmental impact and subsequent sustainability assessment of structures is the life cycle assessment (LCA). In civil engineering, LCA methodologies allow for the quantification and evaluation of environmental impacts of comparable structures, considering different materials, processes, and manufacturing. For a valid comparison, structures must satisfy the same function or need. Regarding geotechnical engineering field, particularly for retaining structures, previous studies have shown the reduced environmental impact of reinforced soil walls (RSW) over solutions such as gravity or cantilever walls. RSWs are constructed with polymeric or steel soil reinforcement materials with different geometries (e.g., straps, grids, or sheets). Aside from a structural point of view, the selection of reinforcement can be of lasting impact, as geosynthetic materials can play an important role in meeting the United Nations sustainability goals regarding counting carbon mitigation and adapting to the impacts of climate change. The present work details the LCA of geosynthetic RSWs with concrete panel facings. Environmental impact assessments consider various wall heights, with special emphasis on the sensitivity to transport distances on the overall scoring, considering local and worldwide scenarios. Results show transport activities can be the second to third most impactful factor for RSW LCA.