Life Cycle Assessment of Underground Car Park Retaining Walls

This report article presents a life cycle assessment (LCA) of retaining walls within the excavation pit of an underground car park associated with an office building in Berlin, Germany. The study evaluates the environmental performance of four structural alternatives over a service life of 50 years. The alternatives assessed include permanent steel sheet piles, temporary steel sheet piles with a permanent reinforced concrete wall, permanent concrete secant piles, and permanent concrete diaphragm walls. The LCA follows the life-cycle framework outlined by EN 15798, covering the product stage, construction process, repair, end-of-life, and benefits and loads beyond the system boundary. The assessment is based on environmental product declarations in accordance with EN 15804+A2 and meets ISO 14044 requirements. The findings aim to support construction professionals in decision-making by providing comparative insights into the environmental impacts of different retaining wall systems.