Circularity Assessment of GeoBarrier System as Sustainable Retaining Wall

The growth of circular economy concepts has resulted in the need to develop methods for assessing circularity in geotechnical infrastructure systems. This paper proposes, for the first time, an initial framework for assessing circularity of geotechnical infrastructure systems and then uses it to assess the GeoBarrier System (GBS) as a case study. The framework considers five domains: water, energy, material, waste, and site quality. It was formulated based on a literature review, stakeholder requirements, and the case-specific characteristics of the GBS. Laboratory characterisation and numerical analyses were performed to assess the engineering performance of the system and support the circularity assessment. The results show that water circularity was the highest at 50.0%, meaning that half of the water in the system was effectively reused or recirculated. In contrast, energy circularity was absent due to the lack of renewable energy integration. Material and waste circularity performed at a moderate level, lower than water circularity, reflecting partial use of recycled materials and reuse of excavated soil. The site quality evaluation resulted in a score of 2.250, which, together with the other indicators, suggests an intermediate overall level of circularity performance. The assessment identified opportunities to improve circularity through greater on-site reuse of excavated waste, renewable energy integration, and improved site planning. The proposed framework is the first circularity/sustainability system specific to geotechnical infrastructure systems; therefore, apart from GBS, it is intended for potential applicability for evaluating circularity in other geotechnical systems.