ABSTRACT
The sustainability rating of subterranean transit infrastructure is contingent on the degree of alignment with established sustainability criteria. The intricacies of individual projects and their contextual environmental considerations significantly impact sustainability rating. Utilizing a comprehensive evaluation framework like Building Research Establishment Environmental Assessment Method (BREEAM), alongside strategic interventions to minimize ecological footprints, has proven instrumental in attaining elevated sustainability scores. Generalizations are challenging due to the variable significance of factors such as energy, water, pollution, etc., which are contingent on the specific attributes of each project, its geographical location, and the pertinent local environmental considerations.
Furthermore, the extraction of geothermal energy in underground infrastructure saves energy and minimizes carbon emissions. Tunnels and subsurface infrastructures can function as geothermal exchangers, with temperature variation with depth being critical. The extent of function is influenced by various factors including the physical properties of the ground, surface coverage, and presence of water-bearing strata. The use of such geothermal strategies may improve environmental impact and reduce the project’s carbon footprint significantly. The project’s sustainability score may influence project planning and decisions for future management.
This article discusses geothermal energy applications for concrete segmentally lined tunnels and includes discussion of a 2D FE Plaxis analysis for conceptual assessment of tunnel impacts, and a computational sustainability case study applying the BREEAM method to a hypothetical Toronto Metro Subway tunnel employing a thermal geo-structural approach. Overall, taking into account the manageable structural side effects of geothermal application, this is an innovative approach that achieves a high level of sustainable energy and decreases carbon impact.
