BIM-enabled carbon accounting and integrated design of underground infrastructures

The underground infrastructure construction has lacked progress towards decarbonization and sustainability due to inconsistency of practice, uniqueness of ground conditions, and independency of disciplines, urging to transition the way we design, construct, and operate tunnels. This paper reviews current internationally accepted guidelines of carbon accounting methodologies, namely the module-based method from EN 15978 and the scoped-based method from Greenhouse Gas Protocol, then seeks to digitally implement these methods to account emissions sources in tunnelling, enabled by parametric modelling in Building Information Modelling (BIM) with a case study of prefabricated station. Furthermore, to fundamentally integrate carbon assessments with geotechnical design, a multiobjective optimization algorithm is implemented to generate the optimal solutions resolving the conflicted goals of stability and carbon reductions for TBM tunnel support design. This paper proposes a BIM-enabled carbon-integrated design workflow for underground infrastructures.