Digital Twin Aided Sustainability and Vulnerability Audit for Subway Stations

Digital twin (DT) or so-called ‘building information model (BIM)’ has brought great revolution to the current building industry. Its applications to life cycle management of buildings and infrastructures can further increase the social and economic benefits. As a complete information model, a digital twin integrates the information of a project from different stages of the life cycle into a model, in order to facilitate better asset management and communicate through data visualizations with participants. This paper unprecedently introduces a digital-twin aided life cycle assessment to evaluate a subway station. Dadongmen subway station in Hefei was used as a case study. This new study benchmarks the cost estimation and carbon emission at each life cycle stage of the project. The cost in the construction stage of the project is the highest, accounting for 78% of the total cost. However, the amount of carbon emissions in the operation and maintenance is higher than the amount during the production of building materials, accounting for 67%. Among them, concrete only accounts for 43.66% of the carbon emissions of building materials, even though concrete was mainly used for constructing the metro station. Steel bar and aluminum alloy have carbon emissions of 29.73% and 17.64%, respectively. In addition, emerging risks of the subway stations can be identified. The digital twin has been used to illustrate vulnerability and potential solutions to emerging risks, and to assess the suitability through life cycle cost and carbon footprint. This initiative is relatively new to the industry. The new insight into life cycle assessment or LCA (especially carbon footprint over the life cycle) integrated with digital twin applications will enable sustainable development that will enhance resilience of metro railway systems globally.