Digital twin-based quantification of carbon emission from foundation pit construction: A case study of a station in Shanghai Metro

Abstract

This study focused on achieving the carbon peaking and carbon neutrality goal. A carbon emission calculation method based on the entire process of excavation construction and the emission factor method for the foundation pit construction of a metro station was proposed. This method facilitated quantitative calculation of total carbon emissions in metro foundation pit engineering, which was then incorporated into a self-designed digital twin platform to drive sustainability efforts. The proposed calculation approach was verified in the foundation pit of Huangpi South Road Station (Shanghai Metro Line No. 14). (1) The pit construction process of the targeted metro station emitted 127,439t of carbon dioxide equivalent. (2) From the material perspective, reinforcing steel and concrete accounted for a significant proportion of the overall carbon emissions. Whereas, from the construction perspective, the engineering process of supporting structures accounted for a considerable proportion of the carbon emissions. (3) A comparative analysis of different construction zones revealed that the carbon emissions during the construction stage of the metro pit project were closely related to the amount of earthwork and size of the deep excavation engineering. Practically, the discovered knowledge of carbon emission characteristics can be visualized in a digital twin.