Zero-carbon tunnel: Concept, methodology and application in the built environment.

Road tunnels are key components in the transportation infrastructure system, and plays a key role in the carbon emission. At present, the research on tunnel carbon emissions is still at an early stage, and its research target has not yet realized the transformation from low-carbon to zero-carbon. Therefore, this paper proposes the concept of the zero-carbon tunnel and introduces a methodology for zero-carbon tunnel design. This methodology includes defining the accounting boundaries of a zero-carbon tunnel, establishing a tunnel life-cycle carbon emissions assessment model, and verifying the zero-carbon tunnel. The methodology is applied to a road tunnel in China, to assess its carbon emission level and explore pathways to achieve zero-carbon status. Additionally, this paper discusses issues related to zero-carbon tunnels and explores future research prospects in this area. This study provides a reference for subsequent research on road tunnel carbon emissions. [ABSTRACT FROM AUTHOR]