Objective To achieve carbon reduction goals in urban infrastructure construction and to promote the implementation of the national 'dual-carbon' strategic decisions, based on the construction of Caozhunag Station, a two-level underground station on the Zhejiang section of the Shanghai-Suzhou-Jiaxing Intercity Railway, the scheme of continuous caisson method for underground station construction in soft water-rich soil regions is explored.

Method The characteristics of existing underground station construction schemes are analyzed. The continuous caisson method underground station construction scheme is introduced: the elongated station structure is longitudinally divided into multiple continuous monolithic caissons; jacking-sinking and underwater excavation techniques are adopted; once all monolithic caissons are fully sunk, they are connected longitudinally to form an integrated underground space. A 'structure first, sinking later' construction approach is employed, embedding the concept of 'integrating permanent and temporary works, green and low-carbon' throughout the design and construction process.

Result & Conclusion  Compared with the traditional cut-and-cover method, the continuous caisson method underground station construction scheme results in lower total carbon emissions throughout the construction process and a reduced proportion of emissions during the temporary enclosure stage, aligning more closely with the 'integrating permanent and temporary works' design philosophy. Using Caozhuang Station as an example, total carbon emissions are reduced by 3830.77 t CO₂e—equivalent to the carbon emissions from burning 1944.5 tonnes of anthracite. As an innovative, first-of-its-kind technology for underground station construction in China, the continuous caisson method offers significant potential for further development in low-carbon and emission-reduction applications, with opportunities for technical breakthroughs in the specialized design of caisson connection sections.