Mechanical performance of a prefabricated subway station structure constructed by twin closely-spaced rectangular pipe-jacking boxes

Traditional open-cut and cast-in-place construction methods for subway stations result in significant social and environmental problems, failing to meet green construction and sustainable development requirements. The pipe-jacking method could solve these problems, with the advantages of mechanised trenchless construction and prefabrication. Based on the engineering project of the Shasan station of Shenzhen Rail Transit Line No. 12 in China, a novel structure scheme of the subway station constructed by the pipe jacking method are discussed, including structure segmentation, joint design, longitudinal connections, waterproofing, and construction pro-cedures. Subsequently, the specimens were tested under twice the values of the designed loads to obtain the bending resistance and shear resistance characteristics of the joint. Moreover, a simplified solid element section -spring model for mimicking the behaviour of the joint was established and validated by the test results. The mechanical performance of the station structure was investigated using three-dimensional finite element ana-lyses by incorporating a simplified joint model. The results indicate that the structure deformation and stress meet the code requirements, demonstrating the applicability of the novel structure scheme. The research pro-vides a practical solution for the trenchless construction of prefabricated subway stations, contributing to sus-tainable development of urban underground space.