Research and exploration on building large urban underground space by small TBMs-multi-section undercutting and prefabricated component lining method

Abstract

With the growth of cities, the demands for building large underground space become increasingly intense. However, the traditional open-cut and undercut methods have certain limitations and are hard to fully satisfy the complicated boundary conditions of urban areas. For the purpose of a safer, more efficient, economical, and environmentally friendly development mode, by drawing on the merits of traditional methods and consider the development trend of smart construction and prefabricated structural application, we present a brand-new concept of building large urban underground space with small TBMs for multi-section undercutting and prefabricated component for lining, namely the Cut and Convert Method (CC Method for short). The main principle of the method is to divide a large underground space into small sub-units, and complete these units via subsection undercutting with small TBMs and prefabricated components; and then implement space and structure conversion to finally form a large integrated underground space. This paper introduces the overall idea and core principle of this method, illustrates the method in details by combining with the first application case, and discusses the application prospects and challenges. We hope to provide a new solution for developing large urban underground space.