Prefabricated UHPC-concrete-ECC underground utility tunnel reinforced by perforated steel plate: Experimental and numerical investigations

In this study, perforated steel plate-reinforced utility tunnel with the use of ultra-high-performance concrete (UHPC) and engineered cementitious composite (ECC) was proposed. The mechanical performance of the composite utility tunnel was experimentally investigated, and the cracking behavior and failure process were analyzed based on the digital image correlation (DIC) technique. It was found that the crack-control (durability) performance of the composite utility tunnel was superior to that of concrete utility tunnel with the same reinforcement ratio, and the composite utility tunnel can be used in severe corrosive environment. Additionally, the composite action between perforated steel plate and ECC was evaluated based on direct tension test and DIC analysis. Finite element (FE) analysis was conducted on the perforated steel plate-reinforced ECC and composite utility tunnel for a comprehensive understanding of the mechanical behaviors. The findings of this study provided useful knowledge for the design and application of the proposed composite utility tunnel for underground construction.