Dynamic analysis of precast ultra-high performance concrete tunnel under internal explosion

Underground structures hold great significance in the infrastructure of modern society. With the rapid construction of such facilities, the possibility of explosions occurring inside these structures due to unforeseen accidents or deliberate acts cannot be ignored. Past catastrophic events have demonstrated the necessity of implementing anti-blast design for underground structures, particularly in vulnerable locations. This promotes investigations into the behavior of underground structures subjected to internal explosions. For the first time, a thorough simulation model is developed using the multi-material Coupled Eulerian–Lagrangian approach to examine a full-scale precast ultra-high performance concrete (UHPC) tunnel under internal explosion. The precast tunnel structure closely resembles real construction configurations. The simulation model takes into account the simultaneous interaction between the tunnel and the surrounding soil. The accuracy of the suggested simulation model is validated against experimental results. For various explosive charge weights, tunnel lining thicknesses, materials, and tunnel shapes, extensive parametric simulations are conducted. Results obtained highlighted UHPC's superiority as a substitute for conventional concrete due to its strong blast-resistant capacity. The findings from this research also shed light on the precast UHPC tunnel's structural response to an interior explosion, that can assist designers and managers choose the best design for blast protection.