Structural Response of a Prefabricated Utility Tunnel Subject to a Reverse Fault

Prefabricated utility tunnels have drawn much attention in relation to rapid urban development. On this, how to maintain the integrity of an underground lifeline, which is subjected to unexpected fault displacement action, is a concern either from the design or the construction aspect. By applying the commercial software program ABAQUS, this paper presents a systematic numerical simulation of a prefabricated utility tunnel affected by a reverse fault. The critical parameters investigated in this study include fault displacement, burial depth, utility tunnel-soil friction coefficient, and the angle of the utility tunnel crossing the fault plane. Results of the numerical modeling revealed that: (1) both the overall structural deformation and the spliced joints deformation of the prefabricated utility tunnel increase with increasing fault displacement, which greatly reduces the waterproofing ability of the utility tunnel joints; (2) the opening displacement of the joints on the roof of the utility tunnel near the fault plane is positively correlated with burial depth, but the variation is slight; (3) the variations in utility tunnel-soil friction coefficient have little effect on the overall structural deformation and the spliced joints deformation; (4) the opening displacement of the spliced joints of the utility tunnel basically gradually increases with an increase in the crossing angle near the fault plane, which is different than when it is away from the fault plane. The main outcomes obtained from this study can provide reference for the construction of prefabricated utility tunnel in fault active area