Designing a Bored Tunnel for the Unthinkable-A Marine Vessel Collision Assessment

摘要

Bored tunnels are generally constructed underground to avoid surface features, whether manmade or naturally occurring. Designing a bored tunnel to avoid potential marine vessel collisions can be viewed as somewhat exceptional. The design of the Parallel Thimble Shoal Tunnel was one such case where engineers needed to find innovative, yet code compliant, design solutions for this unusual scenario. A codified probabilistic approach, intended to assess the vessel impact on bridges, in conjunction with empirical vessel collision test data, was used to calculate the vessel collision force. The integrity of the precast concrete segmental tunnel liner was then assessed using complex ground structure finite element modelling. The results of the analyses were compared against the owner's serviceability design state criteria and successfully verified.