| Accounting for waterway vessel collision is an integral component of structural design for any bridge spanning a navigable waterway. Each time a vessel traverses a given waterway, there exists an associated risk that the vessel will become aberrant from the intended transit path, and once aberrant, will strike a nearby bridge structural component. During collision events, massive waterway vessel groups, such as barge flotillas, are capable of dynamically transmitting horizontal forces to impacted bridge components such as piers. Furthermore, such collision-induced forces can be sufficient to cause collapse of piers or roadway spans in the vicinity of the impact location. If collapse takes place, economic loss is suffered due to subsequent traffic rerouting and bridge replacement costs. Additionally, fatalities may occur if the roadway is occupied during or shortly after the collapse event. The research presented here focuses on the development of probability of collapse expressions for bridge piers subject to barge impact loading, where such relationships are integral to current bridge design methodologies. Expression development is facilitated by employing probabilistic descriptions for a multitude of random variables related to barge traffic characteristics and bridge structures in conjunction with nonlinear dynamic finite element analyses of barge-bridge collisions. High levels of efficiency, achieved through use of advanced probabilistic simulation techniques, are necessarily incorporated into the barge-bridge collision analysis framework to allow feasible obtainment of structural reliability parameters. Through joint use of efficient probabilistic simulation and vessel collision analysis techniques, the probability of collapse---and furthermore, the proximity to applicable structural limit states---are quantified for a representative set of bridges. The structural reliability parameters are then, in turn, used to form structural collapse relationships that aid in the design of bridges subject to barge collision. |
