Determination of Accidental Actions for the Remaining Lifetime of Bridges

Existing bridges have sometimes to be evaluated considering ship impact. Using present codes for accidental actions would often lead to rehabilitation measures or to new structures which might not be efficient regarding the rareness of the serious ship collision events to bridges. Therefore a method has been developed to determine ship collision forces as time-dependent action for the remaining lifetime of an existing bridge. This method, called remaining life expectancy concept, is based on the design concept of the Eurocodes which is a reliability-based design procedure. It considers the principles of the common maintenance strategies and allows the safe and economic verification of existing bridges considering their experienced lifetime. The contribution explains the methodology of modern ship impact determination by combining a load model with a probabilistic model as it is used for the design of new bridges. The adaption to remaining lifetime adapted dynamic impact forces is shown.