Fragility of Floating Docks for Small Craft Marinas

Abstract:

Because of the damage resulting from the 2010 Chile and 2011 Japanese tele-tsunamis, damage to the small craft marinas in California has become an important concern. This paper will explain the methodology and results used to simulate the demand and also the structural capacity of the floating dock system, composed of floating docks, fingers and moored vessels during tsunami events. The intent is to develop a predictive tool to understand the vulnerability of California’s small craft harbors to tsunami events. To validate the methodology, the probabilistic model will be applied to Santa Cruz Harbor. Maps of maximum velocity and mean current direction from the 2011 Japan tsunami have been developed using a numerical model. Cleat and pile guide locations will be recorded and georeferenced from aerial images before the event. The fragility curves for each dock/finger system will be compared with damage reports and aerial images from just after the tsunami event. A discussion of how the fragility curves compare with the damage reports will be included.

It is anticipated that these curves will be useful to marina operators to use as a tool to determine where rehabilitation might be necessary to mitigate some of the damage from the next event. Conclusions will focus on how results can be used by marina operators to reduce harbor vulnerability to tsunamis.