Chávez Cárdenas, X. and Kobayashi, N., 2017. Movement of wooden blocks on ground and pilings in swash zone. In: Martinez, M.L.; Taramelli, A., and Silva, R. (eds.), Coastal Resilience: Exploring the Many Challenges from Different Viewpoints. Journal of Coastal Research, Special Issue No. 77, pp. 7–18. Coconut Creek (Florida), ISSN 0749-0208.
Time-varying interactions among storm surge, waves, sand beaches, and wooden houses determine the degree of damage to the houses on low-laying beaches but the complicated damage process is not well understood. An exploratory laboratory experiment consisting of eight tests was conducted in a wave flume with a sand beach to examine the movement of ten wooden blocks (idealized houses) on the foreshore and berm as well as on short and long pilings. The still water level was varied to create accretional and erosional profile changes on the foreshore and berm. The cross-shore wave transformation on the beach and the wave overtopping and overwash of the berm were measured in 71 runs of 400-s each. The initial block elevation above the sand surface is shown to have little effect on the hydrodynamics, sediment transport, and profile evolution in this experiment with widely-spaced blocks. The block floating and sliding on the sand surface and block falling from the pilings depended on the swash hydrodynamics and block clearance above the foreshore and berm whose profile varied during each test. A probabilistic model is developed to estimate the wetting, sliding, and floating probabilities for the block in the swash zone using the water depth measured in the vicinity of the block. The estimated probabilities are used to explain the observed block floating and falling.