Improvement on seismic behavior of rubble-mound breakwaters constructed on the liquefiable seabed

Breakwaters are built to create a safe area against the sea waves. Rubble-mound breakwaters are one of the most commonly used breakwaters if rock resources are available. The coastline in many parts of the world, including Iran, is composed of the loose granularwhich is prone to liquefaction. Given thatit is difficult to replace or improve seabed soil,an accurate understanding of the liquefiable bed and its impact on the performance of structures built on such bedding is important. The purpose of the present research is to develop an appropriate numerical model to evaluate the seismic behavior of rubble-mound breakwaters due to the liquefaction in the bed. Forthis purpose, it has been attempted to develop a numerical model by using FLAC software and Finn behavior model for liquefiable soil. Then, the behavior of a real breakwater on the liquefiable bed was investigated under a real earthquake record. Due to the high cost and difficulty of replacing or removing soil in deep water in order to decrease liquefaction damage, other solutions were investigatedTwo. simple methods were evaluated to decrease the deformation of rubble-mound breakwaters constructed on liquefiable seabed. It was observed that the addition of berm could decrease the settlement of the crest. Also, by decreasing the slope of the breakwaters, the crest settlement decreased.

Keywords:

Rubble-mound breakwaters , liquefaction , berm , numerical modeling , Finn model.