Kunihiro Watanabe

Evaluation of Sand Transport Control on Gravel-Sand Beach Using Groins with Low Crown Height

A numerical simulation of the beach changes on the Seisho coast was carried out using a contour-line-change model considering changes in the grain size. The applicability of the simulation model to a gravel-sand beach with protruding rocks was verified by comparing the calculated and observed changes after storm waves generated by T0709. The sand transport controls achieved by different types of coastal facilities were estimated and compared under an imaginary wave condition that could occur in future. A newly-designed groin with a low crown height was found to be most effective in preserving a straight coastline, if a sufficient amount mount of sand will be supplied by beach nourishment.

FIELD AND LABORATORY STUDIES FOR CONSTRUCTING GEOTEXTILE STRUCTURE ON HIGH-ENERGY JAPANESE BEACHES

Three geotextile structures were constructed on the Seisho coast, Japan. The size and design of each structure were investigated using a two-dimensional wave flume. The resistances to abrasion caused by coastal sediments were estimated with a newly developed accelerated abrasion test. These field and laboratory studies showed that geotextile structures are easy to construct and durable on the gravel-mixed Japanese coast.