FIELD VERIFICATION ON THE OVERFILL RATIO OF BEACH NOURISHMENT CONSIDERING GRAIN SIZE DISTRIBUTION

Abstract

 The applicability of James' method, which can calculate the overfill ratio of beach nourishment in consideration of the grain size of borrow sand and native sand, to beach nourishment in the coast of Japan has not been verified. In this study, we verified the applicability of the James’ method to the Kineicho construction area in the Niigata coast and the Hamamatsu Shinohara coast in Shizuoka prefecture, where beach nourishment was carried out, and conducted sensitivity analysis on the overfill ratio of the amount of beach nourishment with respect to the particle size distribution of the borrow sand. The results showed that the James’ method can be used in setting the amount of beach nourishment in the coast where changes in soil volume due to longshore sediment transport can be ignored, and that attention should be paid to the rapid increase of the overfill ratio in the case that the standard deviation of the grain size of borrow sand is smaller than that of native sand.