河川・水理構造物 (2)

[II-148] Investigation on structure and arrangement of gravel bags for erosion protection at the end of a groundsill

*福田 朝生¹、澁谷 慎一²、福岡 捷二¹ (1. 中央大学研究開発機構、2. 国土交通省関東地方整備局京浜河川事務所)

Keywords:gravel bag, mudstone, erosion protection, structure, arrangement, solid-liquid multi-phase simulation

A new numerical technique assessing stability of gravel bags in flows was developed. Using the technique, we investigated effective structure and the arrangement of gravel bags for the erosion protection at the end of a groundsill in the Tamagawa River where mudstone was exposed. It was shown that the structure in which a gravel bag divided into small bags was wrapped in a large bag was effective for the stability of them. In addition, it was important to install gravel bags integrally downstream from the groundsill to the region where the high flow velocity on gravel bags was decelerated.