浸透流解析を用いた簡易的なパイピング進行評価手法の堤防模型実験への適用性検討

抄録

In 2012, the Yabe River levees broke down due to the occurrence of piping penetration from the foundation ground. The purpose of this study is to establish a pipe-progression evaluation-method. A pipe-progression in a levee foundation was evaluated using a seepage analysis which modeled formation progress of a pipe. As a result, it was confirmed that the local hydraulic gradient at the end of the pipe changed by the length of the pipe and the tendency of this change depended on the hydraulic conductivity of the pipe. It is considered that pipe-progression becomes slow and eventually suspended in case of a reduction of a local hydraulic gradient. Some levee-model-experiments were conducted to confirm that the stop of the pipe progression was a possible phenomenon. It was observed that the pipe-progression stopped at certain water levels in these experiments. Therefore, the reproduction of the phenomena proved the applicability of the evaluation approach.