capacitive sensors for submersion and cavitation monitoring and suggestion of cavitation risk index

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420506
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geotechnical engineering
• Research Institution: The University of Tokushima
• Principal Investigator: Ueno Katsutoshi 徳島大学, ソシオテクノサイエンス研究部, 准教授 (70232767)
• Co-Investigator(Kenkyū-buntansha): TAKAHARA Toshiyuki 金沢大学, 環境デザイン学系, 助教 (20324098) ; SRENG Sokkheang 日本工営株式会社中央研究所, 総合技術開発部 地盤・材料グループ, 研究員 (10463572)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 空洞 / 護岸 / 支持力 / 地すべり / 静電容量型センサ / 閉回路レーダー / モニタリング / 有限要素法

Outline of Final Research Achievements

Sudden collapse of the hidden cavities occurs due to cyclic submersion and drainage history in earth structures, such as levees, quay walls, road embankments and pavements. A series of model tests of quay walls was conducted to clarify the sequence of cavitation from generation to collapse. Two monitoring methods using a couple of simple buried electric wires were developed: one was based on changes in capacitance of the coupled wires, and another was a kind of reflectmetry, called “closed circuit rader”. In-situ measurement of ground water level have been continued to compile data and knowledge for improvements of the developed monitoring system.
The influence of size and position of the cavities on the bearing capacity was examined by an elastic-perfectly plastic FE analysis. The diagram showing the relationships between the degree of deterioration of bearing capacity and size and position of the cavities were proposed.

Free Research Field

地盤工学