地盤の年代効果と微地形の空間分布を考慮した高度な液状化危険度評価手法の開発

2013 Fiscal Year Annual Research Report

• Project/Area Number: 13F03363
• Research Institution: The University of Tokyo
• Principal Investigator: 清田 隆 東京大学, 生産技術研究所, 准教授
• Co-Investigator(Kenkyū-buntansha): POKHREL Rama Mohan 東京大学, 生産技術研究所, 外国人特別研究員
• Keywords: 液状化 / GIS / 地盤沈下 / DSM / 東北地方太平洋沖地震 / ハザードマップ

Research Abstract

The study was focused on the liquefaction and subsidence induced in the Urayasu area by 2011 Off the Pacific Coast of Tohoku Earthquake (M=9.0). Boreholes in the Urayashu area were collected and the liquefaction potential was calculated at the borehole locations. The liquefaction potential at the unsampled locations were estimated by using geostatistical methods. For the ground subsidence the LiDAR (Light Detection and Ranging) images before and after the earthquake were collected and analyzed the spatial distribution of soil subsidence within the studied area. Now we are trying to find the relationship between liquefaction potential and subsidence in the reclaimed area.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

限られた地盤データに基づく液状化の発生予測の高度化に関する試みに加え、液状化により発生し得る地盤沈下についても液状化指数と関連付けてGIS上で表現できるよう、作業を進めている。研究開始からの期間が短いため研究発表はまだないが、研究は順調に進展していると言える。

Strategy for Future Research Activity

To obtain the accurate relationship between liquefaction potential and ground subsidence, the software Global Mapper will be used to analyze LiDAR images for ground subsidence, and software Arc GIS will be used to analyze the liquefaction potential. Based on these analyses, the rational relationships between the liquefaction potential and ground subsidence will beestablished. Similarly, the effectiveness of the soil improvement methods used in the past in liquefied area will be analyzed.