Settlement prediction and design optimization of peat ground improved by integrated pre-loading method

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K04607
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22030:Geotechnical engineering-related
• Research Institution: Akita National College of Technology
• Principal Investigator: Yamazoe Nobutaka 秋田工業高等専門学校, その他部局等, 准教授 (60760238)
• Co-Investigator(Kenkyū-buntansha): 西村 聡 北海道大学, 工学研究院, 教授 (70470127) ; 荻野 俊寛 秋田大学, 理工学研究科, 准教授 (80312693)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 泥炭 / プレロード工法 / 長期沈下

Outline of Final Research Achievements

The purpose of this study is to develop an analsis tool that can predict the consolidation behavior of peat ground improved by the preloading method. For this purpose, systematic laboratory tests were conducted, the results were modeled using isotach low and critical state theory, and implemented in a finite element method program. The laboratory tests were simulated using the developed analysis tool, and the reliability of the analysis method was confirmed by comparing the measured values. Analsis was also peformed on peat ground improved by the vacuum consolidation method, and it was found that the in-situ behavior was well reproduced. In addition, design example regarding optimization of the improvement effect was presented through parametric study.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

事前に圧密促進を図るプレロード工法はコストが安価で、関東以北に広範囲に分布する超軟弱土の泥炭地盤においても一般的に用いられるが、供用中の長期沈下によって上部構造物に機能損傷が生じる可能性がある。本研究は供用中の地盤変状を力学理論に基づき予測する新たな汎用解析ツールを開発したものである。従前、長期沈下は過去の計測結果から経験的な方法により予測がなされていたが、開発したツールでは不均一性の考慮など解析条件に関する自由度が高く、また複数の工法との組み合わせにより多様化が進むプレロード工法に対しても導入が容易である。また、改良仕様の最適化への寄与が期待される。