Development of economic hybrid type liquefaction countermeasure for existing structure by combining pore water pressure dissipation method with continuous underground wall

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15086
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 22030:Geotechnical engineering-related
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: Morikawa Yukihiro 名古屋工業大学, 工学(系)研究科(研究院), 助教 (20710239)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 液状化対策 / 液状化 / 格子状地盤改良 / 間隙水圧消散工法 / 戸建て住宅 / 既設小規模構造物 / 模型実験

Outline of Final Research Achievements

In this study we investigated the economic hybrid type liquefaction countermeasure for existing structure that combines a floating grid type improvement method and the pore water pressure dissipation method. As a result of the study, it was found that the settlement damage of the structure due to liquefaction can be suppressed by the floating grid type improvement with a grid spacing of 1.2 to 1.4 times the width of the structure and an improvement depth of about twice the width of the structure. In addition, it was found that the floating grid type improvement with impermeable improvement body assuming general ground improvement could not reduce the inclination damage of structure, but the floating grid type improvement with drainage improvement body could reduce both settlement damage and tilt damage of structure.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

本研究によって，浮き型格子状地盤改良に間隙水圧消散工法を組み合わせたハイブリッド型液状化対策は既設構造物の沈下被害と傾斜被害の両方を低減できることが明らかとなり，傾斜被害の抑制には排水性改良体が重要であることも明らかとなった．従来の地盤改良工法では経済的に住宅などの既設構造物を液状化被害から守ることは困難であったが，本研究成果はその可能性を示し，国土強靭化に大きく貢献できると考えられる．