Deformation mechanism of the tunnel lining due to the deterioration of surrounding ground and the reflection on the tunnel design

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04594
• 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: Yokohama National University
• Principal Investigator: CUI Ying 横浜国立大学, 大学院都市イノベーション研究院, 准教授 (60583797)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 劣化 / 長期安定性 / 地震時挙動 / 膨潤性 / 内部侵食

Outline of Final Research Achievements

In this study, the long-term stability of tunnels caused by the deterioration of ground materials and the impacts of deteriorated areas on the seismic behavior of tunnels were investigated, and the following findings were obtained.
(1) The stress acting on the tunnel lining increased significantly with swelling of the ground, and the distribution is also changing significantly. (2) The seismic behavior of the tunnel during earthquakes was found to change significantly due to the local strength loss associated with the deterioration of the ground. (3)The internal erosion, as well as high velocity, is easy to happen at the soil-lining boundary, which is mainly caused by the short flow path and the gap.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

本研究では，地山の経時劣化がトンネルの常時，地震時の安定性に及ぼす影響について明らかにした．特に劣化過程を再現した浸透模型実験および二次元振動台実験により得られた知見は，劣化に伴う地盤材料の変化を忠実に反映できている．
一方，本研究はトンネルのマネージメントにおいて，覆工コンクリートの劣化だけでなく，地山の劣化について着目し，それらの影響を反映するものである。地山の劣化からトンネルの安定性までの一連の繊細な検討，および地盤劣化の観点をトンネルの設計・補修に取り入れることにより，トンネルの安全な運用に大きく貢献できると考える。