Bifurcation processes to shear-localization and unstable behavior of rock

2014 Fiscal Year Final Research Report

• Project/Area Number: 25610150
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Geology
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: TAKAHASHI Miki 独立行政法人産業技術総合研究所, 活断層・火山研究部門, 研究員 (40470033)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 歪集中 / 平面歪試験 / 回転せん断試験 / 摩擦構成則 / 分岐現象

Outline of Final Research Achievements

Here we assumed that processes to unstable behavior of rock, which induces huge earthquake, will be began from selection and localization of shear in rock system. Based on this hypothesis a goal of this study is to denote possible measureable phenomena we will have in nature.
We planned and carried out two types of experiments; one is plane shear test on halite board, another is rotary shear test for halite powder. For the plane shear test, we started to construct new, observation-available machine for deformation on the halite board. For the rotary shear test, we determined deformation parameters of the halite-muscovite mixture using velocity step change tests. Those deformation parameters showed history dependences, which might be caused both by what matured structure developed in halite specimen and by localization.

Free Research Field

岩石力学