Relaxation processes of a thick granular layer at seismic slip rates

2016 Fiscal Year Final Research Report

• Project/Area Number: 25800257
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: KUWANO Osamu 国立研究開発法人海洋研究開発機構, 数理科学・先端技術研究分野, 研究員 (30511969)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 断層 / 粉体 / 摩擦構成則

Outline of Final Research Achievements

We conducted laboratory experiments designed to explore transient responses of a thick granular layer following a step change in slip velocity at seismic slip rates. Experiments were performed at constant normal stresses of 10- 30kPa using a ring shear apparatus with inner/outer diameters of 15mm/25mm. We measure the friction coefficient and thickness of glass beads layer at sliding velocities between 0.5 and 3 m/s. Experimental results show that the friction coefficient and layer thickness suddenly increases/decrease as sudden increase/decrease of sliding velocity and then exponentially decay to new steady state with characteristic slip length. We found that characteristic slip length is of the order of 10m. The response to a velocity step decreases simply symmetric to that to a velocity step increase.

Free Research Field

実験地震学