Laboratory Study on Frictional Behavior of Rock Blocks of Meter Scale. Methods and Preliminary Results

Autor: G. G. Kocharyan, A. A. Ostapchuk, D. V. Pavlov, G. A. Gridin, K. G. Morozova, J. Hongwen, I. A. Panteleev
Rok vydání: 2022
Předmět:
Zdroj: Izvestiya, Physics of the Solid Earth. 58:929-940
ISSN: 1555-6506
1069-3513
DOI: 10.1134/s1069351322060064
Popis: —The paper introduces a new, unique for Russia, meter-scale laboratory setup created in the Institute of Geosphere Dynamics of the Russian Academy of Sciences (IDG RAS) to study the development of different sliding regimes on rock discontinuities. The experimental procedure is described and the results of the first series of tests aimed at studying the formation of different sliding regimes on rock faults are presented. The laboratory fault was a loaded contact of two 75-cm long blocks made of diabase. The fault was filled with granular material (a fault gouge). Normal stresses on the fault can reach 10 MPa. By varying fault gouge composition and loading rate, we reproduced a wide range of sliding regimes: sliding with constant velocity, regular stick-slip, and aperiodic slow slip episodes. It is shown that a variation in the loading rate can cause a significant change in the sliding regime. Intense frictional crushing of gouge grains is detected in the experiments at relatively low normal pressure of 2 MPa. In the case of high-amplitude stick-slip, besides crushing of the gouge material, also structural phase transformations of quartz grains corresponding to a local temperature increase up to 700°C are revealed. A possible set of the problems related to deformation processes in seismogenic fault zones that can be addressed by modeling on such setups—the pre-seismic stage of inelastic behavior of the main fault zone at critical stress—is outlined.
Databáze: OpenAIRE
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