Objectives :
Pre-damage the Nojima and Soultz granitoids to be able to perform flow-through experiments [T2.3, T2.4]

Description of planned work :
Samples of length 20 mm and ∅ 20 mm will be pulverized using the Split Hopkinson Pressure Bars of ISTerre. This high-strain rate device records mechanical data at strain rate higher than 100/s. At high strain rate, strain localization is inhibited and several fractures developed simultaneously [1], creating a pervasive fracture network and a significant surface area to enhance alteration reaction. Dynamic damage has been suspected to occur in the Nojima fault.

The generated pulverized samples will X-ray CT scanned and their Vp/Vs properties measured before being circulated to ISTerre and GM for flow-through experiments [T2.3, T2.4].

The protolith samples are to scarce to conduct a systematic study of the high-strain rate transition to pulverization, yet the microstructural studies between dynamic damage of both fresh and altered monzonite from Soultz will provide insight of the effect of alteration on the dynamic damage of rocks.

Updated on 1er avril 2024