Rate Effects on Shear Deformation of Rough Limestone Discontinuities

Shear strength testing of consolidated claystones: breakpoint detection of shear stress versus shear displacement curves, a statistical approach

“…The detection of changes in the characteristics of shear stress and shear displacement curves is of increasing importance in the process of so-called multi-step analyses (Muralha 2012;Muralha et al 2014), in which multiple loading levels are determined with the use of one sample (Morad et al 2019). The load levels have to be changed prior to the break in order to proceed with the analysis of the sample without breaking it.…”

“…Moayedi et al 2019. In the case of the Mont Terri Claystone, low shear stresses are recorded. Therefore it is a more significant challenge to detect breakpoints compared to high shear stresses of gneiss, migmatites (Renaud et al 2019), sandstone Basu 2018, Casagrande 2018), granite/diorite (Kim and Jeon 2019;Lee et al 2005;Singh and Basu 2016), limestone (Cai et al 2018;Morad et al 2019;Renaud et al 2019), quartzite (Singh and Basu 2018) or even to mortar (Ghazvinian et al 2012). This is linked to the fact that the shear surfaces of claystones are much smoother, therefore it is more difficult to observe surface changes related to shearing.…”

“…Previous analyses mainly dealt with the analysis of rock-rock (Grasseli and Egger 2003;Casagrande et al 2018;Kim and Jeon 2019;Morad et al 2019) and concrete-rock interfaces (Ghazvinian et al 2012;Renaud et al 2019). Approaches focusing on analyzing surface roughness (Muralha et al 2014;Özvan et al 2014), using photogrammetry (Casagrande et al 2018;Kim and Jeon 2019;Morad et al 2019) and statistical analyses of surfaces (Cai et al 2018;Renaud et al 2019) are also common. It is a fact that samples of different origin characterized by the same joint roughness coefficient can produce very different strengths.…”

“…The application of statistical tools to better understand shear strength measurement results has not yet to become common, despite the increasing number of studies dealing with the topic (Casagrande et al 2018;Morad et al 2019;Renaud et al 2019). In general practice, the break points (peak and residual strength) of shear strength-shear displacement curves are evaluated manually in a time consuming and quite subjective way which has numerous limitations (Muralha et al 2014).…”

Research of waterproofing screens of increased efficiency for preservation of objects of cultural heritage

“…Scientists have been studying the physical and mechanical properties of shell rock [1][2][3]. Many works are devoted to the protection of structures of the underground part of buildings and the device of waterproofing [4][5][6].…”