Crack coalescence and strain accommodation in gypsum rock

Abstract

The micro-mechanisms involved in the deformation of gypsum rock have for long time interested the scientific world and are still not completely understood. The present work proposes an experimental investigation of strain accommodation in gypsum rock, reporting data referred to uniaxial and triaxial stress conditions. The rock deformation was investigated with a multiscale approach, with the comparison of results from DIC and microstructural analyses, aiming to propose an interpretation of crack coalescence and strain accommodation in natural gypsum rock (i.e. branching selenite facies), focusing on the influence of textural and compositional layering on the mechanical response. The failure was observed to coalesce following an unstable step-wise process. With the increase of confining pressure, the material develops a structure of plastic accommodation of strain, favoured by the peculiar crystallographic structure of gypsum, with water molecules layered in the salt structure.

Effect of Microstructure and Relative Humidity on Strength and Creep of Gypsum

“…According to Brace and Byerlee (1966) and Brantut et al (2011), these stress drops can be considered as a release of small fractions of the stress supported by the sample in consequence of the development of a microcrack or a small rock-bridge failure, in analogy with the seismic slip at the scale of natural earthquakes. This behaviour testifies an instable step-wise crack coalescence process, as suggested by the analysis proposed in Caselle et al (2020). This kind of evidences are not observable, however, in B-type samples that present uniform and regular post-peak curves.…”

Gestión ambiental de una empresa minera de yeso en Manaure, Colombia

“…Sus propiedades mecánicas son relevantes en una amplia gama de aplicaciones técnicas (por ejemplo, excavación de túneles, evaluación de la estabilidad de canteras subterráneas, acumulación de petróleo y gas). Los micromecanismos involucrados en la deformación de la roca de yeso han interesado durante mucho tiempo al mundo científico y aún no se comprenden completamente y requiere una atención específica a la evaluación de la gestión ambiental en este tipo de minería (Caselle et al, 2020). De este modo, la presente investigación estudia la gestión ambiental en empresas mineras que producen yeso.…”