The Influence of Grain Size Distribution on Mechanical Compaction and Compaction Localization in Porous Rocks

The modes of formation clastic rocks result in a wide variety microstructures, from poorly-sorted heterogeneous to well-sorted and nominally homogeneous rocks. mechanical behavior failure mode is known vary with microstructural attributes such as porosity grain size. However, the influence size distribution, particular degree polydispersivity or modality not yet fully understood, because it difficult study experimentally using natural To better understand distribution on porous rocks, we prepared suites synthetic samples consisting sintered glass beads polydisperse distributions. We performed hydrostatic compression experiments found that, all else being equal, onset crushing occurs much more progressively at lower pressure than monodisperse samples. conducted triaxial regime shear-enhanced compaction that stress required reach inelastic was compared Further, our observations show bands developed monomodal while delocalized cataclasis bimodal samples, where small grains were systematically crushed largest remained intact. In detail, increases, deformation features appear transition localized through hybrid stage front diffuse propagates both ends sample toward its center increasing bulk strain.