Study on Mechanical Properties of Sandstone Based on Voronoi Block Model

doi:10.12068/j.issn.1005-3026.2021.11.012

Abstract

Abstract: The spherical particle and parallel bond model(PBM)in PFC(particle flow code) software is widely used to simulate the mechanical properties of rock. However， spherical particles and PBM have two intrinsic drawbacks: the grain shape of spherical particles is quite different from that of rock materials， and the ratio of unconfined compressive strength to tensile strength(UCS/TS)is low. Based on this， taking the typical sandstone in Lüliang area of Shanxi Province as an example， the rigid block numerical specimens are established by Voronoi tessellations， and the mechanical properties of sandstone are studied by using the softe-bond model(SBM). The results show that the scheme has three advantages compared with the traditional numerical simulation based on spherical particles and PBM: compared with the spherical sample， the grain interlocking between the rigid blocks increases， and the coordination number between the rigid block models increases significantly， which can better simulate the grain shape and mechanical behavior of real sandstone. The SBM can simulate the larger unconfined compressive strength to tensile strength ratio of sandstone， which can truly characterize the mechanical properties of sandstone under multiple stress paths. The numerical model based on rigid block and SBM can truly reflect the typical shear failure mode of sandstone.

Key words: sandstone; rigid block; Voronoi tessellations; soft-bond model; UCS/TS ratio

CLC Number:

TU45

SUN Hao ， CHEN Shuai-jun ， JIN Ai-bing ， LI Hai. Study on Mechanical Properties of Sandstone Based on Voronoi Block Model[J]. Journal of Northeastern University(Natural Science), 2021, 42(11): 1600-1608.

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