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论文类型：期刊论文

发表时间：2014-03-01

发表刊物：INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

收录刊物：SCIE、EI、Scopus

卷号：51

期号：5

页面范围：1132-1148

ISSN号：0020-7683

关键字：Numerical simulations; Macroscopic pre-existing flaws; Fracture evolution; Heterogeneous rock

摘要：Macroscopic pre-existing flaws play an important role in evaluating the strength and the failure modes of a heterogeneous rock mass. Crack initiation, propagation and coalescence from macroscopic pre-existing flaws are considered in a 3-D numerical model (RFPA3D) to investigate their effects on the underlying failure modes of rock. A feature of the code RFPA3D is that it can numerically simulate the evolution of cracks in three-dimensional space, as well as the heterogeneity of the rock mass. Three types of flaw geometries were evaluated numerically against experimental results: Type A for intact specimen, and Types B and C for flawed cylindrical specimens with different macroscopic pre-existing flaws, respectively. The effect of confining pressure on the fracture evolution was also considered. Numerical results showed that both the ligament angle and the flaw angle of two pre-existing cracks can affect the uniaxial compressive strength of the specimen and the mechanism of fracture evolution. In addition, both the uniaxial compressive strength and the accumulated acoustic emission increase with increasing heterogeneity. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.