文献类型：期刊文献

中文题名：花岗岩巴西劈裂渐进破坏特征与能量演化研究

英文题名：PROGRESSIVE FAILURE CHARACTERISTICS AND ENERGY EVOLUTION OF GRANITE IN BRAZILIAN DISC TESTS

作者：沙鹏[1,2];杨丹莲[1];邬一鑫[1];伍法权[1,2]

机构：[1]绍兴文理学院土木工程学院,绍兴312000;[2]浙江省岩石力学与地质灾害重点实验室,绍兴312000

年份：2021

卷号：29

期号：5

起止页码：1258

中文期刊名：工程地质学报

外文期刊名：Journal of Engineering Geology

收录：CSTPCD、、CSCD2021_2022、北大核心、CSCD、北大核心2020

基金：国家自然科学基金(资助号:41831290,42007254)。

语种：中文

中文关键词：巴西劈裂;PFC^(2D);声发射;裂纹扩展;能量特征;

外文关键词：Braziliandisc test;PFC^(2D);Acoustic emission;Crack propagation;Energycharacteristics;

中文摘要：既有的巴西劈裂试验与模拟研究多集中在宏观破坏模式与细观演化规律上,对劈裂渐进过程的能量演化特征的分析较少。结合数字图像相关技术(DIC)与声发射实时监测,开展花岗岩的巴西劈裂实验。首先分析实验过程中,岩石破裂模式与破裂尺度的演化规律。在此基础上,采用颗粒流程序(PFC2D)对劈裂试验过程进行数值模拟,分析实验过程中内部裂纹演化过程的能量特征。试验与数值模拟对比结果表明:加载过程中岩样的损伤变化一共经历了4个阶段,即裂隙压密阶段(Ⅰ)、裂纹萌生阶段(Ⅱ)、裂纹扩展阶段(Ⅲ)、峰后破坏阶段(Ⅳ)。试样在裂隙萌生和裂纹扩展阶段以拉张型微破裂为主,裂纹扩展阶段后期产生剪切型破裂,并在加载直径方向形成大尺度裂纹并贯穿整个圆盘形成宏观破坏;试样在裂隙压密和萌生阶段几乎无耗散能,外力所做功几乎都转为岩体内可释放应变能,在破裂扩展后期应变能快速释放,声发射能量在峰值应力附近时达到最大值,峰后破坏阶段试件的可释放应变能快速减小,能量通过形成大量新裂面被耗散掉。

外文摘要：Previous research of Brazilian disc test and simulation is mostly focused on either macroscopic failure modes or micro evolution rules.The energy evolution characteristics in the splitting process remains to be discussed in detail.In this paper,Brazilian disc tests are carried out on granite.The fracture processes of specimens are monitored using digital image correlation(DIC)and acoustic emission(AE).Both fracture modes and scales during the test are analyzed.On this basis,PFC2D is employed to simulate the process of Brazilian disc test.The energy characteristics of specimen is illustrated by comparing different energy components.The test and simulation results indicate that:(1)The process of Brazilian disc test is divided into four stages,including fracture compaction(Ⅰ),cracks initiation(Ⅱ),cracks growth(Ⅲ)and post-peaking failure(Ⅳ)stage.(2)Tensile microcrack is the major fracture mode in both stageⅡandⅢ.Shear microcrack occurs at later period of stageⅢ.Then macrocrack forms in the loading diameter direction,and causes the final failure.(3)There is nearly no dissipated energy in first two stages.All the external work is transformed into releasable strain energy in the specimen.At the end of stageⅢ,the strain energy releases rapidly,and the energy of AE reaches to the maximum as the stress approaches to the peak.The releasable strain energy decreases remarkably at stage IV.The portion of dissipated energy increases significantly due to a large number of new fracture surfaces are formed.