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D0I:10.13374/1.issm100103.2008.08.022 第30卷第8期 北京科技大学学报 Vol.30 No.8 2008年8月 Journal of University of Science and Technology Beijing Aug.2008 不同强度岩石的破坏过程及声发射数值模拟 王学滨 辽宁工程技术大学力学与工程科学系，阜新123000 摘要采用FLAC模拟了初始内聚力及内摩擦角对具有随机材料缺陷单轴平面应变压缩岩样破坏过程及声发射的影响： 采用编写的若干FI$H函数规定随机缺陷及统计发生破坏的单元数目·密实的岩石服从莫尔一库仑剪破坏与拉破坏复合的破 坏准侧，破坏之后呈现应变软化一理想塑性行为：缺陷在破坏之后经历理想塑性行为·随着密实岩石强度参数的提高，从应力 峰值到残余应力的应力降、轴向应变增量提高，贯通试样的剪切带出现滞后，试样内部最终发生破坏的单元数降低。对于密实 岩石强度参数高的试样，缺陷全部发生破坏之后，密实岩石没有立即发生破坏：应力峰值被达到之后，破坏的单元数增长不 大·在加载过程中，声发射数有显著增加的三个区段.区段1、2及区段3的绝大部分位于峰前：在区段3的峰前阶段，声发射 数的增加源于缺陷的长大、聚结、传播和竞争.强度参数越高，区段3越长，区段3的蜂值越低·这表明当密实岩石的强度参数 较高时，密实岩石单元破坏相继发生，破坏过程持续得较长 关键词岩石：破坏过程：内聚力：内摩擦角：剪切带：声发射：随机缺陷 分类号TU452 Numerical simulation of failure processes and acoustic emissions of rock specimens with different strengths WA NG Xuebin Department of Mechanics and Engineering Sciences.Liaoning Technical University,Fuxin 123000.China ABSTRACT For rock specimens with initially random material imperfections in uniaxial plane strain compression,the effects of ini- tial cohesion and internal friction angle on the failure processes were modeled using FLAC.FISH functions were used to generate ran- dom imperfections and to remember the number of failed elements.For the intact rock exhibiting the linear strain"softening behavior beyond the occurrence of failure and then the ideal plastic behavior,the failure criterion is a composite Mohr-Coulomb criterion with tension cut-off.The imperfection undergoes the ideal plastic behavior beyond the occurrence of failure.As the strength parameters (initial cohesion and internal friction angle)increase,the stress drop and incremental axial strain from the peak stress to the residual stress increase:the occurrence of shear fractures intersecting the specimen is later and the final number of yielded elements decreases. For the intact rock with higher strength parameters,after all imperfections fail it does not fail immediately:instead.when the axial stress reaches a certain value it starts to yield and the increase in the number of failed elements is less apparent beyond the peak stress. In the loading process.the acoustic emissions are apparent in three stages.The first stage,the second stage and a majority of the third stage appear at pre-peak.Prior to the peak stress and in the third stage,the increase in the acoustic emissions results from the extension,coalescence and propagation of imperfections and the competition among imperfections.Higher strength parameters of the intact rock cause the third stage to be wider and the number of acoustic emissions to be lower.suggesting that the failure is more pro- gressive and the failure duration is longer. KEY WORDS rock:failure process:cohesion:internal friction angle:shear band:acoustic emission:random imperfection 岩石的内聚力及内摩擦角越高，岩石的强度越 的是，在实验研究中，不能确保若干岩样仅有不同的 高，高内摩擦角将引起高的剪切带倾角]，遗憾 内聚力及内摩擦角，而有其他相同的物理、力学参 收稿日期：2007-07-29修回日期：2007-09-12 基金项目：国家自然科学基金资助项目(N0~50309004) 作者简介：王学滨(1975一)男，副教授，博士，E mail:wxbbb@263.nct不同强度岩石的破坏过程及声发射数值模拟 王学滨 辽宁工程技术大学力学与工程科学系阜新123000 摘 要 采用 FLAC 模拟了初始内聚力及内摩擦角对具有随机材料缺陷单轴平面应变压缩岩样破坏过程及声发射的影响； 采用编写的若干 FISH 函数规定随机缺陷及统计发生破坏的单元数目．密实的岩石服从莫尔－库仑剪破坏与拉破坏复合的破 坏准则破坏之后呈现应变软化－理想塑性行为；缺陷在破坏之后经历理想塑性行为．随着密实岩石强度参数的提高从应力 峰值到残余应力的应力降、轴向应变增量提高贯通试样的剪切带出现滞后试样内部最终发生破坏的单元数降低．对于密实 岩石强度参数高的试样缺陷全部发生破坏之后密实岩石没有立即发生破坏；应力峰值被达到之后破坏的单元数增长不 大．在加载过程中声发射数有显著增加的三个区段．区段1、2及区段3的绝大部分位于峰前．在区段3的峰前阶段声发射 数的增加源于缺陷的长大、聚结、传播和竞争．强度参数越高区段3越长区段3的峰值越低．这表明当密实岩石的强度参数 较高时密实岩石单元破坏相继发生破坏过程持续得较长． 关键词 岩石；破坏过程；内聚力；内摩擦角；剪切带；声发射；随机缺陷 分类号 TU452 Numerical simulation of failure processes and acoustic emissions of rock specimens with different strengths W A NG Xuebin Department of Mechanics and Engineering SciencesLiaoning Technical UniversityFuxin123000China ABSTRACT For rock specimens with initially random material imperfections in uniaxial plane strain compressionthe effects of initial cohesion and internal friction angle on the failure processes were modeled using FLAC．FISH functions were used to generate random imperfections and to remember the number of failed elements．For the intact rock exhibiting the linear strain-softening behavior beyond the occurrence of failure and then the ideal plastic behaviorthe failure criterion is a composite Mohr-Coulomb criterion with tension cut-off．T he imperfection undergoes the ideal plastic behavior beyond the occurrence of failure．As the strength parameters （initial cohesion and internal friction angle） increasethe stress drop and incremental axial strain from the peak stress to the residual stress increase；the occurrence of shear fractures intersecting the specimen is later and the final number of yielded elements decreases． For the intact rock with higher strength parametersafter all imperfections fail it does not fail immediately；insteadwhen the axial stress reaches a certain value it starts to yield and the increase in the number of failed elements is less apparent beyond the peak stress． In the loading processthe acoustic emissions are apparent in three stages．T he first stagethe second stage and a majority of the third stage appear at pre-peak．Prior to the peak stress and in the third stagethe increase in the acoustic emissions results from the extensioncoalescence and propagation of imperfections and the competition among imperfections．Higher strength parameters of the intact rock cause the third stage to be wider and the number of acoustic emissions to be lowersuggesting that the failure is more progressive and the failure duration is longer． KEY WORDS rock；failure process；cohesion；internal friction angle；shear band；acoustic emission；random imperfection 收稿日期：2007-07-29 修回日期：2007-09-12 基金项目：国家自然科学基金资助项目（No．50309004） 作者简介：王学滨（1975－）男副教授博士E-mail：wxbbb＠263．net 岩石的内聚力及内摩擦角越高岩石的强度越 高高内摩擦角将引起高的剪切带倾角［1－2］．遗憾 的是在实验研究中不能确保若干岩样仅有不同的 内聚力及内摩擦角而有其他相同的物理、力学参 第30卷 第8期 2008年 8月 北 京 科 技 大 学 学 报 Journal of University of Science and Technology Beijing Vol．30No．8 Aug．2008 DOI:10．13374／j．issn1001－053x．2008．08．022