岩石单轴声发射及能量耗散特征颗粒流模拟研究  

Particle Flow Study on Uniaxial Acoustic Emission and Energy Dissipation Characteristics of Rock

作　　者：杨江坤 宋彦琦 马宏发[2] 郑俊杰 杨俊涛 鲍伟 YANG Jiangkun;SONG Yanqi;MA Hongfa;ZHENG Junjie;YANG Juntao;BAO Wei(State Key Laboratory of Coal Resources and Safe Mining,China University of Mining&Technology(Beijing),Beijing 100083,China;School of Mechanics&Civil Engineering,China University of Mining and Technology,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京100083 [2]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《矿业研究与开发》2023年第4期88-94,共7页Mining Research and Development

基　　金：中国矿业大学(北京)煤炭资源与安全开采国家重点实验室开放基金项目(SKLCRSM20KFA1)。

摘　　要：基于石膏岩室内单轴声发射试验,结合PFC^(2D)颗粒流模拟,分析了单轴压缩下岩石声发射演化特征,从空间角度反演了微裂纹萌生、汇集到破坏的过程,同时对渐进破坏过程的能量变化进行分析。研究结果表明:岩石颗粒流细观参数对宏观参数的显著性影响各不相同,利用正交试验及回归分析可量化宏细观参数关系;单轴压缩过程中,声发射事件在峰后阶段大量产生,发展过程可依次划分为无损期、平静期、增长期和陡增期,声发射事件陡增期存在沉寂期,可作为岩石破坏的前兆判据;岩石模型内部最先出现张拉裂纹,峰前阶段内部裂纹随机产生,汇集性并不明显,宏观破裂面形成于峰后阶段,且破裂面附近富集大量拉伸裂纹;岩石内部能量在峰前阶段以弹性能储存为主,峰后应变能大量释放,耗散能急剧增加,能量耗散比呈“N”形变化;基于声发射试验结果所得本构模型更适用于描述离散元单轴压缩过程中的应力应变关系。Based on indoor uniaxial acoustic emission tests of gypsum rocks and PFC^(2D) particle flow simulation,the acoustic emission evolution characteristics of rocks under uniaxial compression were analyzed.The process of microcrack initiation,convergence and failure was inverted from a spatial perspective,and the energy variation in the progressive failure process was analyzed.The results are concluded as follows.Firstly,the mesoscopic parameters of rock particle flow have different influences on the significance of macroscopic parameters,and the relationship of macro-mesoscopic parameters can be quantified by orthogonal tests and regression analysis.Secondly,in the process of uniaxial compression,a large number of AE events occur in the post-peak stage,and the development process can be successively divided into non-destructive period,quiet period,growth period and sharp increase period.Before the sharp increase of AE events,there is a local quiet period,which can be used as a precursor criterion of rock failure.Thirdly,tensile cracks appear first inside of the rock model,and internal cracks occur randomly in the pre-peak stage,without obvious convergence.The macroscopic fracture surface is formed in the post-peak stage,and a large number of tensile cracks are concentrated near the fracture surface.Fourthly,in the pre-peak stage,the internal energy of rock is mainly stored as elastic energy,and the post-peak strain energy is released in large quantities,and the dissipative energy increases sharply.The energy dissipation ratio shows a"N"type change.The constitutive model based on acoustic emission test results is more suitable to describe the stress-strain relationship in discrete element uniaxial compression.

关 键 词：单轴压缩 声发射 颗粒流模拟 能量耗散 石膏岩 

分 类 号：TD315[矿业工程—矿井建设] TU45[建筑科学—岩土工程]