含不同倾角单裂隙岩石单轴压缩破裂演化过程分析  

Analysis of fracture evolution process of single fractured rock mass based on uniaxial compression

作　　者：赵娜[1] 卫帅 王来贵[1] 孟利新 ZHAO Na;WEI Shuai;WANG Laigui;MENG Lixin(College of Mechanics and Engineering,Liaoning Technical University,Fuxin 123000,Liaoning,China)

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁阜新123000

出　　处：《实验力学》2024年第4期518-528,共11页Journal of Experimental Mechanics

基　　金：国家重点研发计划(2017YFC1503101);辽宁省重点科技创新基地联合开放基金项目(2020-KF-13-06);辽宁省教育厅基础研究项目(LJ2020JCL013)。

摘　　要：为探究裂隙倾角对裂隙岩体破裂演化过程的影响,本文对不同裂隙倾角岩体进行单轴压缩试验,采用数字散斑和声发射方法作为观测手段,探究含不同裂隙倾角岩体的破裂演化过程,分析了不同单裂隙岩体表面及其内部裂纹的演化规律。结果表明:裂隙岩体的变形破坏过程与完整岩体相似,表现为原始裂隙压密、弹性变形、塑性变形及破坏4个阶段;随着裂隙倾角的增大,应力的峰值即抗压强度呈现先减小后增大的趋势。当岩体表面裂纹处于稳定扩展阶段时,裂纹首先沿着预制裂隙端部起裂,然后裂纹扩展、贯通,形成宏观裂纹,直至宏观裂纹发展至非稳定扩展阶段;当裂隙倾角为0°时,岩体表现出较明显的张拉破坏,当裂隙倾角为30°、45°和60°时,岩石呈现出以剪切为主的组合破坏,当裂隙倾角为90°时,岩体发生张拉破坏。通过声发射观测结果,观测了单裂隙岩体内部裂纹的演化过程,在声发射初始期,岩体内部存在大量孔隙,随着应力的增加,原生孔隙逐渐被压密,所收集到的振铃计数较少;随着变形的增加,岩体进入弹性变形阶段,岩石内部产生微裂纹,振铃计数与初始期相比变多且趋于稳定状态;当进入塑性变形阶段即裂纹稳定扩展阶段,裂纹在岩体表面沿预制裂隙起裂并不断发育,直到裂纹贯通,岩体形成宏观破裂到达破坏阶段。随着裂隙倾角的改变,内部裂纹扩展情况产生差异,导致单裂隙岩体塑性变形阶段来临时间呈现先减小后增加的趋势。In order to investigate the influences of fissure inclination on the rupture evolution process of fissured rock body,this paper carried out uniaxial compression experiments on rock bodies with different fissure inclinations.The digital scattering and acoustic emission methods were adopted as the observation means to investigate the rupture evolution process of rock bodies containing different fissure inclinations.And the evolution law of the surface of the different single-fissure rock bodies and their internal cracks were analyzed as well.The results show that the deformation and destruction process of the fractured rock body is similar to that of the intact rock body,which is manifested in four stages:original fracture compaction,elastic deformation,plastic deformation and destruction;with the increase of fracture inclination,the peak stress,i.e.,the compressive strength,shows a tendency of decreasing first and then increasing.When the cracks on the surface of the rock body are in the stable expansion stage,the cracks firstly start cracking along the end of the prefabricated cracks,and then the cracks expand,penetrate,and form macroscopic cracks until the macroscopic cracks develop to the unstable expansion stage.When the inclination angle of the cracks is 0°,the rock body shows a more obvious tensile damage.The rocks show a combination of shear-dominated damage when the inclination angles of the cracks are 30°,45°,and 60°The rock body shows a combination of shear-dominated damage when the inclination angle of the cracks is 90°,and the rock body undergoes elastic deformation.When the fissure inclination angle is 90°,the rock body undergoes tensile damage.Through the acoustic emission observation,the evolution of cracks inside the single-fracture rock body is observed.In the initial period of acoustic emission,there are a large number of pores inside the rock body.With the increase of stress,the primary pores are gradually compressed and dense,and the collected ringer counts are relatively small.With the i

关 键 词：单裂隙 裂纹演化 数字散斑 声发射 单轴压缩 

分 类 号：TU45[建筑科学—岩土工程]