摘要
利用FLAC模拟了含初始随机材料缺陷的岩样的破坏前兆、声发射及最终破坏模式。比密实岩石弱的缺陷在破坏之后经历理想塑性行为。密实岩石在破坏之后先是经历线性应变软化行为,然后是理想塑性行为。材料缺陷在岩样内部的初始分布决定了剪切带的花样。尽管应变软化行为刚发生时在岩样内部形成了剪切带网络,但是岩样的最终破坏条带仅通过一条或几条剪切带。最终破坏条带的倾角在每个岩样内部都基本保持不变。剪切带倾角的数值解是以Coulomb倾角为上限,以Arthur倾角为下限。在应力的峰值附近和应变软化阶段,含缺陷少的岩样的声发射活动更加集中。
The failure precursor,acoustic emission and final failure mode are modeled using FLAC for heterogeneous rock specimen with initially random material imperfections in uniaxial plane strain compression.Beyond the failure of the imperfection,which is weaker than the intact rock,it undergoes ideal plastic behavior,while intact rock exhibits linear strain-softening behavior and then ideal plastic behavior once failure occurs.Shear band patterns depend on the distribution of initially random imperfections within the specimen.Although multiple shear bands can be formed when strain-softening behavior just occurs,the final shear fractures intersect the specimen only through a few shear bands.The shear band inclination approximately approaches a constant in residual deformational stage,which falls into the range of Arthur solution（the lower bound） and Coulomb solution（the upper bound）.The specimen with fewer material imperfections exhibits more apparent acoustic emission in the vicinity of peak stress and in strain-softening stage.
出处
《地下空间与工程学报》
CSCD
2007年第6期1047-1050,1059,共5页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金资助项目(50309004)
关键词
随机缺陷
剪切带
前兆
倾角
random imperfection
shear band
precursor
inclination angle
