中低围压花岗岩细观破坏机制的数值模拟  

Numerical Simulation on Granite Failure Mechanism at Meso-Level Under Moderate or Low Confining Pressure

作　　者：于庆磊[1] 杨天鸿[1] 刘洪磊[1] 唐春安[2] 

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110004 [2]大连理工大学土木水利学院,辽宁大连116024

出　　处：《东北大学学报（自然科学版）》2009年第7期1026-1029,共4页Journal of Northeastern University(Natural Science)

基　　金：国家重点基础研究发展规划项目(2007CB209405);国家自然科学基金资助项目(506740255087402410872046);教育部重点科技项目(107033);教育部高等学校博士学科点专项科研基金资助项目(200801450003)

摘　　要：采用数字图像处理技术表征花岗岩的细观结构,利用基于数字图像的岩石破裂过程分析系统(RFPA-DIP)建立反映花岗岩内部矿物颗粒分布的数值模型,进行花岗岩压缩数值试验,分析花岗岩压缩荷载作用下破坏机理.研究结果表明,花岗岩非均匀的细观结构起着使试件内部产生了拉应力区的作用;单轴压缩荷载作用下,试件在细观层次上以拉伸破坏为主;中低围压条件下,试件表现为张拉破坏和剪切破坏相互耦合的破坏方式,而且破坏机制随围压的增大是不断变化的,剪切破坏逐渐成为主控破坏方式.Digital image processing technologies were applied to characterizing the heterogeneity of granite so as to incorporate it into rock failure process analysis code based on digital image processing, i. e., RFPA-DIP, and a numerical model of granite was thus developed. The compression tests were carried out numerically to investigate granite failure mechanism at meso- level. The results show that the heterogeneity of rock results in the appearance of tensile stress zones. Under the condition of uniaxial compressive stress, the failure mechanism of granite at meso-level is mainly tensile failure, but under moderate or low confining pressures it is in tensileshear coupled failure modes. The failure mechanism changes with increasing confining pressure, and shear failure mode gradually comes to mainly controlled mode.

关 键 词：数字图像 非均匀性 张拉破坏 剪切破坏 拉应力区 

分 类 号：TU45[建筑科学—岩土工程] O241[建筑科学—土工工程]