摘要
为研究孔洞尺寸对岩石力学特性的影响,采用相似材料模型试验法,对不同孔径类岩石试件进行室内单轴压缩试验,初步分析孔径对岩石强度变形和破坏模式的影响.通过PFC 3D进行对应不同孔径模型试件的单轴压缩数值模拟,从细观角度与室内试验对比分析.研究发现PFC 3D模拟获得的不同孔径类岩石试件无论是应力-应变曲线,还是强度和变形模量的变化规律都与室内试验相似.在单轴压缩的作用下,孔径对岩石的强度和弹性模量均有衰减作用.含孔洞试件从开始压缩到彻底破坏的整个过程中都伴随着张拉型微裂纹的发展,初始裂纹均产生于孔洞边缘,当孔径较小时,初始微裂纹并未发生明显的扩展,但是当孔径较大时初始裂纹会继续向试件上下边界扩展,同时孔洞两侧剪切型微裂纹大量增加,最终由于拉剪混合作用导致破坏.
In order to study the influence of the hole size on the mechanical properties of the rock,the indoor uniaxial compression test was carried out on the rock specimens with different pore sizes by the similar material model test method,and the influence of the hole diameter on the rock strength deformation and failure mode was preliminarily analyzed.The uniaxial compression numerical simulation of the different aperture model specimens was carried out by PFC 3D,and was compared with the laboratory tests from the mesoscopic point of view.It was found that the stress-strain curves,strength and deformation modulus of rock samples with different hole sizes simulated by PFC 3D were similar to those of laboratory tests.Under the action of uniaxial compression,the hole sizes attenuate the strength and elastic modulus of rock.The development of tension-type microcracks is accompanied by the development of the hole-containing specimen from the beginning of compression to complete destruction,and the initial cracks all appear at the edge of the cavity.However,when the hole size is small,the initial microcracks do not significantly expand;when the hole size is large,the initial cracks will continue to develop towards the upper and lower boundaries of the specimen,and the number of shear microcracks on both sides of the hole will increase greatly,which will ultimately lead to failure due to the mixed action of tension and shear.
作者
崔嘉慧
梁奇锋
CUI Jiahui;LIANG Qifeng(School of Civil Engineering,Shaoxing University,Shaoxing,Zhejiang 312000)
出处
《绍兴文理学院学报》
2019年第9期38-45,共8页
Journal of Shaoxing University
关键词
孔洞尺寸
单轴压缩
力学性质
数值模拟
hole diameter
uniaxial compression
mechanical property
numerical simulation
