摘要
岩石中各种类型裂隙的相互影响是致使其变形破碎的重要原因,基于经典Kachanov法,通过分析所得应力强度因子比变化趋势,分别研究了拉剪和压剪两种状态下平行偏置双裂纹间水平距离、垂直距离、裂纹长度以及裂纹倾角对其相互作用的影响规律,对含不等长平行偏置裂纹的类岩试件进行单轴压缩试验,通过预制裂纹的起裂扩展和起裂荷载变化规律对理论分析进行了对比验证。结果表明:裂纹间的相互影响包括强化、屏蔽和零效应三方面,且随水平距离、垂直距离、裂纹长度和倾角的不同而相互转化;距离裂纹尖端越近,屏蔽和强化作用变化越剧烈,K_Ⅰ,K_Ⅱ分别在裂纹倾角为60°和30°时变化较剧烈。
The interaction of cracks with different locations and sizes is a key factor leading to the damage of rock. Based on the Kachanov method, the interaction rules between two offset parallel cracks with different level intervals, vertical intervals, crack lengths and crack angles are investigated by analyzing the stress intensity factor ratios under tension-shear stress and compression-shear stress. The compression tests on rock-like specimens with two unequal offset parallel cracks are performed, and the theoretical analysis is proved through the researches on the crack initiation and initial stress variation rules. The results shows that the offset parallel cracks exist reinforcing effect, shielding effect and null effect, and the three effects transform mutually along with the variations of level intervals, vertical intervals, crack lengths and angles. The reinforcing effect and shielding effect become more and more severe with the decrease of distance to the crack tip, and K_Ⅰ changes greatly when the crack angle is 60°and K_Ⅱ changes greatly when the crack angle is 30°.
作者
朱帝杰
陈忠辉
席婧仪
杨登峰
ZHU Di-jie CHEN Zhong-hui XI Jing-yi YANG Deng-feng(School of Mechanics and Civil Engineering, China University of Mining ＆ Technology, Beijing 100083, China China Building Technique Group Company, Beijing 100013, China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2017年第2期235-243,共9页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51174208
U1361209)
国家重点基础研究发展计划("973"计划)项目(2013CB227903)
