中文摘要：

采用切割、粘结技术,利用红砂岩制作了含三维内置裂隙的圆柱体试件,通过试验和裂隙扩展后的CT图像扫描分析,结合裂隙扩展的数值模拟,研究了在单轴压缩条件下裂隙尺寸的变化对岩石裂隙扩展、破坏规律和应力分布的影响。结果表明,含裂隙试件的峰值强度和峰值应变的折减程度随裂隙直径和张开度的增大而增大;随裂隙直径的增大,反翼裂纹逐渐退出裂隙扩展过程,裂隙扩展方式以翼裂纹为主;翼裂纹与反翼裂纹的扩展随裂隙张开度的增大而越剧烈,试件到达峰值强度时会出现局部破碎区;试件边界对裂隙周围应力分布有一定影响,随裂隙直径的增大,拉应力从应力集中区至试件边界的递减程度减小,应力集中影响范围逐渐超出试件边界;随裂隙张开度的增大,拉应力从应力集中区至试件边界的递减程度不变,应力集中影响范围增大,但未超出试件边界。

英文摘要：

A cylinder test specimen with three-dimensional internal cracks was made by cutting and bonding techniques as well as red sandstone.Based on the test and CT image scanning analysis after the crack extension,and combined with the numerical simulation of crack extension,the impacts on crack extension,failure law and stress distribution of rocks from the changes of crack size under the condition of uniaxial compression were studied.The experimental results show that the reduction degree of peak intensity and peak strain of specimen with cracks increase with the increase of the diameter and width of cracks;as the crack＇s diameter increases,the anti-wing crack edges out of the extension process and the crack takes wing crack as main extension mode;the extension of wing cracks and anti-wing cracks becomes more violent with the increase of crack＇s width and local fracture zone will appear when the specimen reaches the peak intensity.The specimen boundary has certain influence on the distribution of stress around the cracks：as the diameter of the cracks increases,the reduction degree of tensile stress from the area of stress concentration to boundary becomes smaller and the range of influence of stress concentration gradually exceeds the boundary;as the width of cracks increases,the reduction degree of tensile stress from the area of stress concentration to boundary remains constant and the range of influence of stress concentration becomes larger but still stays within the boundary.