岩石三维内置裂隙的尺寸效应研究

发布时间：2018-04-03 21:38

本文选题：内置裂隙　切入点：裂隙尺寸效应　出处：《武汉理工大学学报》2015年08期

【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。
[Abstract]:By means of cutting and bonding technique and using red sandstone, the cylindrical specimen with three dimensional inner fissure is made. Through the experiment and CT image scanning analysis after crack expansion, the numerical simulation of crack propagation is combined.The influence of crack size on crack propagation, fracture failure and stress distribution in rock under uniaxial compression is studied.The results show that the reduction of peak strength and strain increases with the increase of crack diameter and opening degree, and with the increase of crack diameter, the reverse wing crack gradually exits from the fracture propagation process.The crack propagation mode is mainly wing crack, the propagation of wing crack and anti-wing crack is more intense with the increase of crack opening, the local fracture zone will appear when the specimen reaches the peak strength, and the boundary of the specimen has a certain influence on the stress distribution around the crack.With the increase of fracture diameter, the degree of decrease of tensile stress from stress concentration zone to specimen boundary decreases, the influence range of stress concentration gradually extends beyond the specimen boundary, and with the increase of crack opening degree,The decrease of tensile stress from the stress concentration zone to the specimen boundary is constant, and the influence range of stress concentration increases, but does not exceed the specimen boundary.
【作者单位】：山东科技大学山东省土木工程防灾减灾重点实验室;济南城建集团有限公司;
【基金】：国家自然科学基金(51279096,51409154) 山东省自然科学基金(ZR2012EEM030)
【分类号】：TU45

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