摘要
利用MTS816岩石伺服系统对张开和充填四裂隙脆性砂岩进行单轴压缩试验,研究了应力应变曲线、峰值强度、破裂过程及最终破裂模式随倾角β1及充填状态的变化规律.应力应变曲线会随倾角β1的改变发生较大的变化,与完整试样相比存在较多的应力波动,而充填石膏一定程度上减少应力跌落.峰值强度随倾角β1的增大呈现先增大后减小的趋势,充填石膏会在一定程度上增加试样的峰值强度,但不会改变其随岩桥倾角的变化趋势.破裂过程中由于充填石膏限制了弹性应变能的释放,导致充填试样破坏前的裂纹萌生扩展较少,峰后破裂较突然.将中间裂隙的贯通模式分为2类,中间与外端裂隙的贯通模式分为5类,说明中间裂隙的贯通模式一定程度上受到外端裂隙的分布状态的影响,试样的贯通模式受到裂隙的空间分布影响较大而充填石膏对其影响较小.
The uniaxial compression experiment on the sandstone containing four pre-existing fissures,was carried out by MTS816 rock mechanics servo-controlled testing system,to investigate the effect of angle β1 and filling gypsum on stress-strain curves,peak strength,coalescence process and ultimate failure mode. The stress-strain curves of flawed specimen vary obviously with angle β1,and have more stress drops compare with intact sandstone specimen,whereas the filling gypsum would reduce stress drop to some extent. The peak strength first drops and then rises with the increasing of angle β1. The filling gypsum enhances the peak strength of the flawed specimens,but not affect the trend of peak strength. The filling gypsum restrict the releasing of the elastic strain energy,and lead to the crack initiation decreases before peak strength. The coalescence between two middle fissures can be classified into two models,and coalescence between middle and edge fissures can be classified into five models. The results indicate that the coalescence between middle fissures would change with angle β1 and the filling gypsum have little effect on coalescence model.
作者
田文岭
杨圣奇
殷鹏飞
TIAN WenlingI;YANG Shengqi;YIN Pengfei(State Key Laboratory for Geomeehanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China)
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2018年第5期1005-1015,共11页
Journal of Basic Science and Engineering
基金
江苏省杰出青年基金项目(BK20150005)
江苏省第五期“333工程”科研资助项目
江苏省研究生科研与实践创新计划项目(KYCX18_1969)
关键词
预制裂隙
岩桥倾角
破裂过程
破裂模式
pre-existing fissure
ligament angle
crack coalescence process
ultimate failure mode
