摘要
层理黄砂岩为隧道工程建设中常见的一种岩石,隧道开挖及后期运行导致围岩长期处于循环荷载作用下.为了探究层理黄砂岩循环加卸载损伤破裂特征,借助PFC^(2D)开展了不同围压不同倾角层理黄砂岩常规三轴循环加卸载研究,分析了应力-应变曲线及损伤破裂过程,得到1组可以反映层理黄砂岩常规三轴压缩力学特征的细观参数,数值试样强度及破裂特征与室内试验结果吻合较好.数值模拟循环加卸载应力-应变曲线可以一定程度上反映力学行为,同时循环加卸载曲线和单调加载曲线变化形态吻合较好.不同倾角层理砂岩循环荷载下试样破裂特征不同,当α=0°时试样发生贯穿基质的剪切破坏,循环荷载与单调加载破裂特征相似.而当α=60°时,层理发生剪切破坏,并伴随层理两侧基质的破坏,循环荷载相对于单调加载裂纹宽度有所增加.
Bedding yellow sandstone is a common rock in tunnel construction,and the surrounding rock is under cyclic loading-unloading for a long time due to tunnel excavation and later operation.To explore the damage and fracture characteristics of bedding yellow sandstone under cyclic loading-unloading compression,the triaxial cyclic loading-unloading compression of bedding yellow sandstone with different confining pressures and dip angles was constructed with the help of PFC^(2D).The stress-strain curve and fracture process were analyzed.A group of micro-parameters was obtained,which can simulate the mechanical behavior of bedding yellow sandstone under triaxial compression,and the strength and fracture characteristics obtained by numerical simulation is similar to that obtained by experiment.The stress-strain curves of specimens under cyclic loading-unloading compression can reflect the mechanical behavior of bedding yellow sandstone,and the stress-strain curve of specimens under cyclic loading-unloading compression are similar to that under monotonic loading.Fracture characteristics of sandstone samples with different dip angles are different under cyclic loading,the shear crack across the matrix whenα=0°,which is similar to that under monotonic loading.Whereas whenα=60°,the shear across the bedding and with the destruction in the matrix on the sides of the bedding.Under cyclic loading-unloading compression,the width of shear crack is more than that under monotonic loading.
作者
甄治国
杨圣奇
陈传平
田文岭
钱建华
李旭
ZHEN Zhiguo;YANG Shengqi;CHEN Chuanping;TIAN Wenling;QIAN Jianhua;LI Xu(China Railway 20th Bureau Group 4th Engineering Co.Ltd.,Qingdao 266061,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
2023年第3期731-740,共10页
Journal of Basic Science and Engineering
基金
中央高校基本科研业务费项目(2021ZDPYJQ002)
关键词
层理黄砂岩
三轴循环
变形特性
离散元模拟
细观机理
损伤演化
bedding yellow sandstone
triaxial cycling
deformational characteristics
discrete element modeling
meso-mechanism
damage evolution
作者简介
甄治国(1977—),男,学士,高级工程师,项目经理;通信作者:杨圣奇(1978—),男,博士后,教授,博士生导师.E-mail:yangsqi@hotmail.com
