摘要
岩体在开挖工程中卸荷,岩石轴向应力增加径向应力减小,可采用升轴压卸围压三轴试验模拟开挖过程。使用电液压伺服可控制刚性试验机,对取自某水电站的标准岩样进行常规三轴和升轴压卸围压三轴试验,根据两种试验方法下获得的应力、应变等试验数据分析得出了如下结论:(1)大理岩变形模量损伤因子M和初始围压σ3、泊松比损伤因子N和初始围压σ3均呈二次非线性关系。(2)侧向变形速度明显加快,宏观上表现出扩容,有较强的张性破坏特征,在围压相等的条件下卸荷,张性裂隙沿着两个方向发展,直至破坏。
The axial stress of marble increases and its radial stress decreases in rock mass excavation, so the triaxial test of lifting shaft pressure and unloading confining pressure is used for simulating the excavation process. For the standard samples of the diversion tunnel from a hydropower station, the controlled stiffness test machine with electric-hydraulic ser- vo is used to do the conventional triaxial test and the triaxial test of lifting shaft pressure and unloading confining pres- sure. Based on the analyses for the stress, strain and other data from the two test methods, follows： （1） The rock deformation modulus damage factor M and initial confining pressure ratio damage the conclusions are drawn as σ3, as well as the Poisson＇s factor N and initial confining pressure σ3 are all the secondary nonlinear relationship. （2） The lateral defor- mation velocity is accelerated apparently, and the macroscopic phenomena appears expansion and strong tensile failure characteristics. When unloading with the same condition of confining pressure, the tensile crack develops along the two directions, until the destruction.
出处
《水利与建筑工程学报》
2013年第2期107-110,共4页
Journal of Water Resources and Architectural Engineering
基金
国家重点基础研究发展计划(973)资助项目(2011CB013504)
国家自然科学基金项目(41272329)
深部岩土力学与地下工程国家重点实验室资助项目(SKLGDUEK0902)
关键词
深埋隧洞
大理岩
卸荷破坏
力学特性
关系拟合
deep-buried tunnel
marble
unloading failure
rock mechanics characteristics
relation curve fitting
