大理岩力学变形特性及非线性强度准则研究

Study on Mechanical Characteristics and Nonlinear Strength Criterion of Marble

以锦屏二级水电站为例,通过MTS815岩石与混凝土高温高压及破坏力学试验系统对引水隧洞大理岩做了不同围压下的三轴压缩试验,利用最小二乘法对Hoek-Brown和幂函数型Mohr岩石经验强度准则进行回归分析和比较。试验结果表明:高围压力作用下的深部岩体强度特性呈现明显的非线性特性,Hoek-Brown强度准则对三轴试验数据拟合程度较高,并能反映岩体质量对强度的影响,描述深部岩体的力学行为更具指导性。

Taking Jinping Ⅱ hydropower station for an example, triaxial compressive tests of marble diversion tunnel under conditions of confining pressure are carried out by using MTSS15 rock and concrete with high-temperature and high- pressure and failure mechanical test system. The least square method is used to fit the Hock-Brown and power-function Mohr nonlinear strength criterion. The test results show that the strength property of deep rock is nonlinear under the ac tion of high confining pressure; the fitting degree of Hock-Brown strength criterion is high, which reflects the influence of rock mass quality on its strength and has more guided meaning to describe the mechanics of deep rock mass.