柱状节理岩体各向异性强度准则研究

ANISOTROPIC STRENGTH CRITERION FOR COLUMNAR JOINTED ROCK MASSES

以正六棱柱型柱状节理岩体为研究对象,根据柱状节理的分布特性,在参考Ramamurthy非线性强度准则的基础上,引入节理系数表征节理对岩体强度的影响,建立正六棱柱型柱状节理岩体各向异性强度准则。该强度准则以幂指数形式反映柱状节理岩体的强度非线性。分析时首先针对正六棱柱型柱状节理岩体,研究节理系数的计算方法,然后结合模拟柱状节理岩体单轴和三轴压缩试验结果确定各向异性强度准则中的常数,在此基础上采用已有试验数据对该各向异性强度准则进行初步验证。结果表明:该各向异性强度准则能够较好地反映柱状节理岩体强度的各向异性和非线性,预测值与实测值比较吻合。

A joint factor reflecting the distribution characteristics of columnar joints was introduced to represent the influences of joints on the strength of columnar jointed rock masses based on the nonlinear strength criterion proposed by Ramamurthy. An anisotropic strength criterion was suggested for the regular hexagonal columnar jointed rock masses with the strength nonlinearity being described with the power function. The method for calculating the joint factors of regular hexagonal columnar jointed rock masses was investigated,and the constants in the anisotropic strength criterion were determined with the uniaxial and triaxial compression results from tests simulating the columnar jointed rock masses. The experimental results on the strength of jointed rock masses published in the past literatures were used to validate the proposed strength criterion preliminarily. From the validation,it was found that the predictions from the proposed strength criterion agreed well with the experimental data,indicating that the anisotropic strength criterion described well the strength anisotropy and nonlinearity of columnar jointed rock masses.