辉绿岩单轴及常规三轴压缩下力学特性试验研究

为了分析坚硬脆性岩石在单轴及常规三轴压缩条件下的强度和变形特性,通过在TAW-2000微机控制电液伺服试验机上对辉绿岩进行单轴及常规三轴压缩试验,主要分析辉绿岩在围压为1、3、5、10 MPa时基本物理力学参数的离散程度,其弹性模量的离散程度指标值较小,在0.27%～3.49%波动,能较好地表征辉绿岩的变形特性。试验结果表明:随着围压的增大,岩石峰值应变和残余应变均表现出显著的线性增长关系,可采用一次函数形式拟合,弹性模量、变形模量和泊松比均表现出较明显的非线性增长关系,可采用幂函数形式进行拟合,但并不会随着围压的增大而无限增大,而是趋于一个稳定值,这一规律为实际工程中不同地应力条件下准确选取弹性模量、泊松比等参数提供理论基础;随着围压的增大,岩石的峰值强度和残余强度均呈现出较显著的线性增长关系,可采用一次函数形式拟合,并计算出黏聚力和内摩擦角,为岩石工程设计时强度参数的选择提供参考依据。

Experimental Research on Mechanical Properties of Diabase under Uniaxial and Conventional Triaxial Compression

In order to analyze the strength and deformation characteristics of hard and brittle rock under uniaxial and conventional triaxial compression conditions, experiments were carried out to research the diabase under uniaxial and conventional triaxial compression by the TAW-2000 microcomputer controlled electro-hydraulic servo test machine. It mainly analyzes the degree of dispersion of basic physical and mechanical parameters of the diabase when the confining pressure is 1, 3, 5, 10 MPa. The dispersion index of elastic modulus is better, fluctuating between 0.27% and 3.49%, which primely represents deformation characteristics of the diabase. The experimental results show that with the increase of confining pressure, the peak strain and residual strain of rock show a significant linear growth relationship, which can be fitted by one-time function. The elastic modulus, deformation modulus and poisson"s ratio all show obvious nonlinear growth relationship. The power function can be used to fit, but it does not increase indefinitely with the increase of confining pressure, but tends to a stable value. This distinction provides a theoretical basis for accurately selecting parameters such as elastic modulus and poisson"s ratio under different ground stress conditions in practical engineering. With the confining pressure increases, the peak strength and residual strength of the rock show a significant linear growth relationship. The function can be fitted in a one-time function, and the cohesion and internal friction angles can be calculated, which provides a reference for rock mechanics design selection of strength parameters.