各向异性片麻岩点荷载与单轴压缩力学特性研究

Study on the Mechanical Characteristics of Anisotropic Gneiss under Point Load and Uniaxial Compression

以水电站的片麻岩为研究对象,对垂直和平行层理的岩样分别进行了点荷载试验和单轴压缩试验,分析片麻岩在这两种试验下的各向异性力学特性,并研究其点荷载强度与单轴抗压强度之间的相关性。研究结果表明:在点荷载和单轴压缩试验中,片麻岩的各向异性力学特征表现得十分明显,垂直层理的强度明显大于平行层理的强度。其破坏模式在两种层理角度下也存在显著的差异,并且片麻岩点荷载强度指数I_(s(50))与单轴抗压强度R_(c)之间的修正指数m和换算系数也有明显的不同。片麻岩在垂直层理下的修正指数m=0.44,换算系数为29.78,平行层理下m=0.42,换算系数为33.04。

In this paper,the point load test and uniaxial compression test were carried out on the vertical and parallel stratification of gneiss samples from hydropower station respectively. Through the experiment the author analyzed the anisotropic mechanical properties of gneiss,and studied the correlation between the point load strength and the uniaxial compressive strength. The results show that in uniaxial compression and point load experiments,the anisotropic mechanical characteristics of gneiss are very obvious, and the strength of vertical stratification is obviously greater than that of parallel stratification. The failure modes under different stratifications are also significantly different. The correction index m and the conversion coefficient between the point load strength index I_(s(50))and the uniaxial compressive strength R_(c) of gneiss are also obviously different. The correction index of gneiss m is 0.44 under vertical stratification and m = 0.42 under parallel stratification. The conversion coefficient between Is(50)and Rcof gneiss is 29.78 under vertical stratification and 33.04 under parallel stratification.