论文部分内容阅读
对灰岩试样进行加轴压、卸围压破坏试验,研究了不同卸围压速度下灰岩的变形特征和力学参数变化,取得了一些新的结论:卸荷岩样的破坏是沿卸荷方向的强烈扩容所致;随着卸荷速度的增加,岩样的破坏特征从主剪切破坏、共轭剪切破坏逐渐变为劈裂加剪切破坏;在相同的卸荷初始围压下,卸围压速度越快,岩样破坏的应力差越小;在相同的卸荷速度下,随着卸荷初始围压的增加,岩样破坏的应力差逐渐增加;在相同的卸荷速度下,卸荷初始围压越大,轴向应变的回弹值愈大,环向应变突跳值愈小;随着卸荷速度的增加,岩样黏聚力c逐渐增加,内摩擦角Φ逐渐减小。
The limestone samples were subjected to axial compression and unloading confining pressure failure tests. The deformation characteristics and mechanical parameters of limestone under different unloading rates were studied. Some new conclusions were obtained: As the unloading speed increases, the failure characteristics of the rock specimen gradually change from the main shear failure and the conjugate shear failure to the splitting and shear failure. At the same initial unloading confining pressure Under the same unloading speed, with the increase of unloading initial confining pressure, the stress difference of rock failure gradually increases. Under the same unloading rate, The higher the unloading initial confining pressure is, the larger the rebound value of axial strain is and the smaller the value of annular strain kicking is. With the increase of unloading velocity, the cohesion c of rock specimen increases gradually and the internal friction angle Φ decreases gradually.