应变速率对红砂岩预制隙裂贯通破坏的影响

为了探究应变速率对节理岩体裂纹扩展形态和贯通破坏的影响,提出在室内制作含裂隙的红砂岩试样,采用不同加载速率进行单轴加载试验,观察裂隙起裂、贯通、破坏的全过程,并在物理试验基础上利用数值分析软件对结果进行分析和验证。结果表明:随着加载速率的增加,试样的峰值强度增加,试样发生应力强度跌落时的应变也有一定的增长;裂隙的扩展方式不局限于沿着试件高度方向开展,有部分裂隙发生横向方向的扩展和贯通,导致试样逐渐从局部破坏形式向整体破坏形式发展;裂隙强度在单轴加载时伴随裂隙倾角和加载速率的增加而变大,裂隙贯通强度对裂隙倾角的变化更敏感。

Effect of strain rates on failure of red sandstone containing two pre-existing fissures under

To figure out the effect of strain rates on crack growth and the failure of joint rocks, uniaxial loading tests were carried out on red sandstone specimens containing two pre-existing flaws under different uni-axial strain rates, and the whole process of crack growth was observed. Based on the physical test,the numerical simulation was proposed to analyze and verify the result. It is shown that the peak strength increases with strain rate, and the corresponding strain increases when the stress drops as well. In addition, as the strain rates increase, cracks spread to both H direction and L direction, resulting in the specimens change from local failure to general demolition. Furthermore, the fissure strength increases with fissure angle and loading speed, but the failure strength is more sensitive to fissure angle.