单轴动静组合加载对岩石力学特性影响的试验研究

Test and Study of Mechanical Properties of Rock Under Uniaxial Static-and-dynamical Combination Load

用低周疲劳加载方法,在Instron电液伺服材料试验机上对红砂岩进行了单轴动静组合加载试验,研究了组合加载条件下的岩石动态响应和破坏特性。实验发现:红砂岩在同一方向上动静组合加载条件下的破坏强度比在单独动载作用条件下的强度小,而比在单独静载作用条件下的强度大。在组合加载条件下,岩石的弹性模量随着预静载的增加而减小,并显现出软化的趋势。实验还获得了红砂岩在组合加载情况下预静载应力与最终破坏强度的对应关系。

By using of the Instron electro-hydraulic and servo-controlled material testing machine and adopting low-cycle fatigue loading method, the dynamical response and failure behavior of rock under uniaxial static-and-dynamical combination loading have been tested. The tested results show that the failure strength of red sandrock under uniaxial static-and-dynamical combination loading is larger than that under single static loading, but lower than that under single dynamical loading, Young's modulus E of red sandrock is also decreasing with the increasing of static pre-load and rock shows a kind of intenerated tendency. Furthermore the relation of static pre-load and failure strength of red sandrock under combination loading has been founded.