颗粒形状变异对砂性类岩堆体地层宏观力学性能及变形特征的影响研究

Effects of Grain Shape Variation on the Macro Mechanical and Deformation Properties of Sandy Talus-Type Medium

类岩堆体既不属于岩体,也不属于土体,且不同的类岩堆体围岩在机械开挖或爆破开挖扰动下的力学响应不同。本文针对典型的非连续介质—砂性类岩堆体,通过离散元数值试验研究了颗粒形状变异对其宏观力学性能及变形特征的影响规律。结果表明:颗粒形状越扁,砂性类岩堆体的整体抗压缩能力越弱,在相同的围压下会被压缩得更密,整体强度也有一定程度的提高;颗粒凹凸性越大,砂性类岩堆体的整体抗压缩能力越强,在相同的围压下更难被压密,凹凸性指数对整体强度几乎没有影响。

The talus-type medium belongs to neither rock nor soil categories. Different types of talus media will behave differently subject to either mechanical or explosive excavation. Of the talus media, the sandy type talus is a typical discontinuous medium. This study investigated the effects of shape variation on the macro mechanical and deformation properties of sandy talus-type medium using the element modeling (DEM). The simulation results show that the overall compressive rigidity decreased with increasing elongation, while the overall strength increased with increasing elongation under the same confining pressure. The sample was compacted more densely as elongation increased. The compressive increased and it was more difficult for the sample to be compacted. Nevertheless, the convexity did not show obvious influence on the sample overall strength.