层状颗粒柱体崩塌-堆积过程研究

碎屑流具有高速度、冲程远、危害范围广等特点,颗粒粒径被认为是影响其运动距离的重要因素之一。为了对碎屑流进行有效的预测和防范,基于单面临空下不同分层堆积模式颗粒柱体的一系列崩塌运动物理试验对其崩塌-堆积过程进行了研究。结果表明:不同分层堆积模式颗粒柱体崩塌后,颗粒的堆积层序和试验前颗粒初始堆积层序保持一致;崩塌后的颗粒堆积层序和试验前颗粒初始堆积层序有关;不同粒径的颗粒相互间运动时,粒径较小的颗粒填充到大颗粒间的空隙之中,并起到润滑作用;颗粒柱体在单面临空面方向崩塌时,颗粒运动方向呈放射状,堆积平面形式是"圆形态";分别以d_7颗粒为顶层和d_(13)颗粒为顶层时,d_7颗粒最远堆积长度比d_(13)的高约6.3%;顶层颗粒(d_7颗粒)运动能力越强,则最终的堆积范围越大,底层颗粒(d_(13)颗粒)的运动能力,对整个堆积体最终堆积范围影响相对较小。上述规律可应用于层状危岩体崩塌过程及其颗粒堆积范围的研究。

Study on collapse-deposit process of layered granular column

The debris flow has the characteristics of high flowing velocity，long travel distance and wide hazard range，while the particle size is considered to be one of the important factors affecting the movement distance of debris flow． In order to effectively predict and prevent the debris flow，its collapse-deposit process is studied herein through a series of physical experiments made on the collapse movement of the granular column based on different depositing modes under the condition of single free-face． The study result shows that after the collapse of the granular column under different layered deposit modes，the granular deposit layer sequence is consistent with the initial granular deposit layer sequence before the experiment，while the granular deposit layer sequence after the collapse is related to the granular deposit layer sequence before the experiment． During the mutual movements of the granules with different particle sizes，the granules with smaller particle size fill into the voids among the larger ones and play the role of lubrication． When the granular column is collapsed in the direction of the single free-face，the direction of the movement of the granule exhibits a radial shape with the pattern of the deposit plane of a circle shape． When the top layer consists of d7 granules and d13 granules，the farthest depositing length is 6. 3% higher than that of the d13 ． The stronger the moving capacity of the granule of the top layer is，the smaller the relative impact on the final depositing range of the whole deposit body is to be． The above-mentioned law can be applied to the study on the collapse process of the layered dangerous rock mass and its granular depositing range．