Author(s): Shan Chen; Li Chen; Jie Huang; Min Zhou
Linked Author(s):
Keywords: Moisture content; Granular; Accumulation; Stable slope angle; Internal friction coefficient
Abstract: Rock-fill dam and silt dyke can be treated as granular accumulation. Rainfall, drought, and stage fluctuation changes the moisture content of granular accumulation such as dyke, sandbar or bank slope, as well as putting the granular medium in cyclic wet-dry status. While in cyclic wet-dry environment, the mechanisms and rules of water- granular medium coaction may change, which is likely to affect the internal mechanisms, rules and critical conditions of deformation, instability, or even collapse of dyke, sandbar or bank slope. The stability of granular accumulation is intimately related to stable slope angle. Numerous researches on stable slope angle have been carried out, as well abundant achievements have been made. However, most researches focus on influencing factors and rules of stable subfluvial slope angle, few studies have been done on the non-cohesive granular medium feature changing and its effects due to cyclic wetting and drying. In this paper, the repose angle and its changing rule of different component and moisture content granular medium were studied through laboratory experiments. The result shows: within the scope of the experiments of different component granular medium, the rule that repose angle changing with moisture content is the same, the repose angle increases at first, reachs the maximum and then keeps basically stable; the maximum repose angle of granular medium of different component is similar; compared with plastic sand, the repose angle of natural sand adds slower with the increasing of moisture content; the grain size of plastic sand has a significant effect on the process of repose angle’s increasing, while the grain size effect of natural sand is smaller. Based on the experimental investigation, through mechanics analysis, considering the effect of moisture content on internal friction coefficient, a formula which contains the effect of moisture content on repose angle is preliminary established and tested combining the experimental data. The rule that repose angle’s changing with moisture content can be expressed by the formula.
Year: 2013