基于能量耗损原理的泥石流分界粒径确定方法

本文以泥石流固相与液相的能坡损失之和来表达泥石流运动能量耗损总值,并基于最小能耗原理提出了泥石流固、液两相分界粒径的确定方法.通过在云南蒋家沟实施6组现场泥石流模拟试验,结果表明试验沟道的泥石流分界粒径处在5～6mm之间,与前人成果基本相符,同时分析了分界粒径与最小能量耗损和容重之间的变化规律,即分界粒径随着最小能坡损失和容重的增加而呈缓慢的增大趋势等,为建立了非均质黏性泥石流动力学模型奠定了基础.

Method for determining the critical grain size of viscous debris flow based on energy dissipation principle

By means of theoretical analysis the expressions of hydraulic energy gradient for liquid phase and solid phase were deduced respectively and the total hydraulic energy dissipation of debris flow was regarded as the sum of the losses of these two energy gradients. On this basis, a method for determining the critical size of vicious debris flow was established by applying the principle of minimum energy dissipation. The verification experiment carried out in Yunnan Province, China, showed that the predicted result is in good agreement with observed data. The critical grain size is 5-6mm. It tends to gradually increase with the increases of minimum energy dissipation gradient and specific weight of flow. This provides the solid basis for establishing dynamic model for the heterogeneous viscous debris flows.