Debris flows are a type of fast landslides where a mixture of soil and water propagates along narrow channels. The main characteristics are (1) important relative displacements between the solid and fluid phases, and (2) development of pore-water pressures in excess to hydrostatic. The ratios between vertical and horizontal displacements of the flow, from the triggering point to the deposition, indicate that friction angles are much smaller than those measured in laboratories. Debris flows are modeled as two phases flow, but implementing pore-water pressure is an important issue. The purpose of this paper is to improve the existing two phases debris flow models by implementing pore-water pressures in excess to hydrostatic. It is found that pore pressure evolution depends on consolidation, changes in the flow depth, and changes and gradients of porosity. The proposed depth integrated mathematical model is discretized using two sets of SPH nodes (solid and fluid), with a set of finite difference meshes associated with each solid material SPH point. The paper presents two examples from where it is possible to gain insight into the differences between the models (with and without excess pore water pressure).

泥石流是一种快速的滑坡，土壤和水的混合物沿着狭窄的通道扩散。主要特征是（1）固相和液相之间的重要相对位移，以及（2）超过静水压力的孔隙水压力的发展。从触发点到沉积物的垂直和水平位移之间的比值表明，摩擦角比实验室中测得的摩擦角小得多。泥石流被建模为两相流，但是实现孔隙水压力是一个重要的问题。本文的目的是通过实施超过静水压力的孔隙水压力来改善现有的两相泥石流模型。发现孔隙压力的变化取决于固结，流动深度的变化，以及孔隙率的变化和梯度。使用两组SPH节点（实体和流体）以及与每个固体材料SPH点关联的一组有限差分网格来离散化建议的深度集成数学模型。本文提供了两个示例，从中可以深入了解模型之间的差异（有或没有多余的孔隙水压力）。