在泥石流运动过程中,途经的松散表层材料可能会因泥石流的剪切作用而产生运动,从而形成对沿程地表的侵蚀。为模拟泥石流沿程侵蚀动力过程,并研究沿程侵蚀对泥石流动力过程的影响,结合泥石流动力模型理论和近似Riemann解的HLL有限体积数值离散方法,对一个典型的沿程侵蚀的历史泥石流进行反演计算分析。考虑泥石流动力过程中的沿程侵蚀作用,再现泥石流的动力过程,计算结果与实际泥石流的致灾范围吻合较好,从而验证动力模型理论和数值求解的有效性。同时,与未考虑沿程侵蚀作用的计算结果作比较,结果表明沿程侵蚀作用会增加泥石流的运动体积,从而显著影响泥石流的动力过程,使其具有更大的危害性和更强的破坏力。
The unconsolidated surface material along the way may have a shear failure and slide with the land during the motion process,as a result,the entrainment of path material on the surface is formed. In order to carry out the simulation of dynamic process of entrainment along the way and study the influence of this entrainment on dynamic process of debris flow,the back analysis is made to study a typical historical debris flow with its erosion along the way,by combining debris flow dynamic model theory and the method of finite volume discretization based on the approximate Riemann solver of HLL scheme. The calculation has considered the entrainment action during the dynamic process of debris flows and reappears the whole process. The calculation results which are identical to actual disaster-caused area confirm the effectivity of the dynamic model theroy and the numerical solution. At the same time,compared with the results which have no consideration of entrainment,it is can be seen that the entrainment action can increase the motion volume of debris flow and enhance the motility so that the dynamic process of debris flows would be greatly influenced;and as a result,the debris flow will be more destructive and harmful.