泥浆对黏性碎屑流坡面运移过程的影响

Influence of Mud on Migration Process of Viscous Debris Flow

[目的]分析泥浆对黏性碎屑流坡面运动形态、横向宽度、纵向运动距离及运动速度影响,为此类灾害防治提供参考。[方法]制作黏性碎屑流实验模型,将不同含水率成都黏土泥浆与粗颗粒混合,制备黏性碎屑流试样,开展系列黏性碎屑流物理模型试验。[结果]随泥浆密度增大,粗颗粒间粘连作用增强,其运动形态由无黏碎屑流向黏性碎屑流再到整体块状运动形态转变;坡面横向宽度、纵向运移距离和速度随泥浆密度增加而减小;不同密度泥浆组成黏性碎屑流运动过程具有分类现象:密度低于1.413g/cm3时,速度随时间增长快,变化梯度较稳定;密度大于1.413g/cm3时,运动速度变化过程可分为2个阶段:前期速度随时间增长慢,变化梯度较小;后期速度随时间增长快,且较前阶段变化梯度有所增大,各高密度泥浆情况趋于一致。[结论]泥浆影响黏性碎屑流运移形态和运动过程。

[Objective]The aim of the study is to analyze the influence of mud on the moving ways,width and longitudinal distance and velocity of viscous debris flow on slope,and help to provide the references for disaster prevention.[Methods]The experimental model was built for viscous debris flow,and a series of model experiments were carried out through the device.The viscous debris flow composed of Chengdu clay mud and coarse particles.[Results]The adhesion force between the coarse particles increased,and the movement patterns changed from the inviscid debris flow to the viscous debris flow,and to the massive sliding with increasing mud density.The width and distance on slope decreased with increasing mud density.The migration process could be differentiated according to mud density.The velocity increases rapidly and the gradient is large when mud density was lower than 1.413g/cm^3.The migration process can be divided into two stages when mud density was higher than 1.413g/cm^3,the velocity increased slowly and the gradient changes little in the first stage but the velocity increased quickly,and the gradient changed quickly in the second stage.[Conclusion]The mud affects the movement pattern and the moving process of viscous debris flow.