考虑浆体黏度的泥石流流速计算方法

泥石流浆体黏度通过影响泥石流内、外部的阻力特征影响泥石流的糙率系数,泥石流糙率系数与浆体黏度之间的关系还没有基于观测数据的定量表述。通过对云南东川蒋家沟泥石流观测资料的分析,研究泥石流糙率系数与浆体黏度之间的关系,并通过回归分析得到考虑浆体黏度的泥石流糙率系数计算公式,最后基于此构建了考虑浆体黏度的泥石流流速计算公式。结果表明,随着泥石流浆体黏度的增加,泥石流糙率系数逐渐增加,浆体黏度在宏观上表现为增阻作用,考虑浆体黏度的泥石流流速计算公式改进了现有公式在计算浆体黏度较高的泥石流流速中的不足。研究结果可为进一步研究浆体黏度对泥石流运动阻力的影响提供参考,也为工程实践中的流速计算和增阻消能设计提供新的思路。

Calculation of Debris Flow Velocity in Consideration of Viscosity of Slurry

The viscosity of slurry affects the roughness coefficient of debris flow by changing the internal and external resistance characteristics of debris flow. Such influence is often neglected and has not been quantitatively expressed based on observed data. In this paper we explore the relation between roughness coefficient and viscosity of slurry based on field measurement data at the downstream channel of Jiangjia Ravine. By regression fitting we acquire the formula of calculating the roughness coefficient of debris flow in consideration of the viscosity of slurry, and further establish the mathematical relation between velocity of debris flow and viscosity. Results illustrate that the roughness coefficient of debris flow increases with the augment of viscosity of slurry. In other words, the viscosity of slurry enhances resistance in a macroscopic sense. The present formula overcomes the shortcomings of existing formulae in calculating the velocity of debris flow with high viscosity. The results provide a reference for further study of the influence of viscosity of slurry on the resistance of debris flow, and offer a new idea for calculating flow velocity and designing energy dissipation methods.