泥石流中大颗粒的起动与水流条件的关系  

Relationships between starting motion of large-sized particles in debris flow and water flow condition

作　　者：汤碧辉 孙红月[1] TANG Bihui SUN Hongyue(Ocean College, Zhejiang University, Hangzhou 310058, China)

机构地区：[1]浙江大学海洋学院,浙江杭州310058

出　　处：《自然灾害学报》2017年第3期132-138,共7页Journal of Natural Disasters

基　　金：国家自然科学基金项目(41272336)~~

摘　　要：我国常年遭到泥石流灾害的侵袭,由此造成的损失不计其数。泥石流拥有巨大冲击力,其中大部分来自其中裹挟的大颗粒。文中对稀性泥石流中大颗粒的起动与水流条件的关系进行了研究。以斜坡上的球形颗粒为研究对象,分析了球体受到的上举力、推移力、有效重力;使用概率论的理念解决了颗粒在斜坡上的随机分布问题,得到了各个外力的力臂期望,并求解了颗粒临界起动时的力矩平衡方程,获得了颗粒起动的作用流速,进而将之转化为断面平均流速,由此得到了稀性泥石流中大颗粒的起动与水流条件的关系。这对泥石流防治工程,特别是排水设施的设计具有一定参考意义。Debris flow occurs frequently in China, and that leads to great properUes loss. Debrts flow contains tre- mendous impact, most of which comes from large-sized particles. This paper investigates the relationships between starting motion of large-sized particles and water flow condition. The study is focused on one spherical particle on the ramp, and analyzes the particles＇ forces, including lift force, push force and effective gravity. We solve the particles＇ random distribution on the ramp through probability method, and infer mathematical expectation of forces＇ arms. Additionally, the moment equilibrium equations of starting condition for grains are solved. Therefore we obtained the threshold velocity of the particle, which can be transformed into mean velocity at across-section. In the final, the relationships between starting motion of large-sized particles in debris flow and water flow condition are achieved, which provides a reference for building design of debris flow prevention, especially for the drainage device design.

关 键 词：泥石流 大颗粒起动 概率论 起动流速 安全流量 

分 类 号：P642.23[天文地球—工程地质学] X43[天文地球—地质矿产勘探]