摘要
弯道超高是泥石流运动的显著特征。以往研究认为弯道超高完全是由于泥石流的离心运动造成的,未考虑泥石流在弯道运动时的冲起爬高效应。本文假设弯道超高和爬高分别由泥石流沿弯道的切向和法向速度引起,根据弯道处速度矢量三角形和圆弧三角形的几何相似关系,推导了考虑爬高效应的泥石流弯道超高公式。该公式依赖于弯道的内外曲率半径比、泥石流速度和沟壁倾角,适用于弯道圆心角小于60°和沟道较宽的情形。经云南东川蒋家沟的野外实际调查数据以及其他文献中的数据验证,与实测值误差较小,可用于泥石流弯道爬高的实际计算中。
Debris flow exhibits a noticeable super-elevation when it passes through a meandering stream.Previous studies attributed the super-elevation completely to debris-flow centrifugal motion in bends of thestream and neglected the run-up effect on it. Assuming the super-elevation and run-up caused respectivelyby tangent and normal velocity components of debris flows along the bends,a new formula for calculatingthe super-elevation is derived from the combination of the traditional forced vortex equation and the veloci-ty head equation by virtue of geometric similar relationship between triangles of velocity vector and thecurved channel. The total super-elevation is a function of flow velocity,ratio of internal and external curva-ture radiuses,and bank inclination angle. The new formula is applicable to the wide curved channel ofwhich turning angle is less than 60°. The relative error between the calculated and field or experimentalmeasured values is less than 17 %,which is acceptable for practical purpose.
出处
《水利学报》
EI
CSCD
北大核心
2015年第2期190-196,共7页
Journal of Hydraulic Engineering
基金
中国科学院重点部署项目(KZZD-EW-05-01)
国家自然科学基金重点项目(41030742)
国家自然科学基金面上项目(41371039)
关键词
弯道超高
爬高
泥石流
流速
super-elevation
run-up
debris flow
velocity
