河湾水流与河床冲淤综合分析

本文在两个弯道模型试验基础上［１，２］，综合分析了国内外的有关研究成果。文中首先阐明河流蜿蜒弯曲的必然趋势和河湾内环（副）流伴随主流形成螺旋流动前进的特征，并对弯道内主流位向变化、环流强度、水面横比降等作了分析，推荐了计算公式。其次，对河湾水流的横断面流速分布和沿河宽的单宽流量分布给出了计算方法，并分析求得了河湾冲刷深度的公式；依此可以计算河湾冲淤河床的平衡断面。

Synthetical analysis of flow in river bend and bed scouring or silting

Based on two model tests of flow in curved channel and referred to some studies for the country and for abroad summarized and analyzed the flow around river bend. Firstly this paper describes the evitable tendency for the meandering flow of natural river and the characteristics of spiral flow in river bend forming by circular secondary flow with principal flow. The change of direction and position of principal flow, the intensity of circular flow,the transverse slope of water surface across river bend etc.were analyzed and the calculation fomulas were derived. Secondly the calculation method for sectional velocity distribution and unit discharge distribution along river width are given and calculation formula of scouring depth in river bend is obtained analytically. So we can calculate the equilibrium cross section for scouring and silting in river bend by these formulas.