明渠水面曲线的简化计算

A Simplified Calculation of Open Channel's Water Surface Curve

工程中一般采用分段法进行明渠水面曲线的计算 .应用分段法时 ,需要计算每个流段的平均水力坡度 ,由于平均水力坡度的计算十分繁琐 ,计算工作量大 .本文采用一种简化法计算明渠水面曲线 ,不必计算平均水力坡度 ,可使计算工作量大为减少 .即用渠道的正常水深与流段的平均水深之比的x次方之值来代替平均水力坡度 .通过算例证明 ,采用简化法计算结果与分段法比较 ,其误差不到 1% 。

In gerneral,stage-method was adopted to calculate water surface curve of open channel in engineering. When we employ stage-method,it is necessary to calculate average hydraulic grade in every flow stage.Because it was fussy to calculate average hydraulic grade and workload is great,a simplified method was adopted in this article.It can reduce work-load greatly.i.e.,the value of the ratio between channel's normal water depth and flow stage's average water depth to the power x will replace average hydraulic grade.Instances prove that error didn't exceed 1%.Compared with stage-method,simplified calculation can satisfy the needs of engineering completely.