非标准马蹄形断面隧洞的水力计算研究

马蹄形过水断面为无压隧洞较常采用的形式,但断面形式复杂使其水力计算变得十分困难。通过数学推导,给出了6圆弧马蹄形断面的水力要素计算公式;分别采用谢才公式和临界流方程,推导了顶拱和上侧拱所对应的圆心角的迭代公式,进而给出了正常水深和临界水深的计算公式,并将之应用于引汉济渭工程秦岭无压隧洞的水面线计算之中。结果表明:水面线形态与定性分析结果相符,计算简单、结果可靠,可为工程实例中类似断面形状的水力计算提供参考。

Study on hydraulic calculation of non standard horseshoe section tunnel

Horseshoe cross section is commonly used for open-channel flow tunnel, but the section make hydraulic calculation become difficult because of its complex. The paper gave the formulas of hydraulic elements for 6 cambered horseshoe sections through mathematical deduction. It used Chezy formula and critical flow equation to deduce the iterative formula of corresponding central angle of top arch and upper arch, then gave the calculation formula of normal depth and critical depth.The method is applied to calculate water surface profile in Qinling tunnel of Hanjiang-to-Weihe water project.The result shows that the morphology of water surface profile meet the qualitative analysis results.The calculation process is simple and reliable and can provide reference for the hydraulic calculation of other project.