普通城门洞形隧洞正常水深的直接计算方法  

Direct calculation method for normal depth of arched section tunnel

作　　者：张宽地[1] 吕宏兴[1] 王光谦[2] 傅旭东[2] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,杨凌712100 [2]清华大学水利水电工程系水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《农业工程学报》2009年第11期8-12,共5页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家973计划课题(2007CB407201);国家自然科学基金重点项目(40335050);西北农林科技大学创新团队建设计划(01140202)

摘　　要：普通城门洞形过水断面是泄洪隧洞和灌溉引水隧洞较常采用的断面形式之一,其水力计算中的正常水深求解无显函数形式的表达公式。传统的试算法或查图法不仅计算过程繁琐,而且计算精度不高。该文通过对城门洞形断面均匀流方程进行数学变换,并对引入的无量纲参数与相对正常水深的关系进行分析及计算,应用逐步优化拟合原理进行拟合,得到了普通城门洞形断面均匀流水深的直接计算表达式。实例计算及误差分析表明:在工程实用范围内(正常水深与拱顶半径之比在0.20到1.55之间),直接计算公式最大相对误差不超过0.24%。且该式具有物理概念清晰明确、公式形式简捷等优点,可为工程设计及水工设计手册的编制提供有益的参考。The arched section is one of the usually adoptive section shapes in flood discharge tunnels and irrigation tunnels, but the analytic expression of normal water depth for this section is not explicit. Though the conventional trial and error method or the graph method can be implemented, it is time-consuming and imprecise. The uniform was transformed flow equation into its equivalence, and then the relationship between the relative normal water depth and the introduced dimensionless parameter was analyzed. Finally, by fitting the relationship based on the theory of optimization and regression, a direct expression for calculating the normal water depth of arched section channel was proposed. The practical example and error analysis illustrated the validity and effectiveness of the proposed direct expression. The absolute value of the maximum relative error was not greater than 0.24 percent among the utility range of engineering （the ratio of normal water depth to arch radius was from 0.20 to 1.55）. The proposed method is clear in course, simple in calculation, and can be regarded as a useful supplement to the engineering design and the compilation of the hydraulic structure design handbook.

关 键 词：水力模型 水工结构 计算 正常水深 城门洞形断面 

分 类 号：TV131.4[水利工程—水力学及河流动力学]