| 引用本文: | 贺正宇,何武全,李 渤,等.抛物线形底梯形渠道水力最佳断面计算方法[J].灌溉排水学报,2025,44(12):39-44. |
| HE Zhengyu,HE Wuquan,LI Bo,et al.抛物线形底梯形渠道水力最佳断面计算方法[J].灌溉排水学报,2025,44(12):39-44. |
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| 摘要: |
| 【目的】解决梯形渠道水力效率与抗冻胀能力较差的问题，同时改善抛物线形渠道存在的渠口狭窄、深度过高、难以适应大中型渠道工程应用的缺陷，提出一种抛物线渠底与梯形边坡相结合的复合断面渠道。【方法】建立了该复合断面渠道水力参数的数学表达式，以抛物线段水深为单一变量，通过微分方法构建数学模型以寻求最优解，确立抛物线段与梯形段水深的关联方程，推导出该复合断面渠道水力最佳断面的水深、过水断面面积、湿周长度及水面宽度的计算方程。【结果】通过工程实例计算，当输水流量为12 m3/s、糙率系数为0.015、渠道底坡为1/6 000时，抛物线形底梯形渠道在水力最佳断面条件下，设计水深为2.838 m，水面宽度为6.122 m，湿周长度为8.717 m，过水断面面积为11.554 m2。在相同条件下，相较于传统梯形断面，该新型复合断面过水断面面积缩减1.28%，湿周减少3.20%；相比抛物线形断面，过水断面面积降低0.85%，湿周缩短1.68%。【结论】该复合断面结构在节省土地资源和降低工程成本方面的优越性，为渠道工程提供了更优的断面设计方案。 |
| 关键词: 抛物线形底梯形渠道；复合断面渠道；水力最佳断面；微分法；水力计算 |
| DOI：10.13522/j.cnki.ggps.2025188 |
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| Method for optimizing hydraulic sections of composite trapezoidal-parabolic channel |
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HE Zhengyu, HE Wuquan, LI Bo, ZHAO Keyi
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1. Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education,
Northwest A&F University, Yangling 712100, China; 2. Power China Northwest Engineering Corporation Limited, Xi’an 710065, China
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| Abstract: |
| 【Objective】Traditional trapezoidal channels are less hydraulically efficient and prone to frost heave, while parabolic channels have narrow openings and excessive depths making them unsuitable for use in medium-to- large-scale engineering projects. To address these limitations, we propose a composite channel with a parabolic bottom section for improving hydraulics and a trapezoidal slope for adaptability to large-scale project. 【Method】A hydraulic calculation model was developed for the composite channel, with water depth in the parabolic section as design variable. Optimal combination of the trapezoidal slope and parabolic section was determined using differential methods to minimize the hydraulic resistance and cross-sectional area. From this optimization, we established the correlations between water depth in the parabolic section and the trapezoidal section, and calculated the optimal water depth, cross-sectional area, wetted perimeter and water surface width. The model was validated against experimental data. 【Result】Under operating conditions of flow rate of 12 m3/s, roughness coefficient of 0.015, and channel slope of 1/6 000, the optimal composite channel had the following hydraulic parameters: total water depth was 2.838 m, water surface width was 6.122 m, wetted perimeter was 8.717 m, and cross-sectional area was 11.554 m2. Compared with traditional trapezoidal channel under the same operating conditions, the composite channel reduced cross-sectional area by 1.28% and wetted perimeter by 3.20%, while compared with traditional parabolic channel, it reduced cross-sectional area by 0.85% and the wetted perimeter by 1.68%. 【Conclusion】The proposed composite trapezoidal-parabolic channel integrates the advantages of both traditional designs. It improves hydraulic efficiency and is applaudable to medium-to-large-scale hydraulic engineering projects. The reduced cross-sectional area and wetted perimeter in the composite channel save land occupation and reduces engineering costs, thereby providing a practical and optimized alternative for channel engineering applications. |
| Key words: parabolic-bottom trapezoidal channel; composite cross-section channel; hydraulic optimum section; differential method; hydraulic calculation |
