中文摘要：

侧堰安装在渠道侧边,常用来宣泄水流,控制水量,具有结构简单、量水精度较高等优点。若能对侧堰量水时主、侧渠道分流比例与上游来流结合起来研究,则侧堰可同时完成量水与分水两种功能,实现一物多用,经济实用。本文对具有不同堰顶角度（θ=0°,3°,6°,9°）的梯形侧堰进行试验,测量了各工况下侧堰附近的水深等水力因素,获得了侧堰附近水面线,计算了不同堰顶角度下的分流比例,研究了流量系数与其影响因素之间的关系。结果表明：同一堰顶角度下,分流比例随着上游来流流量的增大而增大,不同堰顶角度下,分流比例变化范围随着侧堰堰顶角度的增大而减小;获得的分流比例公式精度较高,决定系数达到0.921;获得的含有P/h1和Fr1的流量系数公式最大相对误差为8.06%,满足测流精度要求。该文章对侧堰量水与分水功能的结合进行了初步探索,为侧堰的研究提供了新的方向与依据。

英文摘要：

Side weirs of simple structure and high accuracy are usually installed along the side of main channels to spill and control water flow. Convenience and economic benefit in application could be achieved by combining their roles in flow rate measurement and flow division. In this study, we have conducted a laboratory experiment of trapezoidal sharp-crested side weirs of different crest angles（0°, 3°, 6° and 9°） in a rectangular channel under different discharges, and analyzed their flow characteristics and influencing factors. For different crest angles of side weirs, water surface profiles were measured and flow division ratios were calculated, and relationship of discharge coefficient versus influencing factors was examined. Results show that the flow division ratio at a fixed crest angle increases with the increasing inflow rate and the variation range of flow division decreases with the increasing crest angle. A flow division formula of high accuracy with a correlation coefficient of 0.921 was obtained. We also formulated a discharge coefficient formula by adding two inflow parameters of P/h1 and Fr1 and achieved a relative error of less than 8.1%, meeting the accuracy requirement of practical measurements. This work is a preliminarily study on the combined roles of flow rate measurement and flow division and it would provide a new direction for further study on side weirs and their engineering application.