笔者通过南宁市人大代表活动中心水渠工程实例,阐述了矩形暗渠洪状态总是流量从零变化到最大,又从最大变化到零的过程,兼有明渠流与暗管流的水力特征,对如何保持明渠流速适宜又控制百年一遇洪水流量从最大变化到临界点暗管允许流速范围,进行了优化设计剖析;其內容可供从事设计、施工、管理和教学的给排水同行参考。 The author through Nanning Municipal People’s Congress Representative Center drains project example, elaborates the flood condition of rectangular underdrain flow is always from zero to the maximum change, but also from maximum to zero process, both the open channel flow and the flow of hydraulic characteristics of pipe, how To maintain the open channel flow rate is appropriate and to control the once in a century floods from the maximum change to the critical point of the allowable flow rate range, the optimal design analysis; its content for the design, construction, management and teaching of water supply and drainage counterparts reference.