尾矿库明渠排洪系统调洪演算方法

Flood Regulating Calculation Algorithm of Open Channel Drainage System of Tailing Ponds

在尾矿库闭库治理、截洪型新建尾矿库工程中,明渠作为排洪系统应用较为广泛。排洪系统是尾矿库的重要构筑物,直接关系到尾矿库工程的经济与安全。目前,明渠应用存在的问题:设计流量直接按洪峰流量计算,造成明渠设计断面偏大;明渠缓流状态时未考虑淹没系数对流量的影响,存在防洪安全隐患;明渠急流状态未设置过渡段,致使断面设计偏大。针对以上问题,利用临界底坡将明渠进口的流态分为自由出流、淹没出流,给出了矩形断面进口自由出流状态下的临界水深、临界流速、临界底坡的计算公式;根据明渠进口的流态,分别给出了明渠缓流、急流泄流关系的计算步骤;根据区域洪水过程线、调蓄库容曲线及泄流关系曲线,进行了尾矿库调洪验算。

In the closed treatment of tailing ponds and the intercepting flood type new tailing pond project,open channel has been widely applied as drainage system.Drainage system is an important struc-ture of tailing pond,it is directly related to economic and security engineering of tailing pond.At pres-ent,there are several problems of the application of open channel are existed：flood regulating calculation is not conducted,design of open channel flow is directly calculated by peak flow,resulting in open chan-nel cross -section design is too large;the influence of the submerged coefficient flow is not considered in channel slow state,so,flood control safety hazards are existed;the transition section is not set in channel rapids state,resulting in the design of cross section is too large.In view of the above problems,the flow of imports of open channel is divided into free flow submerged discharge flow by using the critical bottom slope.The calculation formulas of critical depth,critical flow velocity and critical bottom slope are given under the state of rectangular import free flow.According to the flow state of the imports of open channel, the calculation steps of the discharge relationship between slow flow and jet flow are given respectively. The flood regulating calculation is conducted based on the regional flood process line,storage capacity curve and discharge curve of tailings.