黄河海勃湾水利枢纽导流明渠进出口围堰施工方案优化

Construction Optimization of Cofferdams at Inlet and Outlet of Open Diversion Channel in Haibowan Water Control Project in Yellow River

黄河海勃湾水利枢纽采用明渠导流方案,原设计土石围堰防渗结构采用上部黏土斜墙+下部高喷防渗墙,但由于移民征地及气候影响,工程未能如期开工。为避免对导流明渠施工工期产生较大影响,综合考虑多种因素提出了围堰防渗体优化方案,即取消施工资源不足的下部高喷防渗墙的防渗体,采用导流明渠开挖壤土料进行围堰背水侧填筑形成防渗体,通过增加基坑排水设备的方式解决堰基渗水问题,并在围堰填筑完成后充分利用当地房屋拆迁的建筑垃圾对堰体迎水面进行防冲防护,为导流明渠基坑施工创造了条件。

The open channel is originally designed in the fiver diversion of Haibowan Water Control Project in Yellow River, in which, the impervious structure of earth-rock cofferdams at the inlet and outlet of channel is the combination of upper clay inclined wall and lower high-pressure grouting cutoff. Because of influenced by the resettlement and the climate, the construction of cofferdams is postponed. For guaranteeing the excavation of open channel, the impervious structure of cofferdams is optimized. The lower high-pressure grouting cutoff is canceled and the excavated soil material of open channel is poured at the land side of cofferdam as impervious body. The water seepage in foundation pit is pumped out by increasing drainage capacity, The water face of cofferdam is also protected by the wastes of local housing demolition for erosion control. The optimization guarantees the excavation of open channel.