流溪河大坳拦河闸坝历史险情分析及启示

Learn from Two Accidents of Daao Sluice Across Liuxi River

广州市流溪河大坳拦河闸坝2006年6月出现重大险情,主要是由于下游河床下切,致使工程现有消能设施起不到应有功效,在高速水流冲刷及渗流的联合作用下,下游海漫由下向上发生大面积坍塌破坏,严重影响闸坝安全。除险加固工程于2007年初完工,但在2008年6月28日下游消力池连接段混凝土板又发生掀起破坏,主要原因是上游防渗帷幕达不到设计目的,下游排水孔排水能力不足,导致混凝土板底扬压力过大,最终发生掀起破坏。可见,对于强渗透地基的闸坝工程,渗流控制设计合理与否将直接影响到建筑物的安全。

A major accident occurred at the Daao sluice across the Liuxi River in June,2006.Investigations found that the failure is mostly due to the downstream river bed incised,which caused the disfunction of the existing energy dissipaters.The soil erosion caused progressive collapse in the downstream stone apron,which posted severe threat to the safety of the sluice structure.The reinforcement project was accomplished at the beginning of 2007.However,on June 28,2009,there was another major uplifting failure of the downstream stilling pool linkage section concrete section.This was found to be caused by the inadequacy of the upstream grout curtain.In addition,the drainage capacity of the downstream installed drainage holes was inadequate.These combined effects result in excessive uplifting pressure,which ultimately led to the uplifting failure.Lessons from these failures point to the importance of proper upstream seepage cut-off structure and downstream drainage measures to the safety of sluices seated on site with high rate of ground seepage.