摘要
减压井是堤坝防渗工程的主要手段之一,其机械淤堵和化学淤堵是关系减压井减压效果的重要因素。广东省北江大堤已实施383口减压井,分布于石角、大塘、黄塘、西南等堤段。其中石角堤段建有147口减压井,建设年代由1966至2001年,成孔工艺有回旋钻泥浆护壁和钢套管振动沉管法,反滤方式有开孔缠丝和开槽法,汛期减压井出水量各不相同,减压效果也存在较大差异。根据汛期减压井实测流量和测压管数据、现场抽水试验和现场试验井的研究、数值模拟分析,得出北江大堤减压井以机械淤堵为主的结论。汛期70%减压井出水满足设计要求的莲藕塘段,减压效果明显;而只有20%减压井满足要求的横基段,减压效果差,存在安全隐患;应根据地层特性研究并选择合适的成井工艺,保证减压井的成活率,确保大堤安全。
Relief well is one of the main reinforcement measures of a levee.Effects to relieve pressure depend on mechanical clogging and chemical clogging in a relief well.In North River Levee,there are 383 existing relief Wells,located in Shijiao,Datang,Huang-tang,Xinan levee reaches etc.,of which 147 relief wells in Shijiao Levee were constructed during 1966-2001.The techniques of drilling holes contain slurry-supported drilling method and steel-casing vibrating sinking method,while the filter hole can be grooved or wrapped by yarn.For the different outflows of wells,the effect to relieve pressure varies during flood season.According to the measured data of piezometric heads and discharges of relief wells during flood season,pumping tests,field test results and numerical simulations,the conclusion that the mechanical clogging is a main measure can be obtained.As to relief wells in North River Levee,the cases of 70% outflows of wells show perfect effect to relieve pressure at Lianoutang Segment and,only the cases of 20% show weak effect and safety hidden troubles at Hengji Segment.So according to the characteristics of strata,we should choose appropriate well-drilling techniques to ensure the effect of relief wells and the safety of levees.
出处
《长江科学院院报》
CSCD
北大核心
2010年第12期52-58,共7页
Journal of Changjiang River Scientific Research Institute
关键词
水利工程
堤坝
渗流
减压井
hydraulic project
levee
seepage
relief well
