无帷幕深开挖降水工程实践及问题探讨

为处理西气东输黄河北岸非开挖铺管工程水平定向穿越钻孔断脱事故,需在无帷幕等任何人工隔水条件下开挖一深基坑进行降水.根据场地的岩性组合、水文地质条件、基坑形状、深度和开挖方案等特点,采取了三层环形管井井点降水为主和轻型井点降水为辅的降水方案,克服了工程时间紧、工程量大、提供勘察资料差、水文地质条件复杂等问题,完成了降水、开挖、管道连接和场地恢复工作,为类似项目提供了借鉴.

Practice & Discussion on Non Curtain Deep Excavating Dewatering Engineering

In order to process break-off accident in north bank of the Yellow River non-excavating piping of the west-east natural gas transfer engineering by the use of horizontal directional underwater crossing drilling, a deep excavation is needed for dewatering without artificial exclusion of water any thing like curtain barrier. According to site lithologic association, hydrogeologic condition, excavation shape, depth and excavating scheme, three layered annular Abyssinian well point dewatering is mainly used, and assisted with light well point dewatering. Thus problems of urgent task, large engineering work load, poor prospecting data and complicated hydrogeologic condition were overcome, tasks of dewatering, excavating, piping and site restoring were fulfilled. It can be used for reference to similar projects.