板桥河闸扩建工程深基坑施工降排水研究

复杂地质条件下的水闸扩建工程,在原水闸拆除及深基坑降排水施工方案编制时,既应考虑老闸拆除对保留部分结构的影响,又要考虑深基坑开挖及施工降排水对老闸保留部分结构及周边环境的影响。本文采用减压降水井+减压降水导渗管组成减压降排水装置联合降排水方案,减压降水井和减压降水导渗管相连通,地下水流向减压降排水装置中,当地下水上升到控制水位时,减压降水井中的水泵自动抽水外排,使基坑底部动水力方向由向上减小为向下或持平,使深基坑基底无隆起、边坡稳定,降排水得到有效控制,老闸底部地下水位保持稳定,老闸室结构完好。

Research on construction draining water of deep foundation pit in Banqiaohe sluice extension project

When the scheme of original sluices demolition and construction of deep foundation pit draining is prepared for lock expansion project under complex geological conditions, the effect of demolition on old gate structure as well as effect of the deep foundation pit excavation and drainage on the retain part of the structure and the surrounding environment should be considered. The joint draining scheme of drainage device which is composed of reducing precipitation well and reducing rainfall infiltration pipe is adopted. Reducing precipitation well is connected with reducing precipitation guide tube. When the groundwater goes up to the control water level, the water pump in the dewatering well will automatically pump out the water, so that the direction of the hydrodynamic force of the bottom of the foundation pit can be reduced from up to down or flat, so that the deep foundation pit flat, slope stability, reducing drainage is effectively controlled. The underground water level at the bottom of old gate remained stable, and lock chamber structure is intact.