Analysis And Application On Water-resisting Curtain For Deep Excavation In Beijing

With the rapid development of urban construction, more and more foundation pit engineering arises. In the deep foundation pit engineering design and construction,groundwater is an important factor which influences the stability of foundation pit safety and stability. Sharp precipitation may reduce the foundation pit water level, but at the same time will cause settlement of surrounding ground subsidence, pipeline rupture, housing cracking and even collapse. And stop water heavy curtain set can prevent permeable layer under the action of water level difference, both inside and outside the pit to pit seepage, and prevent the resulting sand flow of seepage damage,especially in the complicated surroundings areas, water stop curtain can avoid ground settlement outside the foundation pit due to ground water levels fall, and ensuring foundation pit draw internal basic dry, convenient for construction.This article analyzes the present situation of domestic and foreign water stop curtain, focusing on the most widely used form of water stop curtain, including high pressure jet grouting pile and stop water heavy curtain stirring pile and stop water heavy curtain stirring continuously and stop water heavy curtain wall and its construction process and the mechanism of pile. In addition, the design method of water stop curtain is analyzed in theory, mainly studies the calculation model of water pressure and seepage failure mechanism, summarizes the calculating formula of the depth and thickness of the water stop curtain.Finally, on the basis of Wangjing K7 project engineering instance, the rotary spray water stop between pile design and construction is analyzed, and put forward the pros and cons of rotary spray water stop curtain between piles, and summarizes the factors affecting between stop-water effect of jet grouting pile,including the engineering geological conditions, the quality control in the process of construction, the influence of cement mortar, etc. Through the analysis of theconstruction work, to learn more about the applicability of all kinds of water stop curtain in Beijing area, for after the still water of foundation pit engineering design and construction to provide certain theory reference and guidance.