冲孔水泥土桩止水帷幕在某基坑工程中的应用

Application of curtains of punched soil-cement piles in a foundation pit

在地下水丰富的填石层中开挖基坑,止水帷幕的设计施工是个难题,在地下水为动水的深大基坑中尤为困难。常用的止水帷幕中,深层搅拌法在填石中不能成桩,压力灌浆法可控性差基本不采用,地下连续墙造价较高故较少采用;高压喷射桩经常采用,但效果通常欠佳甚至失败。某工程在海边填石层及砂砾层中,采用了一种新型的冲孔水泥土桩止水帷幕,即采用冲击的办法解决成孔问题,浇灌就地自行配制的水泥土作为桩身材料,施工简便、造价低,取得了较为满意的止水效果。

The design and construction of curtains in the foundation pit excavation in rock-fill layer abundant of water, especially under existing hydrodynamic load,are difficult.For various curtains,deep mixing is not valid in pile-forming in the rock-fill layer and the pressure grouting is not adopted because of bad controllability.The diaphragm wall is rarely applied because of high cost,and the use of high pressure jet piles proves to be deficient.The use of punched soil-cement piles (pore-forming by punching and pouring the soil-cement self prepared) in curtains in a project has been successful.The present method is satisfactory,simple and economical.