Construction of a Foundation Pit without Dewatering

In Beijing, dewatering has been strictly prohibited in foundation-pit excavation since March 1, 2008. Therefore, the deep foundation pit has to be constructed underground water level, which makes the construction of the water-resistant curtain and anchor quite difficult in granular soil. This paper introduces the construction of a foundation pit of underground garage with the excavation depth of 20.6 m. By improving construction techniques, a water-resistant curtain was constructed with good performance under a water head of up to 6 m in a granular soil layer with high permeability. The anchoring force is guaranteed in the case that cement slurry is lost after the water-resistant curtain is perforated underground water level. The project is a successful example of foundation pit engineering construction in the Beijing area.