Abstract: A deep excavation case history of the Fenghuangxian Commercial Development Project of Zhonghai Group in the Hexi Area of Nanjing City is presented in this paper. The design and construction aspects of this project are introduced. The applications of double ring bracing system in the soft soil and large scale excavation are also discussed. The construction monitoring results indicate that the double ring bracing system can provide a better control in the deep excavation deformation. This method has also the advantage of the earth excavation and the structural construction of the tower buildings.

Key words: Deep Excavation, Soft Soils, DoubleRing Bracing System