Abstract: The safety of the deep excavation is one of the important factors in the urban construction. Conventional deep excavation support analysis methods are equivalent bean method; elastic beam method and finite element method. Elastic beam method has the advantage of reliable and is practically used in the engineering projects. The finite element method has the clear mechanical concept and has a relatively high accuracy. This paper presents a case history of large deep excavation in Nanchang. Both elastic beam and finite element methods are used in the analyses of the supporting system and the impact of the unsymmetrical loading on the safety of the supporting system is also evaluated. The results indicate that the supporting system used is technically sound and the safety requirements are met. The solider pile deformation controls the ground subsidence. Asymmetric loading has the impact on the deformation on the excavated area and ground subsidence and it has less impact on the stresses in the supporting support system.

Key words: Large Deep Excavation, Elastic Beam Method, Finite Element Method, Unsymmetrical Loading