Abstract: This paper presents a case history of analyzing a sudden excessive deformation of the soldier piles of a deep excavation support project within the first terrace of Yangtze River in Wuhan. Throughout an emergency reinforcement project, the importance of implementing the design conditions during the deep excavation supporting system construction is demonstrated in the paper. When the excessive deformation occurred, it is necessary to analysis the deformation and stress characteristics in the original support system as well as the monitoring data. It is also important to find out the reasons that resulting in the support structure failure, to analyze the condition of the soldier piles after the support structure undergone the stress deformation, and to develop feasible reinforcement measures based on site conditions. These timely measures prevented further deterioration of the failure, and the full-process monitoring data analysis fully validated the rationality and the effectiveness of the emergency remediation plan. This case study fully demonstrates the necessity of the implementing of design conditions and has important significance for improving the construction management of deep excavation projects. It also provides a reference for preventing similar accidents in the future.

Key words: Soft Soils, Deep Excavation, Steel Rakers, Emergency Reinforcement, Numerical Analysis