Abstract: As deep soft soil lies under the site of Tiantian green square project of Zhuyeshan station of Wuhan Metro Line 8,special research is required to investigate the influence of large irregular deep foundation pit excavation on the surrounding Beijing-Guangzhou railway,urban viaduct and other important buildings.Based on 3D finite element dynamic numerical simulation of the excavation and support scheme,we proposed some targeted reinforcements for key parts by comparing the numerical result with the allowable deformation in sepcifications.Moreover,we monitored the excavation and support process of the actual project,and found that the deformation of adjacent buildings and structures quickly reached the maximum value and tended to be stable when the foundation pit is excavated to the bottom elevation.Special reinforcement scheme could effectively control the deformation of surrounding key structures,which verified the effectiveness of the excavation and support scheme and in the meantime ensured the smooth construction of deep foundation pit in deep soft soil area.Refined numerical simulation could overcome the limitations of relevant industry specifications in evaluating the interaction between new construction and existing complex projects,and also could provide a necessary technical support for rational optimization of engineering schemes.

Key words: deep soft soil area, large irregular deep foundation pit, adjacent buildiags, 3D finite element, support and reinforcement, deformation control