Construction measuring and deformation analysis of foundation pit in deep silt soil layer under complicated environment

Construction measuring and deformation analysis of foundation pit in deep silt soil layer under complicated environment

Jianhui Yang Deyi Kong* 

School of Civil Engineering, Fuzhou University. Fuzhou 350018, China

College of business administration, Fujian Jiangxia University, Fuzhou 350108, China

Corresponding Author Email:
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In order to study the deformation law of the underground continuous wall + multi-layer support system of deep foundation pit in Fuzhou soft soil area, the deep foundation pit of the Pan Dun station of Metro Line 6# in Fuzhou soft soil area is used as the engineering research background. The body deformation and the internal force and deformation of the supporting structure and the surrounding surface settlement are dynamically measured and the measuring results are analyzed. The research results show that the horizontal displacement of soil and wall gradually increases with the increase of excavation depth. The maximum displacement occurs about 6m away from the basement, then gradually decreases, and the final deformation curve is “bulging type”. The measured subsurface settlement is a parabolic type of lateral surface settlement. The maximum settlement occurs at 7m away from the foundation pit wall. The maximum settlement is about 0.29Hm, which is 0.3%Hm. The longitudinal surface settlement is roughly linear; the multi-layer support is supported. The supporting axial force in the structural system changes dynamically with the earthwork excavation of each layer, the pouring, installation and removal of adjacent supports. The axial force of the upper and lower layers is obviously smaller than that of the intermediate support. The research results verify the reliability and rationality of the design of the deep foundation pit supporting structure-underground continuous wall + multi-layer support system, and have certain reference for the design and construction of other subway line sites and similar foundation pit projects in Fuzhou area.


deep foundation pit, deep silt layer, monitoring, deformation analysis

1. Introduction
2. Project overview and geological conditions
3. Foundation pit support scheme and construction condition
4. Monitoring level, project and measure point arrangement
5. Monitoring period and monitoring frequency, early warning control value
6. Analysis of monitoring results
7. Conclusions

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