Impact of Bored Pile Construction on Deformation of Adjacent Operating Tunnel

Pile foundation construction leads to surrounding strata displacement and adjacent tunnel structural deformation. Based on Nanjing Longjin Bridge Reconstruction Project, field monitoring was used to analyze the impact of various operating conditions on the strata displacement and structural deformation of adjacent tunnel during the bored pile construction. The results show that the maximum strata displacement and tunnel structural deformation are small during the construction of bored pile due to the effect of steel casing, which indicates that the technologies such as removing the soil while spinning steel casing and interval construction have little influence on the disturbance of surrounding soil. It is suggested that the construction method of full casing cast-in-place pile should be adopted in the near-tunnel pile foundation project. The monitoring and analysis results can provide technical reference for similar projects.