Abstract: In the construction of a deep excavation project, the nearby subway tunnels, station halls, passages gallery and ventilation structure were monitored during the excavation. Base on the construction monitoring data analysis and evaluation, the following conclusions are obtained: Within the excavation depth between 5 meters and 10 meters, large horizontal deflection was observed the subway tunnel structures but the observed vertical settlement was small. It is suggested the segmental tunnel excavation method should be used, and the strength of the supporting structure or large supporting structure sizes should be used, along with a closer construction monitoring plan with focus on the horizontal deformation monitoring. Within the excavation depth between 10 meters and 16 meters, larger vertical settlement values were monitored at the subway tunnel with a small horizontal deflection. It is suggested that the construction monitoring program should be focused on the vertical settlement monitoring. Supporting structure reinforcement should be applied at larger deformation areas in the subway tunnel.

Key words: deep excavations, subway, deformation, construction monitoring