Abstract: This paper presents field observation results of a deep excavation for construction of a metro in Beijing. During construction, the horizontal displacement of the supporting structure, the stress in the steel strut, and the earth pressures on the soldier piles are monitored. From the monitoring results, it is concluded that the horizontal displacements of the soldier piles are very small; the stress in the steel strut is much smaller than the threshold stress of 80% of yield stress of steel. Both the stresses and the earth pressures acting on the soldier piles are within the safety limits. These results could serve as a reference for the design and construction of similar deep excavation supports.

Key words: Deep Excavation, Excavation Support, Field Monitoring