Abstract: This paper presents a case history of construction monitoring of the deep excavation for the ventilation shaft of Shaoxing Metro. The lateral deflections of the supporting structure as well as soil mass, settlement of adjacent soils as well as nearby highway and the axial force in the supporting structure were monitored. The results indicate that, the deflection curves measured in the supporting structures using slope inclinometer are similar to those observed in the adjacent soils and the maximum lateral deflections occurred at the bottom of the excavation. Spatial effect was observed in settlement in the adjacent soils and the bowlshaped settlement pattern was measured at each side. The magnitude of the settlement was not only related to the lateral deflections of the supporting structures, but also was affected by the near be surcharge and the bottom heave of the excavated area. On the adjacent express highway, maximum settlement was measured at locations close to the excavated area, he frequency of the construction monitoring should be increased to ensure that the construction disturbance can be minimized. The axial force in the supporting structure increased rapidly during the initial excavation stage and became stable afterwards.

Key words: Construction Monitoring, Diaphragm Wall, Horizontal Deflections, Settlement