Abstract: A deep excavation using Soil Mixing Wall (SMW) method in Fuzhou City was monitored during the construction. The monitored data included: horizontal displacement and vertical settlement behind and in front of the SMW supporting system; stresses within the internal strut supports and groundwater level. Some of the practical conclusions can be drawn from the monitored data: the magnitude of deep horizontal displacement in the soil mass increases with the excavation depth as well as the density of the internal strut supports. The magnitude of horizontal and vertical deflections at the top of the excavation vary with the same relationship as the deep soil horizontal displacement. A concave shape of settlement curve at the ground surface was observed at the north side of the excavation and a triangular settlement shape was identified at the south side of the excavation. The magnitude of the settlement was also affected by groundwater fluctuations and a lapsed effect was found. The typhoon induced precipitation had a significant impact on the stress in the internal support and the deflection of the supporting system.

Key words: Deep Excavations, Soil Mixing Wall (SMW) Method, Construction Monitoring, Internal Support, Deflections