Abstract: A deep excavation is required adjacent to a highlevel protected electricity utility tunnel in soft soils of Ningbo City. The excavation adopts the scheme of partition construction to control the influence of foundation pit deformation. By using MIDAS GTS NX, a 3D model of excavation adjacent the electricity utility tunnel was established by using the staged analytical model of excavation. The deformation results in supporting piles, surrounding soils as well as in the electricity utility tunnel during various stages of excavation were obtained. Compared with the measured results, it is concluded that zoned construction technique could help reducing the deformations in the deep excavations in soft soils. The HSM soil constitutive model was used to in the analysis to accurately reflect the stressstrain relationship of soft soils. The deformation effects of excavation on adjacent electricity utility tunnel were consistent with the monitored data.

Key words: Soft Soils, Deep Excavations, Zoned Construction, Electricity Utility Tunnel, Numerical Simulations, Construction Monitoring