Abstract: The construction of the pedestrian underpass beneath the street in the urban area will have unavoidable adverse impact on the adjacent environment. The simulation of the construction procedure has an important role in maintaining a safe construction. The three dimensional numerical model of the construction procedure of a shallow buried pedestrian underpass is developed with MIDAS GTS commercial software. The objectives of the analysis include the settlement at the crest of the tunnel as well as the adjacent ground. The results indicate that the excavation of the upper portion of the tunnel has a larger impact of the ground surface settlement. The immediate erection of the supporting in this area will have a good result in the settlement control. The ground surface settlement induced by the traffic load and settlement at the tunnel crest are the indicators for the safe tunnel construction. It is also concluded that the numerical analysis can provide valuable information in guiding the safe construction.

Key words: Excavation of Shallow Buried Tunnel, Tube Shielding, Stepped Excavation, Numerical Simulations