Three-dimensional Stability Analysis of Underground Box Structure in Urban Railway Adjacent to Deep Excavation in the Ground

Since a lot of people live in urban areas with high population in limited small area, railway structures in underground have been constructed mainly in big cities. Urban railway structures are facing high risks by mobilized stresses of soils induced by newly constructed structures on the ground and/or excavations. In recent days, the construction of deep excavation in soils for high-rise buildings has frequently caused the stability problems of underground structures in urban railway. In this study, a three- dimensional finite difference model using the commercial program FLAC3D is adopted to estimate the stability of urban box structures. Soil profiles and properties in the 00 area of Daejeon subway line No.1 is used to model an underground box structure of urban railway adjacent to deep excavation. Displacements and stresses of the structure induced by deep excavations are estimated to examine its stability with respect to the number of struts and various excavation depths and lengths.