Effectiveness of Buttress Walls on Reducing the Wall Displacement for Deep Excavations Adjacent to Metro Tunnels

Buttress wall is a very new construction technique in Vietnam. With a special location, where one side is adjacent to Metro tunnel at a very small distance of approximately 4.2 m, NEXUS high-rise building is the first construction in Vietnam that has to utilize this new technology of retaining wall. In this paper, finite element analysis via PLAXIS software is used to study the actual basement excavations and obtain the structural displacements. Series of numerical simulations were conducted to evaluate the performance of buttress wall under different conditions. Actually, the basement excavation has resulted in a small displacement of the nearby tunnels, which implies that buttress wall indeed has a significant impact and has effectively prevented nearby metro tunnels from displacement. Based on the findings of this study, it is implied that buttress wall can be used as a reliable, sustainable and effective solution for deep excavations in some special civil engineering projects.