Subway tunnels displacement analysis due to two different communication channels construction procedures.

Due to congestion in overground space, many underground structures have been built to facilitate communications between cities. These structures constructions will induce soil displacement, cities planning rearrangement, and sometimes are near to future buildings constructions. In some cases, communication channels should be built to allow the underground junction between the building and the subway station. Numerical simulation has been carried out to study the tunnel displacement behavior during construction stages. Two different procedures of the communication channel construction were also investigated. The results reliability were evaluated by monitoring six points displacement in the sheet pile walls after completion of the foundation pit. The results obtained were reasonably close to the monitoring results proven reasonably of the research ideas and the method scientificity. The results showed using sheet piles walls, and struts before soil excavation could reduce considerably the lateral displacement of the subway line during the excavation process and induce augmentation in the subway line vertical displacement. The lateral displacement effect of the walls thickness variation is much superior to the one provides by the struts cross-section and pile's diameter variations.