ABSTRACT
Excavation protected by diaphragm walls may be considered as the default execution method for stations and other rail-and underground structures in urban areas. Diaphragm walls of reinforced concrete are built section by section. The principal construction phases of such a section, called panel, are as follows: (a) construction of guide wall (b) panel trench excavation under bentonite slurry or other supporting fluid (c) bottom-up concrete filling of the trench using a tube (d) reinforcement installation. Diaphragm wall panels may reach important dimensions (up to 1.2 m width, 8 m length and 60 m depth are not exceptional).
