Performance and analysis of a deep excavation in Lisbon

Abstract

The study of a deep excavation for the construction of five underground floors of a large building in Lisbon is presented. The excavation was supported by a multi-strutted diaphragm wall.  The retaining structure has been instrumented to record the lateral displacements of the wall as well as the loads carried by the struts. The behaviour of the structure was observed from the initial stage of the excavation until the substitution of all the struts by the slabs of the underground floors.  With the help of a finite element model several analyses of the work were performed in different stages of the construction.  The field and analytical results are discussed and compared. Several conclusions are enunciated.