Numerical analyses of cross and buttress walls effectiveness

This paper presents the main results of a numerical study aimed to a comparative evaluation of the effectiveness of cross walls (CWs) and buttress walls (BWs) in reducing displacements fields induced by deep excavations. Numerical analyses refer to a deep excavation supported by CWs or BWs; varying spans and geometries of sacrificial walls were considered. The soil profile is constituted by a thick soft clayey soil deposit covered by a top layer of coarse grained made ground and it is typical of the central area of Rome. Soil behavior was modelled using a plasticity hardening model. Both diaphragm and sacrificial walls were modelled with solid elements; thin solid interfaces were also introduced in order to model the soil-wall and wall-wall contacts. The results obtained from numerical analyses allowed to link the amount of reduction of wall movements in presence of sacrificial walls to their main geometry parameters, furnishing guidance for preliminary design.