Numerical Modelling and Experimental Monitoring of a Full-Scale Diaphragm Wall

Abstract

Ground movements due to deep excavation may cause damage or loss of functionality to nearby building, especially in urban areas: embedded diaphragm walls between the new and the existing buildings can be effective in reducing these movements. The paper reports the results of an experimental and numerical study carried on a full-scale anchored piles diaphragm used to supporting deep excavation in urban area devoted to the new Library of the University of Enna “Kore”, Enna (Italy). Two piles, located in the central part of the diaphragm wall, have been instrumented with conventional inclinometer cases and embedded piezoelectric accelerometers. The experimental measurements recorded during the construction and in operation are reported and discussed in detail. Plane strain finite element analyses using the code PLAXIS 2D are presented in which the diaphragm was modelled to evaluate the geotechnical system behavior. It has been observed that this model allows for a satisfactory simulation of the displacement of the wall during the construction phases under a static loading scenario. The results in terms of horizontal displacements obtained by numerical modelling are in good agreement with those derived by measurements. Furthermore, on the basis of measured data, an empirical method has been used to evaluate the surface settlements, whose values guarantee a good safety threshold to the nearby building.