Effects from diaphragm wall installation to surrounding soil and adjacent buildings

Abstract

A new approach for simulating the excavation and construction of subsequent panels is proposed to investigate the effects from the installation of diaphragm walls on the surrounding and adjacent buildings. The method has been combined with a 3-D nonlinear analysis and a constitutive law providing bulk and shear modulus variation, depending on the stress path (loading, unloading, reloading). From the application of the method in a normally to slightly over-consolidated clayey soil it was found that the panel length is the most affecting factor of ground movements and lateral stress reduction during panel installation. Moreover, from the evaluation of horizontal stress reduction and the variation of horizontal displacements arises that the effects from the construction of a panel are mainly limited to a zone within a distance of the order of the panel length. The effects on an adjacent building have also been investigated by applying a full soil–structure interaction including the whole building. Settlement profiles and settlements are given at specific points as increasing with subsequent installation of panels, providing the ability of specific monitoring guidelines for the upcoming construction of the diaphragm wall in front of the building. Contrary to lateral movements, which mostly take place at the panel under construction, it was found that the effect of settlements covers a larger area leading to a progressive settlement increase. The effect highly depends on the distance from the panel under construction.