The Merksem Viaduct, part of Antwerp's R1, was built between 1965 and 1969 and has been in use since 1970. It consists of over 40 spans with varying heights. As part of the Oosterweel project, a new tunnel will be constructed next to the northeastern viaduct, requiring the demolition of the southwestern viaduct and excavation near the northeastern viaduct. This excavation causes horizontal and vertical displacements, adding forces to the substructure. The viaduct remains in use during this process, posing structural safety challenges. A parametric FEM-model with beam elements is used to calculate the effects of these displacements, with input parameters derived from 2D and 3D phased nonlinear soil analyses in Plaxis. This approach provides a fast and effective method to assess the impact of settlements on the substructure with many piers.
Dam et al. (Wed,) studied this question.