3D modelling of a complex soil-structure interaction between a new motorway artificial tunnel and an existing underground hydraulic channel

Three-dimensional (3D) numerical modelling is an essential tool for analyzing complex geotechnical problems involving soil-structure interaction. In this study, a 3D numerical model was developed to assess the design and construction of a new artificial tunnel required for the upgrade of an existing motorway. The proposed tunnel crosses above an old underground hydraulic channel used to divert a river, creating a critical interaction between the new and existing infrastructure. The model incorporates detailed geotechnical and structural characteristics, as well as the sequential construction and operational phases. Special attention was given to reproducing the construction process realistically to evaluate its effects on the surrounding ground and structures. The results of the analysis enabled the identification of optimal technological solutions to ensure the stability of the new artificial tunnel and to safeguard the structural integrity of the underlying hydraulic channel.