A study of displacements of structures in the vicinity of deep excavation

In the article the aspects concerning the excavation impact and values of displacements of the ground and existing structures in the vicinity of deep excavations are presented. Four cases of excavations in typical Quaternary soils of Warsaw executed in the close proximity to the existing metro tunnels (and station) are described with special emphasis put on the description and analysis of experimental data including in-situ measurements of vertical displacements of existing metro structures. The discussion and conclusions on the displacements of structures (EPB TBM tunnels with segmental lining and cubature metro stations) in the vicinity of excavations depending on their location relative to excavation are presented. Typical ranges of displacements in relation to the depth, distance and type of structures influenced by deep excavations are given. Equation for the prediction of vertical displacements of TBM tunnels in the vicinity of deep excavation is formulated. In addition, the 2D finite element modelling of one of the described example cases is made and presented in detail. The results of FE analysis are compared to the actual experimental monitoring data.