Numerical model calibration and validation of mechanized tunnel excavation of Milan underground line 5

During the design phase of tunnel constructions in urban areas, advanced finite element models are a convenient tool to predict and reduce the impact of settlement on the surface infrastructure. These models can only deliver realistic results if, on the one hand, the level of detail of the model is high enough and, on the other hand, the model parameters have been well calibrated. Since soils are subjected to large parameter uncertainties, the determination of the model parameters is quite challenging. Therefore, measurement data, which is continuously recorded during tunnel construction, is helpful for calibration. However, at first only assumptions can be made to determine the suitable data for model validation. To make this assumption, a global sensitivity analysis is applied to determine the dominant model parameters. Thereafter, in situ measurements of a residence building that is underpassed by the twin-tunnel excavation of the Milan underground line 5 is used for back analyzes. Finally, suggestions are made on further improvement of numerical model.