3D numerical back-analysis of measured strains in a segmental tunnel lining during construction

The paper discusses the monitoring data obtained by long-term monitoring of the strains in the instrumented segments of a precast segmental lining of Metro Line 6 of Naples. Lining strains have been measured by means of vibrating wire gauges embedded in the concrete segments. Back- analysis has been carried out by numerical modelling taking into account the key factors influencing the lining loads. In addition to the comparison between measured and calculated strains, the results are presented in terms of structural forces, showing the effect of the construction process on the calculated internal forces.