Underground Metro rail excavation involves mining of twin tunnels using tunnel boring machines passing through a diverse geological strata, important buildings, and water bodies. This paper focusses on comparing the evaluated face pressure using theoretical methods with the actual data collected during TBM operation. For this study, the TBM stretch between two metro stations, covering a tunnel length of 1.2 km is considered. This stretch encounters mixed geological conditions comprising silty sand and Grade V rock, with about 300 m passing beneath river. The overburden above the tunnel crown in the river underpass ranges from 14 to 20 m, with a water level of approximately 2 m above riverbed. The paper suggests various methodologies such as COB method, Anagnostou–Kovari method and DAUB method to estimate face pressure for the tunnel stretch beneath the river. Based on estimations, operational range is proposed to mitigate active or passive failure. As the TBM excavation is completed in this stretch, theoretically calculated TBM face pressures are compared with real time excavation data. The operating pressure during the excavation is checked against the recommended range of face pressure. It is found that the variation is reasonable and within the range.