Assessing the Impact of a Railway Tunnel on Groundwater Flow Regime in Urban Areas: A Case Study of Bratislava's TEN-T Track and Proposed Mitigation Measures

The Bratislava region in Slovakia aims to improve its transport infrastructure by connecting the airport with the railway network. As part of the Trans-European Network for Transport project (TEN-T), an underground railway line is proposed to be constructed on both sides of the Danube River, connecting the airport in Bratislava to the Petrzalka region on the river's right side. However, underground construction is likely to have an impact on the groundwater flow regime. This construction, which will be built below the ground surface, should be built by excavating from above under the protection of sealing walls to prevent significant changes to the groundwater level regime (GWL). Therefore, a numerical model based on the finite element method (FEM) was established to evaluate the effect of the planned underground construction on the GWL, and technical measures were introduced to mitigate any potential impacts. The results of the model revealed possibilities for controlling the groundwater level in the aquifer affected by the railway structure during and after the construction.