Mitigating Vibration Impact of Proposed Kathmandu Valley Metro through Numerical Modeling

This study aims to evaluate ground vibrations induced by the proposed Kathmandu Metro Train in the soft soils of Kathmandu Valley, addressing the lack of local experimental data. Numerical modeling was performed using Plaxis 3D, with soil properties from Bhimsengola and train dynamics represented via a Winkler foundation model. Moving train loads were applied at sleeper–rail intersections using time-history functions that account for train speed, wheel spacing, and axle load. Key findings indicate that peak vertical surface displacement reaches ~5 mm at 25 m from the track, potentially affecting vibration-sensitive structures as per DIN 4150-3 and BS 7385-2. Parametric analysis showed that softer soils amplify vibrations, whereas stiffer soils reduce them. Practical recommendations include soil improvement and lighter passenger trains (170 kN axle load); for high-speed trains (≥216 km/h), advanced ground improvement or subway systems are advised. These results highlight the importance of dynamic analysis for resilient urban rail design.