Impact of Alignment Parameters on Train Dynamics and Structure Vibration in Curved Floating Slab Tracks

This study focuses on urban railway train parameters and train speeds up to 120 km/h, which examines how curve alignment parameters affect train dynamic responses and structural vibrations in curved floating slab tracks, combining theoretical analysis with simulation, translating nonlinear physical mechanisms into computable engineering formulas. A coupled train–track dynamic simulation model and an environmental vibration simulation model are established. Key findings show that vertical loads on inner rail fasteners increase with higher unbalanced superelevation, while those on outer rail fasteners decrease. Lateral loads and resultant lateral/vertical loads on fasteners rise linearly with the absolute value of unbalanced superelevation. The peak frequency of fastener loads under unbalanced superelevation primarily falls within the ranges of 1.6–2.5 and 3.15–10 Hz. In contrast, straight sections or sections with balanced superelevation exhibit nearly linear load spectra. Compared to straight sections, curved sections show increases of up to 210% in peak fastener loads. The peak values of fastener loads, wheel–rail contact forces, vehicle accelerations, derailment coefficients, and wheel load reduction rates are mainly influenced by train speed, curve radius, and superelevation. Rail and slab displacements are additionally affected by spring stiffness. Fitting formulas derived for these variables provide a theoretical basis for optimizing the relationship among curve radius, train speed, superelevation, and steel‐spring stiffness, with the aim of improving both driving safety and vibration mitigation in railway systems. The peak vertical vibration acceleration of floor slabs generally increases with floor height, while peak lateral vibration acceleration shows no significant variation. Under balanced superelevation conditions, lateral acceleration spectra exceed those under straight‐track conditions, with notable differences in spectral shapes across floor levels. These results offer a theoretical foundation for optimizing track geometry and structural parameters in floating slab track systems, as well as a framework for predicting and assessing driving safety and structural vibration performance.