Rail wear characteristics and key parameters optimization for heavy-haul railway small-radius curves

Severe non-uniform rail wear on small-radius curves poses a critical challenge to the safety and maintenance efficiency of heavy-haul railway operations. To address this, this study establishes a comprehensive simulation framework by coupling a vehicle-track dynamics model with a wheel-rail contact solver and an iterative profile update scheme. The fidelity of the framework is rigorously validated through comparison with field measurements of train and track dynamic responses from a heavy-haul line. Subsequently, the wear characteristics of small-radius curves are investigated using profile-based wear indicators, elucidating the evolution laws of rail degradation across distinct operational stages. Furthermore, to optimize the wheel-rail interface, the sensitivity of rail wear to key track geometry parameters is analyzed. A limit-based consequence-weighted scoring method is then employed to determine the optimal ranges for superelevation and gauge widening on small-radius curves. These optimized parameters effectively balance the wear loss between the inner and outer rails, providing actionable engineering guidance for wear mitigation in heavy-haul corridors.