Characterization of rail wear and wheel-rail contact compatibility in China’s high-speed railway network

China’s high-speed railway (HSR) network, the largest globally in terms of operational mileage, faces significant challenges in maintaining rail quality and wheel-rail contact compatibility due to the demanding requirements for high operating speeds, superior ride comfort, and strict safety standards. This study systematically characterizes rail wear and evaluates wheel-rail contact compatibility across 21 HSR lines based on extensive field measurements of 31,918 rail profiles and four typical wheel profiles. The spatial distribution and consistency between left and right rails are considered during the rail wear analysis. The equivalent conicity and wheel-rail contact bandwidth are evaluated to characterize the compatibility. Results reveal spatial heterogeneity in wear distribution, left-right asymmetry, and notable curvature variations in worn profiles. Wheel-rail contact geometry analysis shows that the nominal equivalent conicity and contact bandwidth of 3 mm are generally lower than baseline values, with worn wheel profiles exacerbating variability. The observed wear patterns and contact characteristics provide data-driven insights for developing rail maintenance strategies aimed at optimizing wheel-rail contact geometry of HSR operations.