既有250 km/h高速铁路提速的线路技术条件与速度限值研究OA

[Objective]This study aims to identify the controlling factors restricting speed increases on curved sections of existing 250 km/h high-speed railway infrastructure,and to propose upgrading recommendations for speed increase on such infrastructure.[Methods]Based on stochastic vibration and multibody dynamics theories,a vehicle-track coupled dynamics model was established.[Results](1)Under the requirements of current technical standards,the potential for increasing vehicle speed on existing 250 km/h railway infrastructure was limited,and the maximum operating speed of vehicles cannot reach 300 km/h.(2)The maximum design superelevation specified in current standards restricted further vehicle speed increases.Increasing the maximum design superelevation to 200 mm was recommended.(3)The cant deficiency played a decisive role in the vehicle dynamic performance on circular curve sections,and the maximum cant deficiency of 90 mm specified in current standards was relatively stringent.It was recommended that this value be gradually increased to 100~105 mm.(4)Within a certain range of variation,the intermediate circular curve length and rate of change of superelevation had limited effects on vehicle dynamic performance.It was recommended that the minimum intermediate circular curve length be gradually reduced from 0.6V to 0.4V(V represents the design speed),and the maximum rate of change of superelevation be gradually increased from 31 mm/s to 45 mm/s,so that the intermediate circular curve length and transition curve length of existing infrastructure can meet the operating requirements after speed increase.(5)After the track superelevation was adjusted to 200 mm,the maximum operating speeds under the three curve radii of R=2 800,3 200,and 3 500 m can reach 272,288,and 303 km/h,respectively.[Conclusion]The intrinsic interrelationships among plane curve parameters are revealed.The effects of cant deficiency,intermediate circular curve length,and rate of change of superelevation on vehicle dynamic performance are clarified.The speed limits of vehicle operation under different track superelevation conditions are obtained through analysis.The research methods and findings can provide guidance and reference for similar studies.