Study on Design Control Parameters of Static Long-wave Irregularity of Long-span High-speed Railway Bridge Track
In the current design and acceptance standards for high-speed railways in China,the 300 m baseline and 150 m external distance difference method are used for the long-wave irregularity evaluation of the tracks of high-speed railways(HSR)in China.However,such evaluation methods are inadaptable to the inherent deformation characteristics of long-span bridges,with the dynamic changes of the track alignment with temperature variation and concrete shrinkage and creep.The 60 m midpoint chord measurement method was determined to evaluate the long-wave irregularity of long-span bridge track,via the sensitive wavelength analysis of current high-speed trains in China,coupled with monitoring results during operation period of several long-span HSR bridges and the effective measurement range of different chord lengths.By simulation and measurement methods,the regularity control limits at 250 km/h,300 km/h,and 350 km/h by the 60 m midpoint chord measurement method were obtained.The engineering practice of multiple long-span bridges shows that the 60 m midpoint chord measurement method,with good applicability,can be referred to in the future design and acceptance of long-span HSR bridges.