列车制动下长大坡道无缝线路纵向力学性能研究OA

In service,continuous welded rails(CWR)on long and steep gradients are subjected to train braking and other effects,presenting a complex stress deformation state along longitudinal direction the track.Based on theoretical analysis,this paper derives the calculation formulas for rail braking force and longitudinal displacement of CWR on ballasted tracks of long and steep gradients under train braking.The influences of track gradient,ballast longitudinal resistance,train formation,axle load and wheel-rail adhe-sion coefficient are comparatively analyzed.The results show that with the increase of track gradient and wheel-rail adhesion coefficient,the peak valuse of compressive and tensile forces of rail braking force as well as the maximum value of longitudinal displacement of CWR increase linearly during train braking.As the ballast longitudinal resistance rises,the above peak values exhibit a power-law attenuation character-istic.For different train formation,the peak braking force and maximum longitudinal displacement of CWR re-main nearly constant once the train traction load reaches a critical value.For locomotive and vehicle combina-tions with different axle loads,the braking force and longitudinal displacement of CWR under train braking are comprehensively determined by axle load,axle number,and vehicle length and locomotive length.The influence of train braking on the areas ahead of the first wheel and behind the last wheel is remarkably sensitive to bal-last longitudinal resistance.The smaller the ballast longitudinal resistance,the wider the influencing range.