PurposeIn order to systematically grasp the changes and matching characteristics of wheel and rail profiles of high speed railway (HSR) in China, 172 rail profile measurement points and 384 wheels of 6 high-speed electric motive unites (EMUs) were selected on 6 typical HSR lines, including Beijing–Shanghai, Wuhan–Guangzhou, Harbin–Dalian, Lanzhou–Xinjiang, Guiyang–Guangzhou and Dandong–Dalian for a two-year field test.Design/methodology/approachBased on the measured data, the characteristics of rail and wheel wear were analyzed by mathematical statistics method. The equivalent conicity of wheel and rail matching in a wheel reprofiling cycle was analyzed by using the measured rail profile.FindingsResults showed that when the curve radius of HSR was larger than 2,495 m, the wear rate of straight line and curve rail was almost the same. For the line with annual traffic gross weight less than 11 Mt, the vertical wear of rail was less than 0.01 mm. The wear rate of the rail with the curve radius less than 800 m increased obviously. The wheel tread wear of EMUs on Harbin–Dalian line, Lanzhou–Xinjiang line and Dandong–Dalian line was relatively large, and the average wear rate of tread was about 0.05–0.06 mm·(10,000 km)−1, while that of Beijing–Shanghai line, Wuhan–Guangzhou line and Guiyang–Guangzhou line was about 0.03–0.035 mm·(10,000 km)−1. When the wear range was small, the equivalent conicity increased with the increase of wheel tread wear. When the wear range of wheel was wide, the wheel–rail contact points were evenly distributed, and the equivalent conicity did not increase obviously.Originality/valueThis research proposes the distribution range of the equivalent conicity in one reprofiling cycle of various EMU trains, which provides guidance for the condition-based wheel reprofiling.

Pendent pedestrian path is a new structure form in long-span city bridges to satisfy vehicle passing demand and pedestrian passing demand simultaneously. For such design form, besides the traditional comfort problem caused by pedestrians, the vibration induced by upper passing vehicles and oncoming turbulent wind also cannot be ignored. In this research, the vibration characteristics of the pendent pedestrian path induced by pedestrians, upper vehicles, and turbulent wind are all investigated based on a designed long-span extradosed bridge. The results show that the design of the pedestrian path could satisfy the comfort demands comprehensively regardless of the local magnification effects of pedestrian path vibration. Reducing the spacing of the supported beam is meaningful for suppressing the local vibration effects. The road roughness of the upper pavement has significant effects on the maximum acceleration of pedestrian paths while the influence of the vehicle speed is relatively limited. An approximate quadratic relationship is observed between the buffeting-induced acceleration and the oncoming wind speed. Thus, the pedestrian path should be closed during strong winds.

This paper presents an experimental investigation on the wind-induced vibration of a transmission tower-line system. A discrete stiffness method is applied to design the aero-elastic model on the basis of similarity theory. The dynamic characteristics of the single tower and the tower-line system are identified and the displacement responses at different positions are obtained under a variety of wind speeds. The mean and the RMS of the displacements as well as their spectra are discussed. Moreover, the test results and the codal specifications are compared in terms of the wind-induced vibration coefficient. The first natural frequency of the single tower is slightly larger than that of the tower-line system. But the damping ratio of the former is smaller than that of the latter, especially in the direction normal to the conductors. At the wind attack angle of 90°, the conductors significantly increase the longitudinal and lateral displacement RMS as well as the longitudinal mean displacement. And more complicated forms of vibration are aroused by the conductors, especially in the lateral direction. The wind-induced vibration coefficient show a notable rise at the position of cross arm, which cannot be characterized by Chinese code. Besides, the wind-induced vibration coefficient specified by the code is much smaller than test results thus the codal value seems to be unsafe for the UHV transmission tower.

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