列车-轨道-地道桥时变系统振动分析..docVIP

Train Derailment on Bridges and Preventive Measures* ZHOU Zhihui, XIANG Jun ZENG Qingyuan (School of Civil Engineering and Architecture, Central South University, Changsha 410075, Hu’nan, China) Abstract: At present, the safety of moving train on bridge is evaluated by means of the criterion of derailment coefficient Q/P and wheel load reduction rate △P/P0. However, test results indicate that train derailment cannot be well judged with current evaluation criterion for derailment. Compare the derailment properties on lines with those on bridges, it can be seen that the mechanism of train derailment on lines is consistent with that on bridges, which is the loss of the lateral movement stability of the train bridge (or track) system. Therefore, the theory of random energy analysis for train derailment used to analyze derailment on lines can be used to analyze derailment on bridges. Using this theory, four cases of train derailment are calculated, and the calculated results correspond to the actually occurring accidents. By investigating the property of lateral rigidity of the bridges on which derailment ever happened, it can be found that the scarcity of bridge lateral rigidity is a dominant cause resulting in derailment on bridges. The fundamental approach to prevent derailment on bridges is to make the bridge lateral rigidity satisfy the safety requirement of moving train. For the existing bridge on which derailment may happen, reinforcing measures may be taken to increase the bridge lateral rigidity, and for the bridges to be designed and built, the limit value of bridge lateral rigidity may be established, with which derailment can be prevented. Calculated results manifest that these measures to increase the bridge lateral rigidity are effective for derailment prevention. Keywords: derailment; bridge lateral rigidity; preventive measures; energy analysis 1 Introduction With the launch of the speed-up campaign of Chinese railways, the operation speed of the f