Study on Seismic Alarm Threshold Value for High Speed Train on Bridge Considering Train-Bridge Coupling Effect

摘要

Bridges have covered more than 50 percent of high-speed railroad lines by far in China, it is of great probability that high-speed trains running on bridges when an earthquake occurs which constitutes a direct threat to the running safety of the trains. In order to evaluate the seismic safety of high-speed train on bridge, obtain the seimic alarm threshold of trains with different speed considering train-bridge coupling effect, a train-track coupling model with 31 degrees is established to simulate the track irregularity of the high speed rail, and the rail irregularity condition is studied considering China power spectral density (PSD) of ballastless track irregularities of high-speed railway. A reasonable analysis model of train-bridge coupling system is set up to obtain the dynamic response characteristics of the model under the excitation of typical earthquakes. Considering PSD of ballastless track irregularities of high-speed railway and different train speed, variation laws of the derailment coefficient, wheel unloading rate, and lateral wheel-rail force have been calculated under typical earthquakes. Compared with the limit values in the code, earthquake alarm threshold value of high-speed trains has been preliminarily confirmed. The research findings will be of great significance to improve the reliability of earthquake emergency disposal system in our country.