Characteristics of load transmission of trains in permafrost regions along Qinghai-Tibet railroad

The dry bridge, named bridge instead of embankment, has been widely adopted in regions with high temperature and instable permafrost or those with high ice content permafrost along the Qinghai-Tibet railroad. In order to obtain the dynamic response characteristics of typical embankments and dry bridges under the effect of vibration loads of trains in permafrost regions, strong motion tests on the filld embankment at the Beilu River segment and the bridge pile foundation of the Qingshui river Bridge in permafrost regions are carried out. The acceleration waveforms under running of freight and passenger trains are acquired from the tests, and the attenuation laws of vibration response, energy of vibration response and natural frequency are obtained by analyzing the acceleration response and FFT spectrum response. The test results show that there is an obvious damping effect during the transfer process. This study is of great significance to the stability analysis and prediction of the Qinghai-Tibet railroad.