【摘要】 青藏铁路穿越大片的多年冻土区,其中为防止复杂冻土条件下产生冻土病害而采取了大量"以桥代路"的工程结构形式。为了把握青藏铁路多年冻土区机车振动荷载作用下铁路路基及桥梁桩基的动力响应特征,分别选取了典型路基结构和桥梁桩基结构进行了现场强震动测试。通过现场强震动测试得到了机车通过的实时加速度波形并对测试数据进行了加速度响应及傅里叶谱响应分析,得出铁路不同结构形式的振动响应衰减规律及振动能量的分布规律,同时得到了两种不同结构的固有频率特性。研究结果表明路基和桥梁结构在机车振动的传递方面均具有明显的衰减效应,其测试结果对于青藏铁路稳定性评价具有重要的科学意义。更多还原

【Abstract】 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.更多还原