客、货列车通过既有线路曲线段的振动响应测试分析

Test and Analysis of Vibration Response Induced by Passenger and Freight Trains Passing Curved Track Section of Existing Line

为研究客、货列车通过既有线路曲线段时引起的轨道及自由场地地表的振动特性,在京哈线某圆曲线路段进行现场振动测试。结果表明:坡脚的振动响应明显低于轨枕振动响应,表明振动能量在道砟中明显衰减;客车通过时,各车辆引起的轨道系统垂向振动加速度较为均匀,货车通过时,由于编组内各车辆装载的货物重量不一致而导致轨道系统垂向振动加速度差异较大,其中钢轨振动加速度峰值的差异甚至超过900m·s^(-2);在10Hz以下低频段内,货车通过时引起的轨道和自由场地振动响应大于客车通过时的;客、货列车通过时引起的自由场地Z振级虽然相差不大,但二者的暴露振级差别明显,说明暴露振级这一评价指标能够更真实地反映客、货列车通过时二者在列车荷载作用时间及所产生振动能量方面的差异性,因此在评价货车对环境振动的影响时应综合采用Z振级及暴露振级这2个评价指标。

In order to study the vibration characteristics of track system and nearby ground vibration induced by passenger and freight trains passing the curved section of existing line,in-situ vibration tests were conducted in a circular curve section of Beijing-Harbin Railway.The results showed that the vibration response on the toe of slope was obviously lower than that of sleeper,which indicated that the vibration energy was markedly attenuated in ballast.The vertical vibration acceleration of track system induced by each wagon was more uniform when passenger train passing.However,when freight train passing,the difference was greater in the vertical vibration acceleration of track system due to the different cargo weight of each wagon in train formation.The difference in the peak value of rail vibration acceleration was even more than 900m·s-2.In the low frequency range of below 10 Hz,the vibration response of track system and nearby ground induced by freight train passing was greater than that induced by passenger train.Although the values of Z vibration level at nearby ground induced by freight and passenger trains passing had little difference,their vibration exposure levels（VEL）were obviously different.This showed that VEL could reflect more realistically the differences in train load duration and the produced vibration energy when both the freight and passenger trains passing.Therefore,Z vibration level and VEL should be both adopted for evaluating the influence of freight train on environmental vibration.