地铁车辆段不同区域振动特性对比分析

Comparative analysis of environmental vibration characteristics in different regions of a metro depot

基于广州某车辆段的现场实测,分析了列车运行引起试车线、咽喉区、检修线区域的振动特性差异,总结了三类区域振源的衰减规律,并用统计学方法对比各组测试数据的离散特性,最后对车辆段内各区域进行了环境影响评价。研究结果表明:试车线引起地面垂向振动的主要频率为60~80 Hz,咽喉区地面垂向振动主要频率为50~60 Hz,库内检修线地面垂向振动主要频率为20~40 Hz;从各工况Z振级拟合曲线可以得出,试车线列车荷载引起的近地点振源强度最大,咽喉区次之,检修线最小;在咽喉区,相对于采用混凝土轨枕的轨道,采用聚氨酯轨枕的轨道引起地面振动明显增大且衰减较慢,轨道结构及道床应进行减振优化。按照GB 10070-88标准,试车线距振源5 m内的振动超过限值,咽喉区距振源10 m内的振动超过限值,而检修线在2.5 m外区域的振动均满足限值要求。

The environmental vibration characteristics in different regions of a metro depot, such as the testing line area, the throat area and the repairing line were analyzed. The attenuation of the ground vibrations caused by three types of vibration sources were summarized, and the discrete characteristics of different sets of test data were compared by the statistical method. The environmental evaluation for each area in the metro depot was carried out. The results show that the main frequency of the ground vertical vibration in the testing line area is 60—80 Hz, that in the throat area is 50—60 Hz, and that in the repairing line area is 20—40 Hz. From the Z vibration level fitting curve for each working condition, it is found that the strength of the ballast foot vibration caused by train loads in the testing line area is the largest, followed by that in the throat area and that in the repairing line area is the lowest. In the throat area, compared to the track with concrete sleepers, the ground vibration of the track with polyurethane sleepers increases obviously and its attenuation rate is rather slower, consequently, the track structure and ballast bed should be optimized for vibration reduction. According to the criterion GB 10070-88, in the testing line area, the vibration level of the ground at a distance of within 5 m from the vibration source exceeds the limit;in the throat area, the vibration level of the ground at a distance of within 10 m from the vibration source exceeds the limit;in the repairing line area, the vibration level of the ground further than 2.5 m distant from the vibration source meets the limit requirement.