地铁减振板式轨道动力测试与减振特性研究

地铁减振板式轨道作为一种新型轨道结构,具有质量高、施工快、维修少等特点,在地铁线路中逐渐得到推广应用。为揭示地铁板式轨道减振效果,选取天津地铁5号线板式轨道、现浇整体道床断面,采用现场试验和数值模拟方法,对其动力学行为和减振特性进行研究。结果表明:与现浇整体道床相比,地铁板式轨道降低了轮轨横、垂向力和安全性指标,有利于行车安全;由于板式轨道整体刚度较低,钢轨垂向位移略有增加;板式轨道与整体道床结构振动由上至下依次减小,且板式轨道减小幅度更为显著;与现浇整体道床相比,除轨道板振动加速度增大外,其余结构加速度均一定程度减小;板式轨道隧道壁处时域上减振明显,频域上全频段减振,最高减振达16.92 dB。

Dynamic Tests and Vibration Reduction Characteristics of Vibration Damping Slab Track in Subway

The vibration damping slab track, as a new type of track structure, has the characteristics of high quality, fast construction and less maintenance, and is applied extensively in subway lines. In order to reveal the vibration reduction effect of subway slab track, field tests and numerical simulation method are employed on the vibration damping slab track and the common ballastless track of Tianjin Subway Line 5 for studying the dynamic indexes and damping characteristics. Results show that the subway vibration damping slab track reduces the wheel-rail lateral and vertical forces and safety index, which is beneficial to the safety of the train operation compared with the common ballastless track. As the overall stiffness of the slab track decreases, the rail vertical displacement increases slightly. The vibrations of the slab track and the common ballastless track decrease from top to bottom in turn, and the decrease of the slab track vibration is more remarkable. Except for the increase of vibration acceleration of the track slab, the accelerations of all other structures are reduced to some extend. The vibration reduction effect is obvious at the tunnel wall of the slab track in time domain. Vibration reduction works in full frequency domain and reaches up to 16.92 dB.