时速120 km地铁多种减振轨道结构振动特征分析

Analysis on Vibration Characteristics of Various Types of Metro Vibration-reducing Track Structures at Speed of 120 km/h

为研究时速120 km地铁多种减振轨道结构的振动特征及振动传播规律,对比分析了某时速120 km地铁线路上的DZ-Ⅲ型减振扣件轨道、GJ-Ⅲ型减振扣件轨道、减振垫浮置板轨道在时域和频域内的实测结果。时域分析结果表明:3种轨道结构的浮置板(道床板)振动加速度幅值大致相等,减振垫浮置板轨道处隧道振动加速度幅值比其余2种轨道处小一个数量级,更有效地削减了振动加速度幅值。频域分析结果表明:在20~80 Hz和0~20 Hz频段内,减振垫浮置板轨道的隧道振动加速度级比另外2种轨道小,减振效果更好。除GJ-Ⅲ型减振扣件轨道钢轨与道床板间在0~80 Hz频段内衰减不明显外,振动加速度的传播大致遵循由钢轨到浮置板(道床板),再到隧道逐层衰减的规律。

In order to study the vibration characteristics and vibration propagation laws of various types of metro vibration-reducing track structures at speed of 120 km/h,The time-domain and frequency-domain measured results of DZ- Ill vibration-reducing fastener track （ DZ- Ⅲ VRFT） , GJ-Ⅲ vibration-reducing fastener track （ GJ- Ⅲ VRFT） and rubber pad floating slab track（RPFST） were compared and analyzed. The results of time-domain analysis show that the amplitudes of vibration acceleration of the floating slab （ roadbed slab） of the three types of track structures are approximately equal, and the amplitude of tunnel vibration acceleration at RPFST is one order of magnitude smaller than the amplitude of the tunnel vibration acceleration at the other two track structures and RPFST most effectively reduces amplitude of vibration acceleration. The results of frequency-domain analysis show that the tunnel vibration acceleration level of RPFST is smaller and the vibration-reducing effect is better than that of the other two tracks in the frequency range of 20 - 80 Hz and 0 - 20 Hz. Except that attenuation between rail and roadbed slab of G J- Ⅲ VRFT in the 0 - 80 Hz frequency band is not obvious, the propagation of vibration acceleration generally follows the law of attenuating from rail to floating slab （roadbed slab）, and then to tunnel, layer by layer.