地铁下穿古建筑地段装配式无砟轨道振动特性

Vibration Characteristics of Prefabricated Ballastless Tracks for Metro Lines Crossing beneath Ancient Buildings

随着城市轨道交通的高速发展,环境振动问题日益严重,特别是对于古建筑保护地段,振动不可避免地对古建筑产生影响,目前尚缺乏快速城市轨道交通对古建筑的影响研究。基于耦合动力学模型,对比分析古建筑地段一般道床、高等减振道床的振动特性,结果表明:(1)高等减振道床有效降低了古建筑的振动,垂向振动速度减少28%,横向振动速度减少32.3%;(2)高等减振道床对隧道壁的减振效果可达11.29 dB,土体的减振效果达10.78 dB;(3)横向距离振源10~20 m位置为振动不利位置,应避免此处存在敏感地段;(4)列车运行速度对古建筑的振动有较大影响,当列车速度降至80 km/h时,古建筑的振动速度大幅降低,且减振效果最佳。

With the rapid development of urban rail transit,environmental vibration is becoming a growing problem.Especially for ancient building protected sections,vibration inevitably affects ancient buildings.At present,there is still a lack of research on the impact of rapid urban rail transit on ancient buildings.Based on the coupled dynamics model,this paper compares and analyses the vibration characteristics of general track beds and high-grade vibration reduction track beds in ancient building sections.The results show that:(1)The high-grade vibration reduction track beds effectively reduce the vibration of ancient buildings,with vertical vibration speed reduced by 28%and lateral vibration speed reduced by 32.3%;(2)The vibration reduction effect of high-grade vibration reduction track beds on tunnel walls can reach 11.29 dB,and that of soil mass can reach 10.78 dB;(3)The place 10~20 m away from the vibration source in horizontal direction is considered an unfavorable vibration zone,and sensitive areas shall be avoided here;(4)The train speed has a great influence on the vibration of ancient buildings.When the train speed is reduced to 80 km/h,the vibration velocity of ancient buildings decreases greatly with the best vibration reduction effect.