地铁浮置板轨道过渡段参数对隧道和土体振动的影响

Effect of Floating Slab Track Transition Section Parameters on Dynamic Responses of Subway Tunnel-Soil System

摘要:

为研究地铁车辆通过浮置板轨道过渡段时隧道和土体的动力响应规律，提出了时域高效计算的隧道-饱和土体半解析环状层单元，结合车辆-轨道动力学，建立了车辆-浮置板轨道过渡段-隧道-土体系统耦合动力计算方法，研究了浮置板轨道过渡段长度、钢弹簧刚度等参数对隧道振动加速度、土体正应力和孔隙水压力的影响。结果表明，过渡段参数设计需重点关注2个刚度突变位置的动力响应，采用钢弹簧刚度渐变方案时，3个动力响应指标分别降低60%、15%和25%。

关键词:地铁隧道;浮置板过渡段;饱和土;环状层单元

Abstract:

To study the dynamic response of the tunnel and soil when the subway train passes the transition section of the floating slab track， this paper proposed a semi-analytical ring layered element for the efficient calculation of the tunnel-saturated soil vibration in time domain. Taking into consideration of the train-track model， the coupled dynamic model of the train-floating slab track transition section-tunnel-soil system was finally established. The effects of the parameters of the floating slab transition section （i.e.， the length and the stiffness of the steel spring） on the tunnel acceleration， soil normal stress and pore water pressure were studied. The results show that the parameter design of the floating slab track transition section needs to focus the dynamic responses at the two positions of sudden changes in stiffness of the transition section. The scheme of the gradient in steel spring stiffness can reduce the three evaluation indexes of the dynamic response by 60%， 15% and 25% respectively.

Key words:subway tunnel;floating slab track transition section;saturated soil;ring layered element