在饱和土体地区,由于流-固耦合效应,实际轨道交通荷载作用下隧道系统动力响应的研究较少,为此提出一种新方法来研究非轴对称简谐点荷载作用下饱和土体中圆形隧道系统的动力响应。假定衬砌为Flügge薄壁圆柱壳,土体为饱和多孔介质,将荷载、动力响应沿环向模态展成级数形式,利用傅里叶积分变换首先求得衬砌-饱和土体系统的动力响应。在此基础上,将道床板作为无限长的Euler梁,考虑道床板、衬砌、饱和土体的相互作用,进一步求解无砟轨道道床板-衬砌-饱和土体系统在点荷载作用下的响应。研究的结果表明这种方法可有效求解非轴对称荷载作用下饱和土中2种隧道系统的动力响应;荷载频率对饱和土中2种隧道系统的动力响应均有较大影响;道床板能减小衬砌、饱和土体的动力响应。
Because of the fluid-solid coupling effect in water-rich region,research about the dynamic response of tunnel system under actual rail traffic load was not done much.A new method was proposed to study the dynamic response of the circular tunnel systems in saturated soil due to non-axisymmetrically harmonic point load.The liner was modelled as Flügge thin cylindrical shell and soil considered as saturated porous medium.Load and dynamic response were expanded into series form along ring modes circumferentially.Dynamic response of the tunnel-saturated soil system was firstly presented by using Fourier transformation.On this base,we modelled the track slab as an infinitely long Euler beam.The interaction between the slab and tunnel-saturated soil system was also taken into account.We also calculated the response of ballastess track slabtunnel-saturated soil system.The research results showed this method could effectively achieve the response of two tunnel systems in saturated soil under non-axisymmetric load.The load frequency had much effect on the dynamic response of both tunnel systems.The slab reduced the response of liner and soil.