简谐点荷载下饱和土中浮置板轨道隧道的动力响应研究

摘要

Assuming the tunnel liner as Flügge thin cylindrical shell and the soil as saturated porous medium,the dynamic response of the tunnel-saturated soil system under non-axisymmetrical harmonic point load is calculated by decomposing the load and dynamic response along ring modes circumferentially and using Fourier transformation. O n this base,the dynamic response of single beam-tunnel-saturated soil system and double beam-tunnel-saturated soil system under point load is calculated by taking the f loating slab and rail as infinite long Euler beam and considering the interaction among the rail,slab,tunnel-saturated soil system. The research results showed that the load frequency has a great effect on the dynamic response of floating slab tunnel in saturated soil,the floating slab has obvious damping effect,the influence of upper spring and rail in double beam-tunnel-saturated soil system can be ignored in the low frequency range.%假定隧道衬砌为Flügge薄壁圆柱壳，土体为饱和多孔介质，通过把荷载、动力响应沿环向模态分解，利用傅里叶积分变换求得非轴对称简谐点荷载作用下的隧道—饱和土体系统的动力响应。在此基础上，将浮置板、钢轨作为无限长的 Euler梁，考虑钢轨、浮置板、隧道—饱和土体系统的相互作用，求解了单层梁—隧道—饱和土体系统和双层梁—隧道—饱和土体系统在点荷载作用下的动力响应。研究结果表明：荷载频率对饱和土体中浮置板隧道的动力响应有较大影响；浮置板具有明显减振作用；在低频范围内，双层梁—隧道—饱和土体系统中上层的支承弹簧、钢轨的作用可以忽略。