不同加固方式下的软硬过渡段隧道基底受列车动载影响规律

在高速铁路列车动载作用下，隧道穿越软硬岩过渡段时易使隧道结构发生损害，而对于此类工程的动力研究及相关减隔振措施还鲜有涉及。鉴于此，依托广湛铁路相思山隧道工程实例，采用数值计算方法，对比分析无加固以及不同桩板结构加固下隧道穿越软硬岩过渡段时结构的动力响应特性。研究结果表明：在列车荷载作用下，位于交界面软岩侧隧道结构的加速度、动位移和动应力响应与硬岩侧隧道结构的动力响应差异很大，导致隧道交界面附近过渡效果较差，不利于结构的稳定。经三种不同桩板结构加固后，软岩段的隧道结构的动力响应有所减小，且与硬岩段隧道结构的动力响应更接近，过渡效果十分显著。在对比之下，桩板结构1(即承载板+托板+钻孔桩)的减振作用与过渡效果最佳。

The Influence Law of the Tunnel Foundation Subjected to Dynamic Train Load under Different Reinforcement Methods in Soft-hard Transition Section

Under the dynamic load of high-speed railway trains, the tunnel structure is easily damaged when it passes through the transition section of hard-soft rock, while the dynamic research and related vibration reduction measures of such kind of engineering are rarely involved yet. Therefore, in this paper, based on the engineering case of Xiangsishan Tunnel project of Guangzhou-Zhanjiang Railway, numerical calculation method is adopted to compare and analyze the dynamic response characteristics of the tunnel structure passing through the hard-rock transition section without reinforcement and with different pile-plate reinforcement. The research results show that under the action of train load, the acceleration, dynamic displacement and dynamic stress response of the tunnel structure located around the interface of soft rock are very different from that of the hard rock, resulting in poor transition effect near the tunnel interface, which is not conducive to the stability of the structure. After the reinforcement of three different pile-plate structures, the dynamic response of the tunnel structure in the soft rock side decreases and is closer to that of the tunnel structure in the hard rock section, and the transition effect is very significant. In contrast, pile-plate structure 1 (namely, bearing plate + supporting plate + bored pile) has the best damping and transition effect.