中文摘要：

文章基于动力有限元理论，采用激振函数模拟列车荷载，建立了重载铁路隧道结构与围岩的耦合数值计算模型，分别分析了不同矢跨比、填充层厚度和仰拱厚度对重载铁路隧道底部结构动力响应特性的影响。结果表明：重载作用下，隧道底部结构各部位的动力响应程度较常规铁路隧道更大，对结构的稳定性更为不利。同时通过研究得出了重载作用下，隧底结构不同力学指标的最大响应值及其出现的具体位置，进一步通过设置典型参数丁况，探讨了重载双线铁路隧道底部结构的合理设计参数，对于重载双线铁路隧道底部结构，矢跨比、填充层厚度、仰拱厚度分别取为1／10．1／11、1．2～1.3m和40．50cm较为合理，能有效改善重载双线铁路隧道底部结构的动力响应及受力状态。

英文摘要：

A numerical model coupling a heavy-haul railway tunnel structure and its surrounding rock is estab- lished using the excitation function and based on the theory of dynamic finite element. The influence of different rise-span ratios and the thicknesses of the filling layer and invert on the characteristics of the dynamic response in a heavy-haul railway tunnel structure are analyzed. The resuhs show that dynamic response of the whole floor struc- ture of a heavy-haul railway tunnel is larger than that of normal railway tunnel and it is unfavorable for the stability of tunnel structure. The maximum response values of different mechanical indexes for a tunnel floor structure under heavy load and corresponding positions are obtained. Reasonable design parameters for the floor structure of a dou- ble-track railway tunnel under a heavy load are discussed; for the floor structure of a heavy-haul double-track rail- way tunnel, a reasonable rise-span ratio and thickness of the filling layer and invert are 1/10-1/11, 1.2-1.3 m and 40-50 cm, respectively. These parameters could effectively improve the dynamic response and stress state of these structures.