中文摘要：

通过引入列车振动荷载函数和混凝土损伤模型,建立考虑隧道底部结构和基岩相互作用的振动响应计算模型,研究列车振动荷载作用下基底状况对铁路隧道底部结构受力状态的影响。研究结果表明：当隧道底部结构与基岩接触良好,没有空洞出现时,底部结构受力较小,列车振动不会引起结构新的损伤;随着隧道底部结构与基岩之间淘空距离的增加,底部结构的动力响应和损伤明显增大,淘空超过一定程度后变化加剧,直至振动破坏,不同淘空方式对应不同的极限条件和破坏形态;同时,基底围岩条件越差,隧道基底变形越大,引起底部结构的受力和损伤程度也越大。

英文摘要：

Based on the numerical simulation of vertical load induced by train vibration and damage constitutive model for concrete,a finite difference model that takes the interaction between tunnel base structure and bedrock into consideration was established to study the influence of the bed situation on the force status of railway tunnel base structure.The results show that the force is small when the base structure and bedrock are in good contact,and the new damage that caused by train vibration will not appear on the structure,the dynamic response and damage of tunnel base structure increases obviously with the increase of foundation void distance;the change intensifies when the void distance is above the critical depth until vibration failure;the distinct types correspond to distinguishable critical condition and failure forms.Meanwhile,the worse the conditions of bedrock,the greater the deformation,force and damage of the base structure are.The results of analysis provide rational parameters to design and maintenance of the base structure in railway tunnel.