隧道地震响应振动台实验及动力时程分析

Research on Shaking Table Model Tests and Seismic Time History Analysis for Tunnel

本文主要通过数值模拟和大型振动台模型试验对浅埋隧道在不同围岩类型条件下的地震响应特性进行了研究。结果表明:隧道围岩类型对隧道地震响应特性有明显的影响,围岩越好,其抗震性越好;围岩加速度随着高程的增加有明显的放大效应,围岩越差,加速度放大效应越明显;共轭45°方向为较大内力值分布,而隧道拱顶、拱底和边墙内力值却相对较小,内力量值与隧道围岩类型呈反向变化;振动台模型试验和数值模拟结果有较好的吻合性。以上成果对于合理认识浅埋隧道的地震响应特征具有重要意义,可为类似工程提供借鉴。

By mainly using the numerical simulation for shallow tunnel,this paper made stu dies on the seismic response character in different types of surrounding rock co nditions,while we check the results according to large-shaking table model test.The results indicated that the type of surrounding rock have great effect on t he seismic response character,the better surrounding rock condition are,the mo re excellent the ability of resisting to shock would be.Otherwise,the accelera tion have obviously scale-effect with the elevation increasing,the worse surrou nding rock condition are,the more remarkable scale-effect of acceleration repre sent.Beyond that,the conjugate 45° direction of tunnel have greater internal force value than crown and bottom of arch.Moreover,the internal force value va ry with tunnel′s type in the opposite direction.Beyond that,there is a good a greement between the shaking table model test and numerical simulation.Above re sults which are important to recognize the seismic response character reasonably in shallow tunnel can provide reference for the similar projects.