水平及竖向地震共同作用下双线隧道的响应分析

Response Analysis of Twin Tunnels Under Horizontal and Vertical Earthquake Loading

基于有效的土-结相互作用有限元数值模拟方法,利用有限元软件ABAQUS对水平及竖向地震共同作用下双线盾构隧道的地震响应进行分析研究。地震动输入选取近场地震Loma、ChiChi、Mammoth和WoLong的基岩水平及竖向加速度时程记录。结果表明,不同近场地震记录对隧道结构的作用不同,隧道的地震反应与场地性质及地震动的频谱特性密切相关。对比隧道在水平及竖向地震动共同作用下的响应与单向水平地震动作用下的响应,发现隧道的最大地震附加内力及其分布均发生较大的变化,在隧道结构抗震设计中需引起重视。另外,分析中还考虑了在双向地震动共同作用下,隧道间距、土-结接触面的摩擦系数、土-结相对刚度、输入的地震记录和竖向地震动相对强度对隧道地震响应的影响等,研究结果对隧道工程的抗震设计具有一定的参考价值。

Based on an effective Finite Element procedure for soil-structure interaction,the seismic response of twin tunnels under combined horizontal and vertical earthquake loading were analyzed by using the ABAQUS package.The horizontal and vertical acceleration time history records at bedrock from the near-field earthquakes of Loma,ChiChi,Mammoth and WoLong were selected as the input ground motions.The results showed that the seismic responses of the tunnels were different as the input earthquake records changed,and the seismic responses of the tunnels were related to the field properties and the vibration frequency characteristics of the input ground motions.By comparing the seismic responses under bi-directional and unidirectional earthquake loadings,it was found that both the distributions and the magnitudes of the seismic additional internal forces were changed greatly,which should be taken into account in the seismic design of tunnels.In addition,parametric studies were carried out on the effects of the space between two tunnels,friction coefficient of contact surface between soil and tunnels,relative stiffness of the soil-structure system,input earthquake motion and relative intensity of vertical earthquake motion.The results may provide a good reference for the seismic design of tunnels.