盾构隧道在地震作用下可发生接头螺栓剪断、管片开裂、管片端部混凝土脱落、大变形及错台等震害,将影响隧道的安全与正常使用,因此,建立合理的分析模型与计算方法来研究隧道可能的震害具有重要的工程防震减灾意义。采用嵌入梁单元模拟接头,厚壳单元模拟管片,无限元作为动力人工边界,同时在管片之间及管片与地层间设置非连续接触关系,更好地模拟了管片厚度方向应力及管片与地层间的相互作用,建立了厚壳-接触-无限元地震响应分析模型。并将该模型运用于某大直径越江盾构隧道的抗震分析中,计算结果与盾构隧道震害特征较为吻合,表明该模型可反映盾构隧道的真实地震动响应。并应用该模型分析了壁后注浆层材料参数及结构与土体相互作用对管片动力响应的影响。所建模型对于研究盾构或TBM施工隧道的震害分析具有很好的推广价值。
Seismic load can bring serious damage to shield tunnel Reasonable seismic analysis of tunnel can help to reduce or avoid potential seismic hazard. So it is necessary to establish efficient model for seismic response of shield tunnel. Segment connectors are simulated by embedded beam elements, and segments are simulated by thick shell elements. At the same time, noncontinuous contact is built between segments and between segment and surrounding soil, which can better simulate stress in thickness direction and the interaction between segments. Thereby, the thick shell-contact-infinite element model for dynamic analysis of shield tunnel is built. Actual seismic disaster data and project results prove that the model has good accuracy. Finally, the model is used to analyze grouting material parameters and contact nonlinearity on the impact of seismic response of segments. This model has a good popularization value for seismic disaster analysis of shield tunnels or tunnels constructed by TBM.