施工振动下基于黏弹性边界的地下结构动力特性模拟

结合上海市人民广场地铁换乘大厅枢纽工程，建立了基于黏弹性边界的三维有限元分析模型，利用Newmark数值方法对在拆除临时混凝土支撑振动条件下结构的动力特性进行研究，并将数值计算结果与现场监测结果进行比较.结果表明：所建立的基于黏弹性边界的数值模型不仅能够较好地模拟施工振动下结构的动力特性，消除土体与结构交界面的振动波虚假发射；而且可以预测激励荷载下结构发生共振的可能性.

Dynamic Modeling of Underground Structure Based on Viscoelastic Boundaries under Construction Vibration

A three-dimensional finite element model based on viscoelastic boundaries was developed to effectively capture the dynamic behavior of the metro transfer hall hub of the People’s Square.Dynamic characteristics of the underground structure during vibration induced by dismantling temporary reinforced-concrete supporting system were studied,resorting to the Newmark method.In-situ monitoring data were used to calibrate the proposed method in this paper.The results show dynamic characteristics of the underground structure under vibration loading are accurately simulated by the presented model based on viscoelastic boundaries,and thus spurious reflections on the interface of soil and structure can be effectively eliminated.Prediction on the possibility of structural resonance under vibration loading can also be made by the proposed model,which is of benefit to decision making of engineering design and construction.