无缝换乘地铁车站的地震响应特性研究

为探究无缝换乘地铁车站的地震响应特性,提高对此类车站结构抗震性能的认识,首先开展此类车站结构缩尺模型的振动台试验.试验方案设计包括试验模型的制备、试验测点的布设与采集、试验加载工况设计;随后对模型试验过程进行三维有限元数值模拟.通过对比数值模拟与实测结果,分析模型土的加速度响应规律、结构模型的应变和内力响应规律以及侧墙上的土压力响应规律.结果表明:数值结果与实测结果吻合较好,验证了本文建模方法的合理性;对于无缝换乘地铁车站结构模型,车站交叉端部对车站结构构件的变形、内力以及周围土层影响明显,而当与车站交叉端部的距离超过1.5倍的车站结构宽度以后,影响基本消失.上述结论可为复杂地铁车站地震分析的三维计算方法以及此类型车站结构的抗震设计提供有力支持.

Study on Seismic Response Characteristics of a Seamless Exchange Subway Station

To study the seismic response characteristics of the seamless transfer subway station and improve the understanding of the seismic performances of such station structures, the shaking table test on a scale model of such station structure was carried out for the first time. The design of the shaking table test included the preparation of test models, the arrangement of measuring points, collection of testing data and the design of test working conditions. Then, the processes of the model test were simulated by three-dimensional finite element method. Through comparison between the numerical and measured results, acceleration responses of the model soil, strain and internal force responses of the structure model and soil pressure responses on the sidewall were analyzed. The results showed that the numerical results agreed well with the test data, which validated the rationality of the modeling method in this paper. For the structure model of the seamless exchange subway station, the structural exchange end had an obvious influence on the structural deformation, the structural internal force and its surrounding soils. When the distance between the station exchange ends exceeded 1.5 times station structural width, its effect basically disappeared. These conclusions can provide powerful support to the three-dimensional calculation method for the seismic analysis of complex subway stations and the anti-seismic design of such station structures.