基于不同地基隔震体系的两层三跨地铁地下车站结构抗震性能分析

Seismic performance of two-story and three-span underground subway station structure under different foundation isolation cases

针对两层三跨地铁地下车站结构的地震破坏特征,采用水泥橡胶砂混合土作为地铁地下车站结构周围回填地基隔震层,建立三种不同地基隔震体系的土-隔震层-地下结构静、动力耦合非线性动力相互作用的二维有限元计算模型,分析了不同地基隔震层设置方案对地铁地下车站结构的相对层间位移角、加速度反应、震后残余变形和混凝土地震损伤破坏等地震反应的影响规律。结果表明:在地下车站结构周围地基设置水泥橡胶砂隔震层可以有效地减轻地下车站结构的地震侧向变形,尤其是在四周都采用隔震材料回填时效果最好;总体来看,在车站结构周围采用不同地基隔震的方法均可以有效地减轻地下车站结构的惯性力和混凝土地震损伤程度,提高了结构的整体抗震性能,从经济角度和施工方便出发,建议优先选用在地下车站结构两侧设置地基隔震层。

Aiming atthe earthquake damage characteristics of two-story and three-span underground subway station structure,this paper used cement-rubber-sand mixtures as the backfill seismic isolation layer material around the underground subway station.Two-dimensional finite element model of soil-isolation layer-underground structure static&dynamic coupling nonlinear dynamic interaction was established.And the influence of different foundation isolation cases on the relative inter-story displacement,acceleration response,post-earthquake residual deformation and earthquake damage of the underground subway station structure was analyzed.The results show that the setting of cement-rubber-sand seismic isolation layer around the underground station structure can effectively reduce the lateral seismic deformation of the underground station structure,especially when the seismic isolation material is used to backfill all around the underground structure.From the economic point of view and the convenience of construction,it is recommended that the foundation isolation layer should be infilled only on both sides of the underground subway station structure.