基于柱顶隔震的3层3跨地铁地下车站结构抗震性能研究

针对3层3跨框架式地铁地下车站结构抗震薄弱构件，采用在柱顶不同位置设置铅芯橡胶隔震支座的方法，建立土-地下连续墙-主体结构非线性静动力耦合相互作用的二维整体时域有限元分析模型，分析柱顶隔震支座对车站主体结构的侧向变形、地震损伤和动应力反应等结构地震反应特性的影响。结果表明，仅在抗震薄弱的顶层和底层中柱柱顶设置2层隔震支座与各层中柱柱顶设置3层隔震支座均可有效减轻中柱地震损伤程度，提高车站结构整体抗震性能。然而，仅在顶、底层中柱柱顶设置2层隔震支座时，会明显加重未设置隔震支座的中间层中柱地震损伤程度。此外，柱顶隔震支座的设置会削弱隔震体系的整体抗侧移能力，从而增大地铁地下车站结构地震侧移。总体上，建议采用各层中柱柱顶均设置隔震支座的措施提升地铁地下车站结构的整体抗震性能。

Seismic Performance of the Three-layer Three-span Subway Underground Station Structure With Seismic Isolation Bearings Fixed on the Top of Columns

According to the seismic response characteristics of the three-layer three-span frame subway underground station structure, the lead rubber seismic isolation bearings (LRB) were fixed at the different position of the top of columns, a two-dimensional finite element model for the static-dynamic coupling nonlinear interaction among the soil, the diaphragm wall and underground subway station structure was established, analyzing the influence of the position of the LRB fixed on the top of columns on the seismic response of subway station structure, such as the lateral deformation, earthquake damage, and dynamic stress response. It showes that the LRB fixed on the top of upper and lower columns, and fixed on the top of upper, middle and lower columns can effectively reduce the seismic damage of columns, thus improving the overall seismic performance of the isolation structure. However, when the LRB only fixed on the top of upper and lower columns, the seismic damage of the middle columns without the LRB would be severely aggravated. In addition, the LRB fixed on the top of columns can weaken the overall lateral resistance of the isolation structure, which slightly increased the seismic lateral response amplitude of the station structure. In general, it is recommended that the measure of setting the LRB on the top of columns in each floor to improve the overall seismic performance of the three-layer three-span subway underground station structure.