基础隔震大跨异形钢连廊连体结构地震易损性分析

针对地震中大跨连廊与主体结构连接处容易破坏的特征，以某大跨异形钢连廊连体结构为研究对象，开展基础隔震与非隔震连体结构的地震易损性对比分析。首先，对原连体结构进行基础隔震设计，并采用有限元软件SAP2000分别建立隔震与非隔震连体结构的数值模型。然后，定义隔震连体结构中框架 剪力墙结构、连廊橡胶支座端、连廊预埋锚固端和基础隔震支座的损伤指标，并选取24条地震动记录，对隔震连体结构进行了三向地震激励下的增量动力分析。最后，对隔震与非隔震大跨异形钢连廊连体结构局部和整体的地震易损性进行对比。结果表明：在8度罕遇地震作用下，基础隔震连体结构中各损伤指标出现毁坏的超越概率值较非隔震连体结构减小，其中连廊预埋锚固端出现毁坏的超越概率减小46.19%；结构整体出现毁坏的超越概率的上、下界分别减少72.56%与82.62%。这说明基础隔震能显著降低连体结构地震时发生损坏的概率，提高连体结构的抗震性能。易损性分析结果显示隔震连体结构易发生损坏的部位依次是基础隔震支座、连廊预埋锚固端、主楼、附楼I和连廊橡胶支座端，这个顺序与非隔震的连体结构基本一致。因此，建议在连体结构的隔震设计中，宜采用具有高剪切应变的基础隔震支座，并仍需加强连廊锚固端的连接措施。

Seismic fragility analysis of base-isolation structure connected #br# with large span special-shaped steel corridor

The connecting parts between the large span corridor and the main structure are easily to suffer damage under earthquake. To solve this problem, a structure connected with large span special-shaped steel corridor was analyzed and its seismic vulnerability laws with and without base-isolation structures were compared. Firstly, the base isolation design for the original connected structure was carried out, and the numerical models of isolated and non-isolated connected structures were established using SAP2000, respectively. Secondly, the damage indexes for the frame-shear wall structure, corridor’s rubber bearing, embedded parts and base-isolation bearing were defined, respectively. The incremental dynamic analysis was carried out under three-dimensional seismic excitation with 24 ground motion records as input data. Finally, the comparative analysis of seismic fragility between local and overall structure with and without base isolators was carried out. The results show that under the rare intensity level of degree 8, the failure probability of the base-isolation connected structure is lower than the non-isolation connected structure. The failure probability for corridor’s embedded parts are decreased by 46.19%, and the upper and lower bound of the failure probability for the overall structure are decreased by 72.56% and 82.62%, respectively. It is proven that the base isolation can significantly decrease the damage probability and improve the seismic performance of the connected structure. The most vulnerable local structures of the base-isolation connected structure are in turn base-isolation rubber bearing, the embedded parts，the main building，the affiliated building I and the rubber bearing of corridor. The similar damage sequence can be seen in the non-isolation connected structure. Therefore, it is suggested to use the base-isolation rubber bearing with high shear strain, and strengthen the connection measures of embedded parts of corridor in the base isolation design of the connected structure.