既有结构外套增层隔震加固振动台试验研究

Shake table test of existing structure with external structure reinforcement and mid-story isolation rehabilitation

应用外套结构加固方法及加层减振体系的设计方法,对既有14层剪力墙结构进行外套增层隔震加固设计,研究增层隔震对加固效果的影响。建立1/6缩尺结构试验模型,设计橡胶隔震支座,通过调整隔震层刚度完成层间隔震结构与非隔震结构的振动台试验。对比分析隔震与非隔震结构前两阶频率变化,分析隔震与非隔震结构位移、加速度、混凝土应变响应以及破坏现象的区别。结果表明:增层隔震加固体系能够明显延长结构的二阶周期,并有效地控制结构地震响应;外套结构与原结构协同作用良好,均未发生破坏;既有结构外套增层隔震加固设计方法是可行性的。研究为既有结构抗震加固设计提供有益借鉴。

The external structure reinforcement and mid-story isolation rehabilitation method was proposed for the existing 14 story shear wall structure, and then its reinforcement and seismic isolation effects were investigated. One 116 structure model was established by employing external structure reinforcement and by adding isolation layer and 2-story steel frame on the top of shear wall structure, the rubber isolation bearings between shear wall structure and 2-story steel frame were designed, and furthermore shake table tests for the structures with and without isolation layer were carried out, respectively. The differences in the first-order and second-order frequencies were evaluated, and then the displacement, acceleration, and strain responses of the structures with and without isolation layer were analyzed comparatively. The results show that the isolation system can significantly extend the second-order period of structure and effectively control the seismic responses, the external structure may collaborate well with the existing structure, and no disjunction occurs during the tests, indicating that the proposed method is very effective. The results may provide some valuable guidelines for reinforcing the existing structures.