考虑塔楼偏心的大底盘层间隔震结构地震响应试验

Seismic Response Test of Mid-story Isolation Eccentric Structure with Tower-podium

为研究偏心大底盘层间隔震结构的地震响应,以指导这类竖向不规则结构的抗震设计.建立一个典型的偏心大底盘层隔模型结构,大底盘2层、塔楼6层,隔震层设置于塔楼底部.进行了层隔模型和对比抗震模型的数值分析和振动台试验,试验共16个工况.试验结果表明:塔楼各层加速度和层间位移减震效果显著;底盘加速度响应没有降低,层间位移减震效果不明显;在加速度0.4g和0.6g作用下底盘分别进入了弹塑性状态和达到中等破坏程度.建议工程应用中底盘受力构件应采取加强措施,提高底盘的弹塑性位移角限值.

The seismic response of mid-story isolation eccentric structure with tower-podium is investigated to guide the seismic design of such vertical irregular structures.A representative model of mid-story isolation eccentric structure with a large podium was fabricated.The large podium has two stories and the tower has six stories.The isolation layer is located at the bottom of the tower.Numerical analysis and shaking table test were conducted on a mid-story isolation model and an anti-seismic model without an isolation system to compare their seismic response.These models were subjected to bidirectional seismic waves,and a total of 16 test scenarios were obtained.The results show that for the mid-story isolation model,the story acceleration and story drift of each story of the tower decreases sharply,indicating an excellent damping effect on the tower.The story acceleration response and the story drift of the podium increase slightly,which indicates that there is almost no damping effect on the podium.The podium enters into the elastic-plastic stage under the peak acceleration of 0.4 g,and a medium damage level was reached under the peak acceleration of 0.6 g.It is thus suggested that the stressed components of the podium should be strengthened,and the limit of elastic-plastic displacement angle of the podium should be increased in engineering application.