成都博物馆基础隔震不规则结构扭转效应控制研究

Torsional effect control of irregular base isolation structure of the Chengdu Museum

针对成都博物馆不规则基础隔震结构,分别建立8度(0.2g)地震作用隔震模型及7度(0.15g)地震作用非隔震模型,在多遇地震作用下,对两种模型结构体系的振型(包括平动分量和扭转分量)、扭转位移、扭转加速度、扭转剪力以及结构构件扭矩进行了对比分析。研究结果表明:基础隔震措施有效地控制了不规则结构的扭转效应;以前二阶振型的扭平分量比(扭转振型分量与平动振型分量之比)小于0.15,扭转位移比(楼层最大弹性水平位移与该楼层两端弹性水平位移平均值之比)小于1.2,扭转剪力比(垂直于地震输入方向的构件扭转剪力与地震输入方向的构件剪力之比)小于0.2为控制指标来控制结构的扭转效应。

Based on the irregular base isolation structure of the Chengdu Museum, the model under seismic fortification level 8 （0.2g） with base isolation and the model under seismic fortification level 7 （0. 15g） without base isolation were established. Under the action of frequent earthquake, the vibration mode （including translational component and torsional component） , torsional displacement, torsional acceleration, torsional shear, and torque of structural members of the two models were compared and analyzed. The results show that the base isolation can effectively reduce the torsional effects of the irregular structure. To limit the torsional effect of the structure, the ratio of torsional component to translational component of the first two vibration modes should be less than 0.15. The ratio of the maximum elastic horizontal displacement of the floor to the average elastic horizontal displacement of the two ends of the floor should be less than 1.2. The ratio of the torsional shear force of the member perpendicular to the seismic input direction to the shear of the member in the seismic input direction should be less than 0.2.