Study On Seismic Behavior Of Zipper Frames

With the rapid development of China's economy,the high-rise and super high-rise buildings show good development trend.However,the resulting problems also gradually emerged.The structures will be more and more softer with the layer increasing,many scholars at home and abroad take outrigger in a structure to strengthen the structure stiffness.Now frame-core wall structure with strengthened story is the most commonly used structure system in high-rise and super high-rises buildings.However,there is little research on the steel structure with strengthened story.In this paper,the seismic performance of zipper frames with or without strengthened story was analyzed,and the contents are as followed:1)The seismic performance of zipper frame and traditional chevron steel braced frame system were compared.By a comprehensive consideration of the structure steel consumption and dynamic response under frequent and rare earthquakes,it is suggested that the zipper frame system is the preferred structural system compared with the chevron steel braced frame system.2)The seismic performance of zipper frame system with different design methods,including the sequential zipper column design method or not,the system with or without strengthened story,were compared.The story drift ratio for the structural system with strengthened story is slightly larger than the system without strengthened story,however,the cost of former system is lower by reducing the amount of steel.For the system with the discontinuous layout zipper column and strengthened story,the amount of steel is minimum compared with other systems,and the cross section of zipper column will not unlimited increasing.3)Considering the zipper frame system with or without strengthened story,the three-dimensional space models with the discontinuous layout zipper column,were established.The seismic performance of these structures models were conducted and the shear-lag effect was also analyzed.On the whole,the zipper frame system with strengthened story shows good seismic performance.And the two systems with or without strengthened story does not appear significant shear-lag effect.