基于位移的结构抗震设计方法探讨

Discussion of Displacement-based Seismic Design Method

根据钢筋混凝土框架结构的受力特点,把其等效为单自由度体系,推导等效单自由度体系的等效参数,阐述了直接基于位移的抗震设计方法的思路.将结构的性能划分为功能完好、功能连续、破坏控制、损失控制及生命安全5个性能水平,并用层间位移角限值予以量化.通过实例分析表明,基于位移的抗震设计比基于强度的抗震设计更能有效地把握结构在未来地震作用下的行为,同时该方法能对不同的性能目标进行多目标设计,满足业主对不同抗震设防目标的要求.

The multi-degree-of-freedom system is equivalent to the single-degree-of-freedom system according to the characteristics of RC frame structures.The equivalent parameters of the single-degree-of-freedom system are calculated.A newly-modified method of displacement-based seismic design is presented.The seismic performance is divided into five levels,i.e.function integrity,function continum,damage control,loss control and life-safety,and different levels are quantified with storey drift ratios.Compared with the force-based procedure on the deformation and the ration of reinforcement based on the seismic code,displacement-based seismic design is applied in case studying,it is revealed that the displacement-based seismic design can more effectively control the structure reaction under the earthquake,and the five performance levels are more easily used for the multi-levels design for satisfying the owner＇s different demands about anti-seisic performance objective.