基于地震均匀损伤的钢筋混凝土框架结构新型侧向力模式

A new lateral force pattern of reinforced concrete frame structures based on seismic uniform damage

结构在强震下形成均匀损伤状态时,各楼层的层间侧向变形近似相等、损伤大小相同,结构各部位的材料性能均得到充分发挥,易于形成整体化的屈服模式和耗能机制。基于优化准则法,考虑结构的整体损伤和局部损伤大小,构建了钢筋混凝土框架结构地震均匀损伤优化设计程序;基于非线性温克尔地基梁模型(BNWF),建立了能够考虑土结构动力相互作用的钢筋混凝土框架结构分析模型。分别以5层和8层结构为例,对其进行均匀损伤优化设计和关键收敛参数分析,对比研究了优化前后结构配筋、梁柱转角和结构最大层间位移角的变化情况。基于两个均匀损伤优化设计结构的层剪力分布,以中国抗震规范的侧向力模式为基础,提出了新型抗震设计侧向力模式。

When the uniform damage state of structures is developed under strong earthquakes,each story has an approximately equal story drift ratio and damage,and the material potential of each structural components is fully exploited,which makes for the global yielding mode and energy dissipation mechanism.By considering the global and local damage,the optimization design procedure of seismic uniform damage of reinforced concrete frame structures was firstly constructed based on the optimality criteria method.The analytical model of reinforced concrete frame structures considering the soil-structure-interaction was developed based on the Beam on Nonlinear Winkler Foundation(BNWF)model.Two 5-and 8-reinforced concrete(RC)frame structures were employed as the prototype structures.The uniform damage optimization design was performed and the influence of main convergence parameters were analyzed.The structural reinforcements,component rotations and maximum interstory drift ratio before and after optimization were compared.According to the story shear distribution of two optimized RC frames,a new lateral force pattern for seismic design was proposed using the format of Chinese seismic design code.