8度区预应力混凝土框架地震反应分析

由于预应力混凝土结构自身的特殊性,其抗震性能受到广泛重视。为了考察预应力混凝土框架在高烈度区的抗震性能,根据预应力筋两阶段工作原理,利用OpenSees平台完成了两榀8度区抗震等级分别为一级和二级的预应力混凝土框架结构非线性动力反应分析,并进行了初步探讨。研究表明：在8度区严格按照国家规范设计的抗震等级为一级的预应力框架在罕遇地震作用下基本能够实现＂强柱弱梁＂,底层中柱柱脚为其薄弱部位;抗震等级二级的预应力框架对预应力梁＂超强＂的特点考虑不够充分,柱端弯矩增大系数偏低,在罕遇地震作用下柱端较梁端出铰早,转动大,可能形成层侧移机制。研究结果对我国结构设计规范优化柱弯矩增强系数取值有一定参考价值。

Seismic Response Analysis of Prestressed Concrete Frame in 8 Degrees Region

As a special system,prestressed concrete structure with its special performance is attractting more and more attentions on its seismic performance.For the purpose of investigate the actual seismic performance of this structure in high seismic zone,also according to the two-stage rationale,two sets prestressed concrete frames of two earthquake resistance rankⅠandⅡwere analyzed against the 8th seismic intensity with the help of OpenSees.Through nonlinear dynamic response analysis,the fowllowing is clear： under rare earthquake,prestressed concrete frame structure designed with the rankⅠbasically presented ＂strong column-weak beam＂ and thebaseof the interior column at the bottom story are the weak parts;while the rankⅡframe,whose column-end appeared a severe rotation and an earlier hinge than the beam-end,would probably formed storey-sway mechanism.The results are helpful to optimal evaluation of the column moment amplification factors in Chinese concrete structure design code.