自控耗能无黏结预应力框架抗震能力的能力谱法研究

Seismic capacity of self-control energy dissipation UPPC frame based on capacity spectrum method

自控耗能无黏结部分预应力混凝土(UPPC)框架指的是在UPPC框架中采用折线型无黏结预应力筋,并在无黏结预应力筋转折处合理设置自控耗能元件来调减罕遇地震作用下无黏结预应力筋的应力,使得在罕遇地震作用时释放梁内部分预应力,形成梁铰耗能机制,从而形成强柱弱梁的延性框架。基于能力谱法,采用ABAQUS有限元软件对已有的两榀试验框架(普通UPPC框架KJ1和自控耗能UPPC框架KJ2)进行了地震烈度7度、8度和9度罕遇地震作用下的有限元分析。分析结果表明:在抗震设防烈度7度和8度罕遇地震下,两榀框架抗震能力基本相同;9度罕遇地震下,KJ1框架不存在性能点,即KJ1框架无法抵抗9度罕遇地震,KJ2框架的顶层位移虽然超过规范规定的钢筋混凝土框架结构弹塑性限值,但KJ2框架抗震能力仍优于KJ1框架。

A self-control energy dissipation unbonded partially prestressed concrete ( UPPC) frame refers to the rational setting of self-control energy dissipation components in the UPPC frame,which aims at reducing the stress of unbonded prestressing reinforcement during severe earthquakes. Besides,part of the prestress in the beam during that period can be released to form a beam-hinge energy dissipation mechanism and strong column-weak beam ductile frame. Based on the capacity spectrum method,the finite element analyses of two existing test frames ( UPPC frame KJ1 and self-control energy dissipation UPPC frame KJ2) under 7 degree,8 degree and 9 degree rare earthquakes were carried out by ABAQUS finite element software in this paper. The results show that rare earthquakes,the seismic capacities of the two frames are basically the same under 7 and 8 degree. Under 9 degree rare earthquake,KJ1 has no performance point,and KJ1 is unable to resist the 9 degree rare earthquake. Although the top displacement of KJ2 is more than the elasto-plastic limit of the standard reinforced concrete frame structure,it is still shown that the seismic capacity of KJ2 is better than that of KJ1.