边柱加强型预应力混凝土框架结构振动台试验研究

Shaking table test of a side-column-strengthened prestressed concrete frame structure

国内的既有预应力混凝土框架结构(简称PC框架)大都是基于《混凝土结构设计规范(GBJ 10-89)》(简称89规范)进行设计,研究表明,其耗能机制为层间屈服机制。为了提高结构的抗震能力,对基于89规范设计的三层两跨空间PC框架进行了边柱加强,并完成了1∶7.2缩尺模型振动台试验。试验表明:加强的边柱在地震作用下的破坏推迟,结构损伤在各楼层分布均匀,模型能够形成梁端和柱端出铰的混合出铰机制,结构整体抗震能力大大提高。此外,脉冲型近场地震动Chi-Chi波对结构的位移响应影响更大,而El Centro波则更容易激发模型的高阶振型。

The frame hinge mechanisms of the plenty of existing prestressed concrete frame structures （ PC frame structures） which were designed according to the 89 code are story sway mechanisms. In order to improve the seismic resistance of this kind of structures, a shaking table test on the 1 ： 7.2 reduced scale model of a modified 3 story-2 bay PC frame structure was carried out. The results indicated that the strengthened side columns＇ breakage was dispersed to all stories, the structure acted as a combined hinges damage was postponed, yield mechanism and the seismic resistance of the PC frame structure was improved. Comparing to the earthquakes of E1 Centro and Taft, the model responded more severely during the input of Chi-Chi earthquakes. E1 Centro triggers more easily higher-mode shapes than other earthquakes.