节点变形对在役混凝土框架地震易损性影响分析

EFFECT OF JOINT DEFORMATION ON EXISTING RC FRAME STRUCTURE SEISMIC VULNERABILITY

在设计中按照"强节点、弱构件"的原则进行结构设计,地震作用下,节点区域的变形很小,因此在结构分析中节点通常假定为刚性。随着结构龄期变化,结构将产生耐久性损伤,节点区域变形增大,此时要通过节点区域的直接建模来考虑其变形对结构抗震性能的影响。以典型6层混凝土框架为例,用两种不同节点建模方法建立整体结构模型,对不同龄期的结构进行易损性分析,建立了结构的时变易损性模型。研究表明,考虑节点区域变形的结构失效概率偏大,其偏差幅度和速率随着龄期和峰值加速度的增大而增大。

When designing structure, according to the principle of strong node and weak member, the joint deformation is very small under the earthquake action,so it is always assumed to be rigid in structure analysis.However,durability damage is caused and the joint deformation increases rapidly with the accelerated aging time,as a result,direct joint modeling is needed to study the effect of joint deformation on seismic behavior. taking a six-story RC frame for example,two different joint modeling methods were adopted when modeling a whole structure. By analyzing the vulnerability of the structure with different age,the time-varying vulnerability model was built finally.The results showed that the value of structural failure probability is larger when considering the joint deformation,whose deviation and rate were increased with age and peak acceleration.