钢筋混凝土柱对应于各地震损伤状态的侧向变形计算

采用半经验半理论的方法对以受弯为主的钢筋混凝土柱对应于各主要损伤状态的侧向变形进行了研究。本文研究的主要损伤状态包括屈服、混凝土保护层压碎、剥落、纵向受力钢筋屈曲、极限状态五个状态。首先建立了各损伤状态下柱截面受压区高度的计算方法。接着,利用对美国太平洋地震工程研究中心(PEER)建立的钢筋混凝土柱的试验数据库的统计分析,采用平截面假定和钢筋混凝土受弯构件的塑性铰理论推出了混凝土保护层压碎时压区边缘混凝土的应变大小,混凝土保护层剥落、纵筋屈曲和进入极限状态时核心区混凝土边缘的压应变大小,进而建立了钢筋混凝土柱对应于各损伤状态的变形计算方法。利用本文提出的方法得到的变形计算值与PEER提供的试验数据在统计意义上有较好的一致性。该方法可为钢筋混凝土柱基于位移的抗震设计和抗震性能评价提供依据。

Lateral displacement estimation for RC columns in different seismic damage states

Lateral displacement in different seismic damage states for flexure-dominant reinforced concrete(RC) columns is studied by semi-empirical method.The principal damage states studied here include yielding,crushing and spalling of cover concrete,bucking of longitudinal bar,and ultimate limit state.Firstly,the method is developed to estimate the compression zone depth of column section in different damage states.Secondly,the stain of the extreme compression fiber of the gross section in the state of crushing of concrete cover and the strain of the extreme compression fiber of the confined core section in the state of spalling of concrete cover,longitudinal bar buckling,and ultimate limit state are individually derived on the basis of the plane-section hypothesis,plastic-hinge method,and statistical analysis of the database containing the results of cyclic tests on RC columns assembled at the Pacific Earthquake Engineering Research Center(PEER).The method to predict the lateral displacement in individual damage states is proposed accordingly.The predicted results by this method have good agreement with the database provided by PEER in the statistical sense.This method can be used as the basis for the displacement-based seismic design and the estimation of seismic performance for RC columns.