近海大气环境下多龄期典型钢筋混凝土剪力墙结构地震易损性研究

RESEARCH ON SEISMIC FRAGILITY OF MULTI-AGED RC SHEAR WALL STRUCTURES IN OFFSHORE ATMOSPHERIC ENVIRONMENT

近海大气环境下,钢筋锈蚀会导致剪力墙结构抗震性能发生退化,有必要建立锈蚀钢筋混凝土(RC)剪力墙结构的地震易损性模型。以典型剪力墙结构为研究对象,基于PERFORM-3D,主要通过材料劣化原理考虑近海大气环境下的钢筋锈蚀,采用纤维模型建立RC剪力墙结构的数值模型;以峰值地面加速度(PGA)作为地震动的强度指标,分别对22条地震波进行地震动调幅,得到不同龄期下不同层数对应典型结构的需求模型参数;定义多龄期RC剪力墙结构性能指标限值,对8度设防下不同龄期对应不同层数的典型剪力墙结构进行地震易损性分析。结果表明:随龄期增加,不同层数的典型剪力墙结构对应各极限状态超越概率均不断增加。

In the offshore atmospheric environment,the corrosion of steel bars will lead to the seismic behavior of shear wall structures degenerated.It is necessary to establish the seismic fragility model of corroded RC shear wall structures.The typical shear wall structure was taken as the research object.Based on PERFORM-3D,the corrosion of steel bars in the offshore atmosphere was mainly considered by the principle of material degradation,and the numerical models of RC shear wall structures were established by fiber model.Taking PGA as the intensity index of ground motion,22 seismic waves were amplitude modulated,and the demand model parameters of typical structures corresponding to different layers with different ages were obtained.The performance index limit of multi-aged RC shear wall structures was defined,and the seismic fragility analysis of typical shear wall structures of different layers with different ages under the condition of seismic fortification intensity 8 was carried out respectively.The results showed that with the increase of age,the probability of exceeding limit state of typical shear wall structures with different layers increased.