Seismic performance analysis for low-ductile R.C. frame structures based on IDA method

Frequent earthquakes strike China, leading the casualties and economic losses the highest level in the world. As observed from Wenchuan earthquake reconnaissance, it can be concluded that structures built according to different levels of seismic codes have different seismic capabilities, and those built before the year 1989 have insufficient capability. So in this paper, the development of Chinese Code for Seismic Design of Buildings is introduced, and then some differences between codes are summarized. Finally two R.C. frame structures with the same dimension and reinforcement ratio but different ductilities are modeled in OpenSees, and in order to obtain the weakness of seismic performance for the low-ductile one, their seismic performance are analyzed based on IDA method. Based on the previous research, the paper concludes that the performances of the two structures are significantly different under different waves. Seismic capability, especially the collapse-resistance capacity of the low-ductile one is much weaker than the newly-built one under severe earthquake. To reduce losses caused by earthquakes, we should pay more attention to developing the modeling methods and reinforcement measures for low-ductile structures.