Seismic Collapse Resistance of Multi-story Buildings Focus on Structural Low-Cycle Fatigue Characteristic

Abstract

Based on the low-cycle fatigue tests of fourteen identical half-scale concrete columns, the collapse index of earthquake-resistant structures is presented in this paper. The influence of post-yield stiffness and floor yield strength coefficient of structures on the dynamic behavior of structural response is studied based on a large number of time-history analyses. Other influence factors, such as site category, basic period, are also addressed in this paper. The analytical results show that the influence of the site category on collapse response is determined by its contribution to earthquake wave amplitude, frequency spectrum and duration. The negative stiffness of post-yielded structure has a significant influence on the collapse response of structures. By using the floor yield strength coefficient, structures are categorized into three types: strong, moderate and weak. For the strong structure, it is easy to ensure the safety under the rare earthquake; for the weak structure, the story drift can be checked following the current code; and for the moderate structure, the method suggested in this paper can be utilized to check the equivalent ductility considering low-cyclic fatigue characteristic and ensure the safety under the rare earthquake.

This work is partially supported by the National Natural Science Foundation under Grant #51078037 to B.Q. Liu.