Comparison of Fragility Assessment Isolated Structures Mounted on TCFP Bearings Subjected to Near Field and Far Field Earthquakes

In recent years, isolated systems are noted for preserving structures against harmful effects of earthquakes. Across all types of friction isolators, the latest one, triple concave friction pendulum, is transcending for its hardening behavior in high risk states. Isolated systems dissipate energy of earthquakes by increasing period and damping. In this paper, the behavior of structures (۳, ۶, and ۹ stories) mounted on TCFP subjected to near-field and far-field earthquakes are studied using fragility curves concept. Results indicate by increasing the effective period of TCFP decreases the median acceleration of collapse damage state (Sa-۵۰% collapse). For better understanding the behavior of TCFP isolators with different effective periods, collapse margin ratio is also used, that demonstrates isolator with higher period reduces collapse risk. Comparing Sa-۵۰% collapse in structure subjected to near-field and far-field earthquakes shows that the structure subjected to near field earthquake is less than the far field one.

Keywords:

Far field earthquakes , Near field earthquakes , seismic isolator , TCFP isolator , IDA , Fragility curve