FRAGILITY ASSESSMENT OF THE INTER-STORY POUNDING RISK BETWEEN ADJACENT REINFORCED CONCRETE STRUCTURES BASED ON PROBABILISTIC SEISMIC DEMAND MODELS

The aim of this study is the probabilistic evaluation of the seismic performance of a multistory reinforced concrete (RC) frame structure due to the inter-story pounding effect. The assessment is performed through fragility curves at different performance levels. For this purpose, different probabilistic seismic demand models (PSDMs) are developed based on the real seismic response of the RC structure as a function of the spectral acceleration (Sa). In this direction, the inter-story (floor-tocolumn) pounding between an 8-story RC frame structure and a 3-story rigid barrier (very stiff structure) is examined. Three different initial gap distances (dg) between the adjacent structures are considered. The seismic fragility assessment of the 8-story RC structure without the inter-story pounding effect is also incorporated. Results indicate that the local performances of the columns of the 8-story RC structure are crucial demand parameters for the probabilistic assessment of the inter-story pounding risk. The fragility curves are shifted to lower values of Sa due to the pounding effect in comparison to the corresponding cases without pounding, while the probability of pounding between the examined structures is increased as the separation gap distance dg decreases. Nevertheless, the more exigent the performance level is the fragility curves move towards greater values of earthquake intensity.