Effects of low intensity earthquakes preceding the design earthquake, on the gap distances between structures used to prevent pounding

In this study, the effect of possible structural damage resulting from low-intensity earthquakes on the pounding behavior of structures was examined. For this investigation, structural models that consider nonlinear behavior were established. For the analyses, six, nine and ten-story reinforced concrete frames were modeled next to each other, and a simple modeling approach, which represent the pounding points, was used to model the space between the structures. Although the approach used does not fully reflect the pounding behavior between structures, it can be used to determine whether pounding has occurred and to relatively measure the severity of possible pounding. In scope of the study, eleven ground motion records were determined and scaled. The used ground motion records were taken from areas far from the fault and do not show velocity pulse-like features. The results of the study revealed that the risk of pounding caused by main earthquakes following low-intensity foreshocks was generally higher than that of main earthquakes do not preceded by foreshocks. It was observed that the extent of pounding behavior increases together with the intensity of foreshock. Also it is found that structures with very similar story numbers and dynamic properties may not be exposed to pounding owing to similar displacements under earthquake loads.