Relationship between ground motion parameters and seismic gap distances of adjacent RC frame buildings

Abstract

This study aims to investigate the relationships between ground motion parameters (GMPs) and seismic gap distances of adjacent low and mid-rise RC buildings. A total of 22 GMPs were taken into account as Intensity Measures (IM) input. In addition to the 20 different GMPs, the spectral acceleration values of the dominant period of the adjacent buildings were also included for each acceleration record. 28 different binary building models (three dimensional, 3D) were created among reinforced concrete buildings ranging from 3 to 10 stories. 616 nonlinear time history analyses were performed using 22 different acceleration records to obtain the minimum required seismic gap distances between binary building models. The correlation between GMPs and separation distances between neighboring buildings was also investigated. The outcomes show that velocity-related GMPs such as Housner Intensity (HI), Velocity Spectrum Intensity (VSI) are very effective in estimating the seismic gap distances of adjacent buildings. Also, spectral acceleration values of adjacent buildings exhibit strong correlation. Whereas, acceleration, frequency and displacement related parameters have moderate or low correlation. In particular, PGA, one of the frequently considered parameters in performance-based earthquake engineering (PBEE), has a low correlation. This study has developed ground motion parameters-based approaches that can estimate the seismic gap value between adjacent buildings using the three GMPs with the highest correlation values. The correlation values for the proposed approaches for HI, S_a1(T₁), and VSI parameters were obtained as 0.91, 0.89 and 0.89, respectively. Compared to the DDC method in the literature, these parameters have higher correlation and lower error metrics. The proposed ground motion parameters-based approaches in this study are simple and useful for the evaluation of existing low and mid-rise RC buildings.