Influence of Buildings Spacing in Site-City Interaction Effects

Ricardo Taborda, & Yigit D. Isbiliroglu

Published August 15, 2017, SCEC Contribution #7746, 2017 SCEC Annual Meeting Poster #240

We present initial results from a study focusing on the influence of the compactness of a city on the response of the ground and the dynamic behavior of buildings. It is well-known that individual soil-structure interaction effects are important because they change the effective base motion used in the engineering design of buildings. However, collective soil-structure interaction effects (also called site-city interaction effects) are not fully recognized yet, mainly because it is a phenomenon that has proven elusive to be detected through direct observations or laboratory experiments. Simulations, then, provide a path to better understand the existence and extent of these effects, which are particularly important because they increase the spatial variability of the ground motion and can modify the dynamic response of the structures. Among other factors, previous studies have suggested that the density and configuration of buildings in densely urbanized areas within a city can play a significant role in the coupled effects of individual and collective soil-structure interaction, affecting the way the buildings exchange and transfer energy through and back into the ground. In this study we focus our attention on the effects that the compactness of urbanized areas have on the ground motion and on the dynamic response of buildings. We conduct a series of three-dimensional ground motion simulations including simplified models of buildings in realistic basins. We use a finite element end-to-end procedure that synthesizes the earthquake source, path, basin and site-city effects in a single model. We investigate the effects that the buildings have on the ground motion and on each other in relation to the compactness of the city configurations. We are particularly interested in identifying the best approach to define the compactness in relation to the effects observed in the structural response of buildings as a factor to be considered in urban building design in the future. Our simulations also shed light on the effect that urban settings have on the ground motion and provide insight into the spatial variability added by the foundation-structure systems, and how this can affect the interpretation of ground motions in urban areas.

Key Words
soil-structure interaction, site-city interaction, ground motion modeling, simulation

Citation
Taborda, R., & Isbiliroglu, Y. D. (2017, 08). Influence of Buildings Spacing in Site-City Interaction Effects. Poster Presentation at 2017 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Engineering Implementation Interface (EEII)