Multi-Building Interactions and Site-City Effect: An Idealized Experimental Model

This chapter aims at identifying, describing and quantifying multi-building interactions and site-city effects through experimental, theoretical and numerical crossed-analysis. Multiple Structure-Soil-Structure interactions are investigated through an idealized experimental model of a city on a soft layer the properties of which are simple enough to be reproduced in numerical and theoretical models. The experimental set-up is designed to provide a good matching between the fundamental frequencies of the city and of the layer. Experimental results show (i) drastic changes in the layer’s response with two low amplitude resonance peaks favorable to longer coda and beatings and (ii) unconventional depolarization effects. The resulting data is compared with the theoretical city-impedance model derived by homogenization methods (Boutin and Roussillon, Bull Seismol Soc Am 94(1):251–268, 2004) and with a 2D hybrid BEM-FEM numerical model (Padron et al., Calculo de estructuras de barras incluyendo efectos dinamicos de interaccion suelo-estructura. Master thesis, Universidad de Las Palmas de G.C., Spain. http://hdl.handle.net/10553/10472, 2004). The specific features of multiple interactions are successfully reproduced by both models providing a qualitative and quantitative agreement with experimental results and with one another.