Influence of site-city interaction on the response of structures considering soil stiffness, height, and number of buildings

摘要

Simultaneous effects of soil and a number of adjacent structures sitting next to each other is perceived as the site-city interaction (SCI). To better analyze the seismic behavior of the structures, the inclusion of the SCI appears to be essential. Accordingly, the SCI is affected by a number of parameters such as soil profile, urban congestion, as well as dynamic properties of buildings and soil layers. In this study, considering four soil types according to Eurocode8 (EC8) and a series of structures in single and multiple configurations (buildings arranged in 3 x 3 and 5 x 5 groups) representing an ideal city, 3D dynamic analyses were conducted using SASSI2000 software. Then, the acceleration response of the structures placed in the middle of each configuration was compared with that of the single structures to evaluate the influence of soil properties particularly, its stiffness as well as number and height of the structures on the response of the base and top nodes of multi-degree-of-freedom structures incorporating the SCI effects. Based on the results, the inclusion of SCI reduced the acceleration values especially at top of the structure (7% and 15% for the bottom and top of the structure on average). In addition, as soil stiffness decreases and the number of buildings increases, the influence of SCI becomes profound. According to the complexities of the SCI, to acquire more accurate results, further parameters such as the type of seismic waves, irregularity of buildings, and faulting mechanism have to be taken into account.