Spatial variability of the urban ground motion in a highly heterogeneous site-city configurations

Free-field conditions on the ground surface are widely used to assess the local seismic response. Nevertheless, this assumption is a very strong approximation in urban areas since the dynamic interaction between the urban agglomerate and the soil cannot be neglected. Several studies evidenced the tr...

Full description

Saved in:
Bibliographic Details
Published in:Bulletin of earthquake engineering 2021, Vol.19 (1), p.27-45
Main Authors: Varone, C., Lenti, L., Martino, S., Semblat, J. F.
Format: Article
Language:English
Subjects:
Alluvial basins
Amplification
Approximation
Buildings
Civil Engineering
Configurations
Earth and Environmental Science
Earth Sciences
Environmental Engineering/Biotechnology
Finite element method
Geophysics/Geodesy
Geotechnical Engineering & Applied Earth Sciences
Ground motion
Heterogeneity
Hydrogeology
Kinetic energy
Mathematical analysis
Mathematical models
Original Research
Sciences of the Universe
Seismic activity
Seismic response
Soil
Soil dynamics
Soils
Spatial variability
Spatial variations
Structural Geology
Two dimensional models
Urban areas
Urbanization
Variability
Vibrations
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Free-field conditions on the ground surface are widely used to assess the local seismic response. Nevertheless, this assumption is a very strong approximation in urban areas since the dynamic interaction between the urban agglomerate and the soil cannot be neglected. Several studies evidenced the transmission of vibrations from the buildings to the soil and the multiple interactions between a building network and the site through so-called Site-City Interaction (SCI). This paper focuses on the spatial variability of the seismic ground motion due to SCI in the case of highly heterogeneous site-city configurations. The Fosso di Vallerano valley in Rome (Italy) has been chosen as a case study because of the high heterogeneity of the deposits which characterize the local geological setting as well as the intensive urbanization. A proper 2D numerical modelling (Finite Elements Method) of the seismic response in free-field conditions as well as with the city agglomerates (SCI-based condition) has been performed. The numerical results show a strong spatial variability of the wave field induced by the presence of the buildings and their interaction with the heterogeneous soil. The SCI effect causes a strong or global reduction of ground motion, amplification levels and kinetic energy close to the buildings. Induced perturbations affect the ground motion along the surface of the model, increasing the amplification values and the kinetic energy in the vicinity of the buildings. These findings highlight that buildings generate significant variability effects all around their foundations as well as in the entire alluvial basin.
ISSN:1570-761X
1573-1456
DOI:10.1007/s10518-020-00965-2