Effects of realistic topography on the ground motion of the Colombian Andes - A case study at the Aburra Valley, Antioquia
Por:
Restrepo, D., Bielak, J., Serrano, R., Gómez, J., Jaramillo, J.
Publicada:
1 mar 2016
Resumen:
This paper presents a set of deterministic 3-D ground motion simulations
for the greater metropolitan area of Medellin in the Aburra Valley, an
earthquake-prone region of the Colombian Andes that exhibits
moderate-to-strong topographic irregularities. We created the velocity
model of the Aburra Valley region (version 1) using the geological
structures as a basis for determining the shear wave velocity. The
irregular surficial topography is considered by means of a fictitious
domain strategy. The simulations cover a 50 x 50 x 25 km(3) volume, and
four M-w = 5 rupture scenarios along a segment of the Romeral fault, a
significant source of seismic activity in Colombia. In order to examine
the sensitivity of ground motion to the irregular topography and the 3-D
effects of the valley, each earthquake scenario was simulated with three
different models: (i) realistic 3-D velocity structure plus realistic
topography, (ii) realistic 3-D velocity structure without topography,
and (iii) homogeneous half-space with realistic topography. Our results
show how surface topography affects the ground response. In particular,
our findings highlight the importance of the combined interaction
between source-effects, source-directivity, focusing, soft-soil
conditions, and 3-D topography. We provide quantitative evidence of this
interaction and show that topographic amplification factors can be as
high as 500 per cent at some locations. In other areas within the
valley, the topographic effects result in relative reductions, but these
lie in the 0-150 per cent range.
Filiaciones:
Restrepo, D.:
Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
Departamento de Ingeniería Civil, Universidad EAFIT, Medellín, Colombia
Bielak, J.:
Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
Serrano, R.:
Applied Mechanics Group, Universidad EAFIT, Medellín, Colombia
Gómez, J.:
Departamento de Ingeniería Civil, Universidad EAFIT, Medellín, Colombia
Jaramillo, J.:
Departamento de Ingeniería Civil, Universidad EAFIT, Medellín, Colombia
Bronze
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