Generalized Fragility Relationships with Local Site Conditions for Probabilistic Performance-based Seismic Risk Assessment of Bridge Inventories
Abstract: The current practice
of detailed seismic risk assessment cannot be easily applied to all the bridges
in a large transportation networks due to limited resources. This paper
presents a new approach for seismic risk assessment of large bridge inventories
in a city or national bridge network based on the framework of probabilistic
performance based seismic risk assessment. To account for the influences of
local site effects, a procedure to generate site-specific hazard curves that
includes seismic hazard microzonation information has been developed for
seismic risk assessment of bridge inventories. Simulated ground motions
compatible with the site specific seismic hazard are used as input excitations
in nonlinear time history analysis of representative bridges for calibration. A
normalizing procedure to obtain generalized fragility relationships in terms of
structural characteristic parameters of bridge span and size and longitudinal
and transverse reinforcement ratios is presented. The seismic risk of bridges in
a large inventory can then be easily evaluated using the normalized fragility
relationships without the requirement of carrying out detailed nonlinear time
history analysis.
Keywords: Bridges, concrete
structures, fragility relationships, performance-based earthquake engineering,
seismic risk and vulnerability
Author: Lau, D.T.,
Vishnukanthan, K., Waller, C.L., Sivathayalan, S
Journal Code: jptsipilgg120031
