Seismic Soil-Structure Interaction in Bridges: Does the Answer Lie in Soil Or Structure?


Abstract eng:
Effect of soil-structure interaction (SSI) and pier-column inelasticity on the seismic response of a 4-span bridge typically used for urban elevated highways was investigated using FEM analytical models and sub-structuring scheme. The bridge system was designed in a moderate seismic zone for five soil conditions with deep foundations and five rock profiles with shallow foundations. Impedances of both types of foundation systems were computed by methods available in the literature. Nonlinear behavior of the reinforced concrete pier column was modeled for material and geometric non-linearities and incorporated in the analysis scheme by equivalent linear model. Foundation impedance was modeled as Winkler springs in six directions. FEM model of the bridges was subjected to fifteen actual ground motions varying in PGA from 0.01g to 0.64g. Results of more than 300 FEM analysis cases were evaluated to delineate the relative contribution of the elastic part, SSI and pier column non-linearity to bridge displacement, column shear force and modal parameters. Contribution to all three parameters was the largest for the elastic part (60% to 95%) followed by pier column inelasticity (4% to 25%) and SSI (1% to 15%) for various combinations of investigated parameters. Contribution of SSI to bridge displacement and column shear force was found to be significant only in bridges founded on weaker rock (Rock Class IV and V) and weaker soil (Site Class III). Contribution of pier column inelasticity was significant for more than 86% of the bridge analysis cases. It was thus concluded that pier column inelasticity contributed more significantly to the bridge design parameters than SSI in the class of bridges examined in the study.

Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.



Record appears in:



 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 157.:
Download fulltext
PDF

Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)