Quantitative assessment of soil-structure interaction effects on seismic performance of bridges with ABC connections

Link to the Latest: September 2020 Progress Report

Background:
Successful implementation of accelerated bridge construction techniques in seismic regions can significantly reduce onsite construction time, traffic delays and associated costs. In the past, mostly experimental research has been used to achieve a better understanding of the seismic performance of ABC connections and, recently, full bridge systems. However, none of these studies have taken SSI effects into account causing doubts on the actual performance of these bridges in seismic regions. Moreover, systematic studies that focus on modeling the constitutive behavior of ABC components in numerical simulations are still lacking. 

To take advantage of rapid bridge construction in seismic areas, such as California, and at the same time improve the resilience of the transportation infrastructure, it is important to consider foundation flexibility as well as well-parametrized constitutive relations in modeling ABC bridge foundations and connections. We consider this proposal as a first step towards developing seismically resilient bridges with ABC connections where we use well-calibrated finite element models to quantitatively assess the effects of SSI on a two-span bridge system with different ABC connection types. 

Objective:
The main objective of this project is two-fold: (1) calibration of nonlinear numerical models that could capture the local and global behavior of one of the tested bridge systems, and (2) quantitative assessment of the seismic performance of the selected bridge with taking SSI effects into account. 

Scope:
This project focuses on quantitative assessment of soil-structure interaction effects on seismic performance of a two-span bridge with ABC connections. The following tasks will be performed to achieve the project objective:

  • Task 1 – Baseline finite element modeling
    • We will use the design and geometry details of a two-span bridge system with ABC connections to build a baseline finite element model.
    • We will compare the bridge response numerically and compare that against measured responses of the shake table test.
  • Task 2 – Data assimilation and nonlinear model calibration
    • To improve the predictive capability of the bridge model we will use the test data to calibrate the model and the underlying constitutive equations used for ABC connections.
  • Task 3 – Direct modeling of SSI effects
    • We will develop the finite element model of the soil-bridge system using domain reduction method and appropriate absorbing boundaries.
  • Task 4 – Quantitative assessment of SSI effects
    • We will use the developed calibrated model to perform a series of numerical experiments to assess the SSI effects on performance of ABC connections and the bridge itself. 

Research Team:
Principal Investigator:  Dr. Elnaz Seylabi
Co-Principal Investigator: Dr. Mohamed Moustafa
Research Assistant:  TBD