Numerical Simulation of Impact Effect for Damage Assessment of Highway Bridge Abutments

Damage to bridge abutments due to girder impact has been observed in many major earthquakes. Very limited studies have been conducted. None of the past studies has incorporated abutment damage as an integrated system, i.e., the interaction between the deck and the back wall as well as between abutment and backfill. First, the reliability of the numerical model for damage assessment is validated with the result of the shaking table test. Second, numerical simulations of the impact effect were carried out on four types of actual abutments with different wing wall shapes and dimensions. The developed numerical models can simulate the nonlinear backfill soil, the interface between the backfill and the back walls, damage to the concrete, and the yielding of the reinforcement steel with the strain rate effect of the concrete and steel reinforcement. Parametric studies were conducted to investigate the influence of the nonlinearity of the backfill soil, back wall-to-backfill friction, constitutive law of concrete, hourglass ratio, and impact energy. The results show that the displacement and the impact force on the back wall are affected by the nonlinear behavior of the backfill soil and wing wall. Since poundings can be repetitive, this study confirms that the velocity of the initial impact of a bridge deck can precisely predict the severe damage to bridge abutments.