Numerical Assessment of Three-Dimensional Foundation Pinning Effects during Lateral Spreading at the Mataquito River Bridge

This paper presents a three-dimensional (3D) finite-element analysis of a bridge abutment and foundation system subjected to the kinematic demands of lateral spreading. The selected bridge system corresponds to the Mataquito River bridge in Chile. The 2010 Maule earthquake caused extensive lateral spreading on both river banks at this site. Observations suggest that 3D effects may have contributed to reducing the structural demands placed on the abutment and foundations during lateral spreading. Several 3D models representing the existing site geometry and a widened approach embankment are developed and used to estimate and compare bending demands in the shaft foundations supporting the bridge abutment. A simplified design method that accounts for pile pinning effects is also assessed as a possible tool to address this problem. (C) 2014 American Society of Civil Engineers.