Seismic responses analysis of rigid frame bridges with footing uplift considering soil-structure interaction

Rocking isolation is an effective method for reducing structural damage during earthquakes and aligns with a seismic design approach that aims to minimize damage to bridges. The seismic responses of rocking structures are significantly influenced by the soil-structure interaction and the soil characteristics. In this research, a shaking table test was conducted on a single-pier rigid-frame bridge model with an uplifting footing, considering soil-structure interaction. This test was used to validate a finite element model (FEM) developed using ABAQUS software. Subsequently, the seismic responses of the rigid-frame bridge with a pile foundation capable of rocking at the pier base were analyzed in detail. Four soil types, including silt, silt clay, sand, and clay, were examined, and two foundation types were considered: a fixed pile foundation and a rocking pile foundation. The results indicate that uplifting the footing can reduce the deck's acceleration and the pier's bending moment, while increasing the bridge's displacement, compared to a bridge with a fixed pile foundation.