Bridges, Tunnels and other Transportation Structures
The conventional design of substructure for bridges is based on the concept of ductility which allows the structure to maintain sufficient strength at large deformations. By restraining the foundations leads to severe damages for higher magnitude of earthquakes. Rocking can act as a form of isolation, reducing force demands on a bridge and thereby achieving better economy than the conventional design practice of bridge pier foundation. This paper proposes a novel resilient pier with elastomeric pad installed at top of pile cap along with external restrainers made up of shape memory alloy (SMA) bars. The effect of pile soil interaction along with ground response analysis is incorporated in the individual pier model adopted for the study. The response of soil profile was analyzed using a 1D equivalent site response program to study the amplification/deamplification of earthquakes waves at ground surface. By performing non-linear dynamic time history analysis, a seismic assessment of a fixed based pier at pile cap top and the proposed resilient pier is evaluated. It has been found that the novel resilient pier supported on pile foundation has good recentering capability and better seismic performance than the conventional one as it is subjected to lesser forces and negligible permanent drifts due to its controlled rocking behaviour.