Experimental and analytical investigations of the piles and abutments of integral bridges.

This research investigated, through experimental and analytical studies, the complex interactions that take place between the structural components of an integral bridge and the adjoining soil. The ability of piles and abutments to withstand thermally induced cyclic loads was investigated by conducting large-scale cyclic load tests. Three pile types and three integral abutments with hinges were tested in the laboratory. Experiments simulated 75 years of bridge life. Numerical analyses were conducted to analyze the interactions among the abutment, the approach fill, the foundation soil, and the foundation piles. The results indicated that H-piles are most suitable for supporting integral abutments. Concrete piles and pipe piles were too stiff in response to repeated lateral loads, resulting in tension cracks at the connection with the abutment. Further, a hinge in the integral abutment effectively reduces pile stresses by absorbing some of the rotational movement.