Abutment Pile Design for Jointless Bridges

Abutment piles for a jointless bridge are subjected to lateral displacement as the bridge superstructure expands and contracts. The piles must be designed to satisfy the strength criteria of a structural member and the load transfer requirements and support resistance of the surrounding soil. Two design alternatives for the pile capacity are presented. Results for both design alternatives are shown to be conservative when compared with the solutions obtained from a previously developed finite element model. Alternative one, involving elastic behavior, is recommended for piles with insufficient moment-rotation capacity, while alternative two, involving inelastic behavior, is recommended for piles having a moment-rotation capacity that exceeds the moment-rotation demand at plastic hinge locations. Specific expressions for the ductility requirements for alternative two are specified for both uniaxial and biaxial bending conditions. When the piles have sufficient ductility, alternative two will permit the safe design of integral abutment bridges that are longer than those designed using alternative one.