Behavior of Steel H-Piles Supporting Integral Abutments: Fid-Bau Portal

Behavior of Steel H-Piles Supporting Integral Abutments

Ingram, Earl E. / Burdette, Edwin G. / Goodpasture, David W. / Deatherage, J. Harold / Bennett, Richard M.

Steel H-piles are commonly used to support integral abutments. In the absence of expansion joints that allow the superstructure to expand and contract freely, piles supporting integral abutments are subjected to lateral displacement, horizontal shear, and bending moment. Calculating the true structural capacity of a horizontally displaced pile can be a daunting task. Engineers often design these piles according to AASHTO or AISC beam-column equations and neglect lateral support provided by surrounding soil. Results obtained from typical beam-column equations can be extremely conservative when applied to laterally displaced piles. Piles supporting integral abutments are not laterally loaded, but laterally displaced. The lateral displacement is a result of thermal expansion or contraction of the superstructure and all resulting forces are a function of pile stiffness, rotational restraint of the pile head, pile embedment depth, lateral displacement, and soil stiffness. Superstructure expansion and contraction are typically assumed to occur without significant resistance from the supporting piles. The piles are not capable of resisting the magnitude of force required to restrain the superstructure's massive cross-sectional area from longitudinal movement. Therefore, the magnitude of lateral displacement is assumed to be a function of the superstructure's coefficient of thermal expansion, length, and temperature range, but not a function of pile or soil stiffness.