Evaluation of Integral Abutments

Abstract

An integral bridge is a single or multiple-span structure that is cast monolithically to its abutments. Stub abutments supported on a single row of vertical piles create a flexible connection that can accommodate the longitudinal displacements of the superstructure. The primary purpose of using integral abutments is the elimination of deck-movement joints and bearings that have been found expensive to maintain. This research project is centered on the evaluation of integral abutments as a design alternative to the use of bearings in medium-length highway bridges. It includes: 1) an extensive literature search; 2) the instrumentation of Scotch Road Bridge in Trenton, N.J. to obtain strain data on the piles, displacement and rotation data on the abutment, soil-pressure data on the abutments and the MSE wall, and strain data on deck connection; and 3) a finite element model of the system. The end result is the recommended design procedure for integral abutments of highway bridges. Integral abutments have been found to be a safe alternative design. A step-by-step design procedure for piles to withstand the horizontal thermal loading is included.