Performance Evaluation of Jointless Bridges

Abstract

A recent trend in bridge design has been toward the elimination of joints and bearings in the bridge superstructure. Joints and bearings are expensive in both initial and maintenance costs and can get filled with debris, freeze up, and fail in their task to allow expansion and contraction of the superstructure. They are also a “weak link” that can allow deicing chemicals to seep down and corrode bearings and support components. Because the behavior is unknown and designs are cumbersome, jointless bridges are not widely used despite their enormous benefits. There are no standardized design procedures for these bridges, only a list of specifications and design recommendations are available. The objective of this research on jointless bridges conducted at the Constructed Facilities Center-West Virginia University is to study the behavior of jointless bridges supported on piles and spread footings and subjected to varying load conditions. In addition, time-dependent material properties have also been incorporated in this study. In this paper, the following items are presented: (1) synthesized analytical data that aids in understanding the performance under varying load combinations; (2) effects of primary versus secondary loads, boundary conditions, and system flexibility on induced stresses at various bridge locations; and (3) field testing and monitoring results of a jointless bridge in the state of West Virginia. Based on analytical and experimental results, conclusions are drawn in terms of design alternations.