Bridge Pile Bent Number of Piles and X-Bracing System: Impact on Pushover Capacity as Scour Increases

A common design/construction procedure for highway bridges over marshes, small creeks, and streams is to have the bridge superstructure supported on pile bents. The focus of this article is to compare the relative lateral stiffness and pushover capacities of X-braced three-, four-, five-, and six-pile bents under combined gravity loadings and extreme flood/scour events. The relative performances of single- and two-story X-braced bents with and without a horizontal bracing strut at the bottom of the lower X-bracing were examined. Bent pushover capacities for the various combinations of the numbers of bent piles, bent heights, and X-bracing conditions previously described are presented in this paper.