No abstract

A significant portion of the current rehabilitation of the Bronx -Whitestone Bridge includes replacement of the roadway decking on the suspended span with closed-rib, steel orthotropic deck panels. Prior to the final design and production of the replacement panels, a full-scale laboratory fatigue test of a prototype panel was conducted at Lehigh University. The panel incorporated a diaphragm cutout and welded rib-to-diaphragm connection detail that was improved and refined with the aid of finite element models and experience gained from research conducted on orthotropic deck panels in the 1990s. Evaluations were made of the behavior and fatigue resistance of the orthotropic deck system and connections. Static and dynamic tests provided information on the two types of diaphragm plate splices and two types of bolted rib splices, determined the effectiveness of the rib wall stiffeners, and permitted a verification of a finite element model.

As part of an ongoing research program at Lehigh University, full-scale laboratory and field testing of a cantilevered section of an orthotropic bridge deck has been conducted. The laboratory research resulted in recommendations that were intended to improve the fatigue resistance of the welded ribto-diaphragm connection detail. Field testing of a section of the cantilevered orthotropic deck on the Williamsburg Bridge in New York City, NY, indicated that the laboratory test accurately reflected in service behavior and boundary conditions. Long-term remote monitoring of the deck also suggested that actual truck loads were greater than the standard truck loads assumed in the design specification. The results of the laboratory and field research presented in this paper indicate that modifications for the fatigue design of welded orthotropic deck elements may be required.