Ultimate Strength of Skew RC Box Girder Bridge

Analytical and experimental results obtained in a study of a large-scale 45° skew two span four cell reinforced concrete box girder bridge model are presented. The model, which was a 1:2.82 scale replica of a typical California highway system prototype, had overall dimensions of 72 ft (21 m) long by 12 ft (3.7 m) wide, with two spans and a skew center bent diaphragm. Experimental and theoretical results are considered for reactions, steel and concrete strains, deflections, and moments due to conditioning overloads producing stress values as high as 2.5 times the nominal design stress. The loading to failure is described in detail. The ultimate strength behavior is examined on the basis of postulated collapse mechanisms and the bridge is observed to possess an excellent overload capacity.