SAFETY EVALUATION OF EXISTING PARTIALLY PRESTRESSED CONCRETE GIRDER BRIDGES

An efficient method for evaluating the safety of existing girder bridg es as a function of the load and resistance parameters is presented. T he bridge capacity is determined using a nonlinear finite element prog ram in terms of the truck load which is increased until structure coll apse occurs. It is determined that the reliability of fully prestresse d bridges is higher than that of partially prestressed bridges, with t he bridge system reliability is one-and-half to two times the girder r eliability index. It is also found that the system reliability is more senstive to accidental or local damage of the exterior girders than t he interior ones.