Sobko Y. Experimental and theoretical analysis of stress-strained state of reconstructed beam-and-slab highway bridge spans

The dissertation is devoted to the problem of stress-strained state of RC reconstructed highway tee bridge spans and creating effective structural solutions of its widening and recommendation for computation and engineering calculation methodology on vehicle loading. In situ study of diaphragm tee bridge and models test of diaphragmless tee bridge before and after widening by superimposed ribbed plate and attached elements were carried out. The new test data of stress-strained state and nonlinear experimental bending moments from those data was obtained. The algorithm of non-linear computation with real stiffness in FEM elastic models and engineering two step methodology of solving the nonlinear deformability problem are proposed. The values of bending moments derived from those propositions were performed; good coinciding with experimental ones was obtained. It was established that strength reserve of diaphragm tee bridges are: 25 % before and 32 % after widening by RC superimposed plate; 14.5 % befor e and 22 % after widening of diaphragmless tee bridges. The results of the work have found an industrial implementation in the experimental reconstruction of bridges in Ukraine, Russia, Kazakhstan and in the some items of "Highway Bridge Reconstruction Code" BCH 51-88.