AN EXPERIMENTAL AND ANALYTICAL INVESTIGATION OF A HORIZONTALLY CURVED BOX-BEAM HIGHWAY BRIDGE MODEL

THE STRUCTURAL RESPONSE WAS INVESTIGATED OF A TYPICAL HORIZONTALLY CURVED BOX-BEAM HIGHWAY BRIDGE BY FABRICATING A PLEXIGLAS MODEL, APPLYING VARIOUS LOADING CONDITIONS, AND MEASURING THE CORRESPONDING STRAINS AT THE INNER AND OUTER SURFACES OF THE TOP DECK, BOTTOM FLANGE AND INNER AND OUTER WEBS AT SELECTED CROSS-SECTIONS. THESE STRAINS WERE CONVERTED TO TANGENTIAL AND RADIAL STRESSES TO DETERMINE THE STRESS DISTRIBUTION ACROSS A TRANSVERSE SECTION DUE TO THE APPLIED LOADING CONDITIONS. A CORRESPONDING STRESS DISTRIBUTION WAS ALSO FOUND BY MEANS OF AN APPROXIMATE ANALYTICAL SOLUTION USING THE FINITE ELEMENT METHOD OF ANALYSIS. A TYPICAL COMPARISON OF THE EXPERIMENTAL AND THEORETICAL STRESSES DUE TO THE SIMULATED DEAD LOAD AND UNIFORMLY DISTRIBUTED LOAD ON THE TOP DECK WERE PLOTTED FOR TOP AND BOTTOM FLANGES, AND INNER AND OUTER WEBS AT THE MIDSPAN CROSS-SECTION. THE EXPERIMENTAL STRESSES AT THE MIDSPAN, QUARTER-SPAN AND SUPPORT SECTIONS ARE TABULATED. A BRIEF DESCRIPTION IS PRESENTED OF FABRICATION, PREPARATION AND INSTRUMENTATION OF THE MODEL MEMBERS FOLLOWED BY SUPPLEMENTARY TESTS, MODEL TESTS, DISCUSSION OF RESULTS AND CONCLUSIONS. IT IS CONCLUDED THAT PLASTIC MODELS CAN BE SUCCESSFULLY USED TO INVESTIGATE THE STRUCTURAL RESPONSE OF CURVE, BOX-BEAM HIGHWAY BRIDGES WHEN SUBJECTED TO VARIOUS LOADING CONDITIONS. THE FINITE ELEMENT METHOD OF ANALYSIS CAN BE USED FOR OBTAINING RADIAL STRESS DISTRIBUTION ACROSS THE CROSS-SECTION OF A HORIZONTALLY CURVED BOX-BEAM HIGHWAY BRIDGE STRUCTURE. THE TANGENTIAL STRESSES, OBTAINED BY THE FINITE ELEMENT METHOD WERE NOT GOOD IN COMPARISON, BUT WERE PREDICTED WELL FOR DISTRIBUTION. THERE IS NEED THEN TO MODIFY THESE TANGENTIAL STRESSES SO AS TO CONFORM TO THE ACTUAL STRESSES OBTAINED EXPERIMENTALLY.