DISTRIBUTION OF LOADS TO GIRDERS IN SLAB-AND-GIRDER BRIDGES: THEORETICAL ANALYSES AND THEIR RELATION TO FIELD TESTS

A PICTURE, BASED ON THEORETICAL ANALYSES, OF THE MANNER IN WHICH LOADS ON SLAB-AND-GIRDER HIGHWAY BRIDGES ARE DISTRIBUTED TO THE SUPPORTING GIRDERS IS PRESENTED. THE DISCUSSION IS RESTRICTED TO SIMPLE-SPAN, RIGHT BRIDGES CONSISTING OF A SLAB OF CONSTANT THICKNESS SUPPORTED ON FIVE GIRDERS, SPACED EQUIDISTANTLY, AND HAVING EQUAL FLEXURAL STIFFNESSES BUT NO TORSIONAL STIFFNESS. THE NUMEROUS VARIABLES INFLUENCING THE BEHAVIOR OF THIS TYPE OF STRUCTURE ARE LISTED, AND THE EFFECTS OF THE FOLLOWING ARE CONSIDERED IN DETAIL: (1) THE RELATIVE STIFFNESS OF GIRDERS AND SLAB; (2) THE RATIO OF GIRDER SPACING TO SPAN OF BRIDGE; (3) THE NUMBER AND ARRANGEMENT OF THE LOADS ON THE BRIDGE; AND (4) THE EFFECT OF DIAPHRAGMS, THEIR STIFFNESS, NUMBER, AND LOCATION ON THE STRUCTURE. PARTICULAR EMPHASIS IS PLACED ON THE RELATIVE MAGNITUDES OF THE MAXIMUM MOMENTS IN INTERIOR AND EXTERIOR GIRDERS. THE RELATIONSHIP BETWEEN THEORETICAL ANALYSES AND THE BEHAVIOR OF ACTUAL STRUCTURES IS ALSO CONSIDERED, AND THE PAPER CONCLUDES WITH A DISCUSSION OF THE MANNER IN WHICH THEORETICAL ANALYSES CAN BEST BE USED IN PLANNING FIELD TESTS ON SLAB-AND-GIRDER BRIDGES, AND IN INTERPRETING THE RESULTS OBTAINED. /AUTHOR/