Distribution of wheel loads on bridge girders

This paper is concerned with the analysis of simply supported concrete bridges composed of main girders, having cross sections in the form of a T or an I, interconnected by cross girders. A simple empirical formula is presented for the distribution of wheel loads between the main girders. The formula is based on the computer analysis of a wide range of bridges idealized as a grid. The empirical formula and the computer results show good correlation.The formula presented is intended for use in bridge design and is suggested to replace equations in current American and Canadian specifications for highway bridges (AASHTO 1973 and CSA S6-1974), which lead in most cases to overly conservative designs.