Prediction of lateral distribution of vehicular live loads on bridges with unequally spaced girders

A more rational and accurate approach for predicting the lateral distribution of vehicular live loads on unequally spaced bridge girders is presented. Modeling of bridge deck and girders is discussed in detail. A better method of deriving the live-load distribution factor is introduced. Both maximum moment condition and maximum shear condition are considered in the derivation of the distribution factors. The derived distribution factors from the present study are compared with those determined from the simplified methods (empirical formulas) as adopted in the current bridge design code. Applicability of the code formulas is carefully examined, and advantages of the proposed refined approach are shown. The paper concludes with a number of real bridge examples.