A method to model the nonlinear behavior of bridges using a grillage d
iscretization is proposed. A modified stiffness matrix is used to acco
unt for material nonlinearity. The method accounts for material nonlin
earities due to bending and shearing stresses. A program is developed
to perform an incremental analysis of bridges subjected to vehicular l
oads. The validity of the model and program is verified by comparing t
o the results of full-scale field tests and published analytical resul
ts. Copyright (C) 1996 Elsevier Science Ltd.