Simplified Approach to Modelling Traffic Loads on Bridges

Abstract

Knowing realistic traffic loading is essential for optimised bridge assessment. A simplified approach to modelling the expected maximum traffic load effects, based on the convolution statistical method, has been proposed. Unlike the traditional method recommended by Moses and Verma (1987) it replaces the indirect calculation of characteristic load effects, through convoluted traffic loads (weights), with a procedure that convolutes the load effects (moments, forces) directly. The emphasis of the procedure is to evaluate accurately the tail of the load distribution histograms, the key factor for correct traffic load modelling, and then to apply a simple, yet sufficiently accurate procedure, applying cumulative distribution functions of the convoluted histograms, to forecast the realistic expected bending moments and shear forces of a bridge. Results of a concrete example, if compared to some alternative procedures, demonstrate that while the computing time is several times faster than for the traditional simulation methods, the results are comparable and conservative in most cases.