Evaluation of dynamic vehicle load on bridge decks

Abstract

Developed herein is a spectral approach for evaluating the dynamic vehicle load due to the passage of a vehicle moving at constant speed along a rough bridge surface. Based on the approach, a simple closed-form solution for predicting the variation of dynamic vehicle load on a bridge deck is derived. Numerical examples of the application of the solution to a simply-supported bridge are presented. Four different classes of pavement roughness (including: very good, good, average, and poor pavements) and three different vehicle speeds (speeds of 60, 100, and 140 km/h) are used in numerical analysis. The Dynamic Load Coefficient (DLC), a parameter used to characterize the magnitude of dynamic vehicle load, is estimated. The effects of vehicle speed and pavement roughness on the variation of dynamic vehicle load are investigated. It is concluded that if the effect of engine motion on vehicle vibration is disregarded, both the DLC and standard deviation of dynamic vehicle load are proportional to the square root of the pavement roughness coefficient S(no) for a specified vehicle speed.