Simple Method for Incorporating Lateral Wheel Wander in the Computation of Fatigue Damage in New Flexible Pavement Structures

Abstract

The lateral position of trucks wheels when they pass over the pavement is not the same for all trucks. This variation in the lateral position of truck wheels is called wheel wander, and it is generally assumed to follow a normal distribution. For pavement design purposes, it is assumed that the standard deviation of this normal distribution is 250 mm. The lateral wheel wander reduces the accumulation of damage in a given point inside the pavement structure and therefore prolongs the fatigue life of pavements. The lack of lateral wander causes stress concentrations and therefore increased damage and distresses to pavements. This paper describes a method for incorporating any distribution for lateral wheel wander in the estimation of damage in flexible pavement structures using matrix construction and multiplication. This method was applied for two different pavement structures and several standard deviations of wheel wander. The results show that the lateral wheel wander phenomenon decreases the induced fatigue damages in the pavement structures when compared to that caused by channelized traffic (no wander). The results also show that the effect of wheel wander on the induced fatigue damage is less in thicker pavement. The equivalent axle load factor between distributed and channelized lateral wheel wander were calculated to demonstrate the effect of different standard deviations of wheel wander on the induced fatigue damage.