Simulation of water infiltration below a damage in the pavement surface course

Abstract

The infiltration of rainwater is an important cause of pavement failure. Therefore, there is nowadays a special interest in studying water penetration through pavements. Experimental studies on this topic require costly or fragile sensors. As an alternative, we propose to use simulation. Firstly, the fundamentals of the proposed simulation methodology are presented (basically, the concern is to solve the Richards equation). The results of the characterization of a pavement from the Mexican Federal Roads Network are then given. Finally, we investigate the time from which the studied pavement may start to fail, if a hypothetical damage in its surface course is left to bad weather. Simulations show that the pavement may fail within a few days, if a pothole remains unfilled.

They also show that the pavement should not have serious problems caused by infiltration, if there is only one longitudinal crack in the middle part of the surface course (this is in disagreement with the literature, which suggests that infiltration through large cracks is always an important cause of pavement failure). The methodology exposed in this work can be used to analyze the design and maintenance program of other coated earth structures. In contrast to what is traditionnaly assumed when designing pavement-drainage systems, such a methodology takes into account the fact that pavement layers can be partially saturated.