Forensic investigation of pavement failures

Abstract

Forensic engineering can be defined as the application of the engineering sciences to the investigation of failures or other performance problems, with a focus on uncovering causes so that improved facilities can be engineered. The investigation of road pavement failures can be done in a systematic manner using the principles of forensic engineering. The methodology developed in this project has been based on similar work previously conducted in various locations, mainly in Australia and the United States. The focus of this project is on creating a systematic, and yet simple and easy to understand guide that is flexible enough for use in a variety of situations. The investigation methodology developed was trialled for several pavement failures in Southern District of the Queensland Department of Main Roads, to evaluate the effectiveness of the method for everyday practical use. It was found that the method was good as a general guide, particularly for people with limited experience in the area of pavements and road engineering. The expertise of the investigator is however an important factor in correctly diagnosing the pavement failure cause and determining the appropriate rehabilitation treatment, and so the use of experienced personnel would generally be expected to lead to a better diagnosis. The study showed that for most pavement failures it is necessary to carry out some form of materials sampling and testing, if conclusive evidence regarding the failure cause is to be found. Otherwise, interpretation of the limited data available can be difficult, or even misleading, resulting in improper conclusion being made regarding the failure cause. The pavement failure investigation methodology developed in this project can serve as a useful guide for the investigation of pavement failures. The method, combined with the experience of the investigator and adequate materials investigation, will help to ensure that the cause of a pavement failure can be reliably determined.