Estimation of the Remaining Service Life of Culverts

Culvert pipes play an integral part in transportation infrastructure since they facilitate safe drainage. A loss of culvert integrity could result in temporary roadway closure and considerable rehabilitation/replacement costs or worse. In addition, the total collapse of a culvert could pose a major safety risk to motorists. Hence culverts should be routinely inspected and condition state determined to estimate the remaining service life of culverts to propose corrective actions so as to prevent costly culvert failures. The techniques are developed for estimating the remaining service life of five types of culverts: Brick/Clay, Concrete, Cast Iron, Corrugated Steel and Corrugated Aluminum. A five state Condition State model that is used to express the extent of the culvert deterioration, is coupled with a reliability analysis based upon the Weibull model to estimate the remaining service life of the culvert. The cumulative distribution function of failure is normalized by the design life in order to collapse the decay curve into a single curve for the five material types. Based on the inspection data it was concluded that the proposed theory could represent the culvert performance data for five different culvert material types used in New Jersey. The proposed theory represents a preliminary approach to estimation of remaining service life of culverts. Future research is expected to focus on field studies to obtain the necessary cost and performance parameters for deteriorating culvert pipes and to perform a statistical analysis of the sample.