Toward best practices for construction and maintenance of through-grade culverts to mitigate pavement roughness

Culverts are used to preserve pavement embankments by draining water from the structures. However pavement roughness caused by excessive bumps, sags, and depressions at a culvert location are signs of failure or improper construction. The surface roughness at a culvert location can be caused by inadequate compaction of granular base material, erosion of the backfill or supporting materials, and (or) differential frost heaving. Pavement roughness can adversely affect ride quality and create potentially unsafe driving conditions. The objective of this study is to recommend construction and maintenance solutions to mitigate bumps, sags, and depressions at through-grade culverts on highways in Manitoba. The study consists of a review of the state of the art practices in culvert construction and maintenance; a survey questionnaire to obtain construction and performance history of through-grade culverts in Manitoba; and a forensic investigation and case study analysis of failed culverts with excessive bump, dip...