Bridges

Corrugated metal culverts are a low capital cost option for drainage and grade separation structures. Large numbers of corrugated metal culverts installed around Australia over the last century now require effective strategies to manage them as they are both deteriorating and being exposed to increasing traffic loads. A number of recent failures of corrugated metal culverts have occurred, and sadly, five people drowned when a culvert collapsed on the Old Pacific Highway near Somersby, NSW in 2007. Consequently, authorities and the bridge engineering profession are on notice to manage better the thousands of Australian corrugated metal culverts. This paper considers the rehabilitation of deteriorated corrugated metal culverts using plastic liners, spirally wound and grouted into existing culverts. This process, which extends culvert life without the costly disruption of road closures, was originally developed as an aid to sewer rehabilitation, but has been trialled in several states to rehabilitate culverts. Observations drawn from case studies and soil-structure interaction finite element analyses point to significant differences in behaviour between flexible buried culverts and the culvert once it has been rehabilitated using a grouted liner. This highlights the need for a rehabilitation design procedure that is consistent with the behaviour of grouted liners rather than flexible buried culverts.