Decision-Making Guidance for Culvert Rehabilitation and Replacement Using Trenchless Techniques

Culverts which are typically located under roadways and embankments for the passage of water are designed to support the super-imposed earth and live loads from passenger vehicle and trucks as well as the internal hydraulic loading from the stream flow. Many of the existing culverts in the U.S. are in a deteriorated state having reached the end of their useful design life, making them vulnerable to failures with potentially catastrophic consequences. Traditionally, deteriorated culverts have been replaced by the conventional open-cut construction method. Due to higher costs, adverse environmental and societal impacts associated with open-cut method, particularly in high population and busy roadways, transportation agencies are increasingly looking to adopt trenchless techniques for addressing their culvert problems. This paper reviews several trenchless rehabilitation and replacement techniques investigating their suitability to address different defects, and their compatibility with various host pipe materials and diameters. With focus on reinforced concrete pipe (RCP), corrugated metal pipe (CMP) and high density polyethylene (HDPE) culvert materials, easy-to-use decision-making flowcharts are presented in this paper. State transportation agencies, U.S. Forestry Service and other local government agencies that manage culvert infrastructure will benefit from this paper.