Improved Design Approach for Buried Flexible Pipe

Abstract

Civil engineers have been analyzing buried flexible pipe structures using traditional theories such as the horizontal deflection formula (modified Iowa formula) and the prism load theory. The design based on these traditional theories may not correspond to the actual field pipe performance, due to the assumptions involved in the underlining methods. Within the last 10 years, new theories (vertical deflection formula, soil arching load theory, and others) were developed for the soil-pipe interaction problems. With these new theories available, a more realistic design/analysis is now possible for the flexible pipe structures. This paper first reviews the traditional design approach and points out their deficiencies. It then introduces the readers to the recent theoretical developments made in this area. The paper concludes its contents by going through a design example that incorporates the improved design approach.