The design of buried pipes, in terms of the allowable minimum and maximum cover heights, requires the use of both geotechnical and structural design procedures. The geotechnical procedure focuses on estimating the load on the pipe and the compressibility of the foundation soil. The focus of the structural design is choosing the correct cross-section details of the pipe under consideration. The uncertainties of the input parameters and installation procedures are significant. Because of that, the Load Resistance Factor Design (LRFD) method is considered to be suitable for the design of buried pipes. Furthermore, the interaction between the pipe structure and surrounding soil is better captured by implementing soil-structure interaction in a finite element numerical solution technique. The minimum cover height is highly dependent on the anticipated traffic load, whereas the maximum cover height is controlled by the section properties of the pipe and the installation type. The project focuses on the determination of the maximum cover heights for lock-seam CSP, HDPE, PVC, polypropylene, spiral bound steel, aluminum alloy, steel pipe lock seam and riveted, steel pipe and aluminum arch lock seam and riveted, non-reinforced concrete, ribbed and smooth wall polyethylene, smooth wall PVC, vitrified clay, structural plate steel or aluminum alloy pipe, and structural plate pipe arch steel, or aluminum alloy pipes. The calculations are done with the software CANDE, a 2D plane strain FEM code that is well-accepted for designing and analyzing buried pipes, that employs the LRFD method. Plane strain and beam elements are used for the soil and pipe, respectively, while interface elements are placed at the contact between the pipe and the surrounding soil. The Duncan-Selig model is employed for the soil, while the pipe is assumed to be elastic. Results of the numerical simulations for the maximum fill for each type and size of pipe are included in the form of tables and figures.

Report Number



buried pipes, maximum fill height, CANDE, 2D analysis

SPR Number


Performing Organization

Joint Transportation Research Program

Publisher Place

West Lafayette, IN

Date of this Version