Structural Design of Buried Culverts with Slotted Joints

Abstract

Circumferentially slotted bolt hole connections, a new concept for corrugated metal culverts, have proven to be effective in reducing thrust stress (ring compression) in deep embankment installations. Pragmatically, this means that slotted‐joint culverts can be buried deeper than standard‐joint culverts or lighter gage metal can be used. However, because of the present lack of design tables and guidelines, this economical innovation has far from researched its full application potential. In an attempt to fill this need, this paper offers a complete design method employing an experimentally verified culvert‐joint‐soil system model with analytical solutions along with a set of realistic design criterion. The design method is used to generate a sequence of design tables for 6×2‐in. corrugated steel pipes with slotted joints, in which the tables specify the maximum allowable fill height cover as a function of pipe diameter, wall thickness (gage), and soil stiffness. It is concluded that, even though the design method is conservative, the slotted‐joint pipes can, in some cases, sustain fill heights more than twice that of standard pipes if high structural quality soil is used.