Revision as of 13:22, 10 February 2009 by Tschid (talk | contribs) (Removed Metric units.)
Beveled pipe end treatment should be used on either corrugated metallic-coated steel pipes or corrugated polyethylene pipes 21 in. or less within the clear zone, as shown on Standard Plan 732.05. All beveled pipes use encasement. Corrugated metallic-coated steel pipe-arches are not beveled. In general, the bevel should not be flatter than 1V:6H nor should the skew exceed 15 degrees. If these controls are exceeded, special consideration is given to the use of headwalls, riprap, or slope pavement to stiffen the structure against uneven loading from the embankment and the dynamic forces of the water. Proposed designs for these conditions are submitted to the Support Center for approval.
All drainage pipes greater than 21 in. that fall within the clear zone are required to have safety slope end sections to eliminate the potential for vehicle snagging. End sections with two types of safety treatment for 1V:4H, 1V:6H and 1V:10H slopes are shown in Standard Plan 732.10. The 2B sheet should be used to indicate the slope of the end section and whether the end section is for a crossroad or parallel drainage structure.