Application

Eriksson Pipe designs buried reinforced concrete circular and horizontal elliptical pipe culverts in accordance with AASHTO earth and live load requirements and AASHTO reinforcing design requirements.  Railroad live load requirements are computed in accordance with the American Railway Maintenance and  Engineering Association (AREMA) Manual for Railway Engineering (Reference 5).   The program  is general and can  be used to  design  any circular or horizontal  elliptical  pipe.   Parameters that  may be specified· by the  user include the following:

• Pipe Geometry - diameter for circular pipe, or for horizontal elliptical pipe, elliptical radii, horizontal offset, and vertical offset, and wall thickness. 

• Loading Data – depth of fill over crown of pipe, density of fill, load system, soil structure interaction factor, depth of internal fluid, internal pressure (circular pipe only), density of fluid, truck loading, and vertical and lateral surcharge loads.  For three edge bearing design the user specifies the D-load.

• Material Properties – reinforcing tensile yield strength, concrete compressive strength and concrete density.

• Design Data – load factors, concrete cover over inner and outer reinforcement, reinforcing diameters, reinforcing spacing, reinforcing type and layout, crack control factor, shear process factor and radial tension process factor.

Only the pipe geometry, depth of fill and load system must be specified by the user.  If no values are specified for the remaining parameters, the computer program uses standard default values.  The default values may be easily changed to suit the user's particular needs.

The program has the following limitations:

• The range of diameters (span for elliptical pipe) permitted is 12 to 144 inches.

• The specified bedding angle must be between 10 and 180 degrees.

• Only circumferential reinforcement is designed.

• Wall thicknesses must be selected by the designer.

• Internal pressure is limited to 50ft of head (21.7 psi).

The in ground behavior of pipe culverts is dependent on the methods and materials used in the installation of the pipe.  While Eriksson Pipe provides a powerful tool for analyzing and designing reinforced concrete pipe culverts, it is the responsibility of the user and the installation designer to assure that assumptions made during the analysis and design phase can be and are met during the installation phase of the project.