Design of Ductile Iron Pipe on Supports
Typical design criteria involved with the design and/or installation of pipelines spanning waterways, highways, and railroads should be considered. Design procedures for Ductile iron pipe in normal underground service have been well established. In some situations, it is necessary or desirable to use supports at designated intervals along pipelines. Aboveground, supported pipe is needed to transport water and other fluids within treatment plants and buildings. Also, pipe on piers is utilized to cross natural or man-made objects. Sometimes, unstable soil conditions or other factors necessitate the installation of pipe on piers or pilings underground.
Pipe on Supports
DIPRA periodically receives requests from engineers and contractors concerning recommendations on the design and/or installation of pipelines spanning waterways, highways, and railroads. Because the variables involvedin such installations present numerous alternatives and challenges for designers and contractors, DIPRA does not provide recommendations and does not assume responsibility for design or installation practices on such projects.
DIPRA does, however, recognize the engineering complexities inherent to bridge crossing pipelines and offers information to assist those involved with this type of installation and to point out typical design criteria which should be considered for bridge crossings. Adaptation of the entire pipeline as a unit applied to a bridge structure involves close detail to many parameters in both structures.
Design procedures for Ductile iron pipe in normal underground service have been well established. The standard design considers hoop stresses in the pipe wall due to internal hydrostatic pressure as well as bending stresses and deflection in the pipe due to external loads of earth and traffic above the buried pipe.