This report addresses the structural design of a buried piping system. This task is particularly interesting since it involves three engineering disciplines: geotechnical@ civil-structural and mechanical. Much work has been accomplished in this field since the turn of the century@ when the first formulas for soil loads on underground conduits were established. The engineer now has access to a number of codes@ standards and publications to calculate the load and capacity of buried piping systems. This report compiles and illustrates through practical applications@ various published methods and equations for evaluating the structural adequacy of buried piping systems. This report covers steel piping@ installed in a trench@ with pressurized flow and welded or segmented construction. The report addresses the following area: C Methods to calculate loads applied to buried pipe C Equations by which to estimate the pipe integrity under load C Application examples to assess the relative significance of loads Publication of this document - WRC Bulletin No. 425 was sponsored by the Pressure Vessel Research Council of the Welding Research Council.