MODELING UNDERGROUND PIPE WITH PIPE STRESS ANALYSIS PROGRAM

摘要

The objective of this paper is the modeling of underground pipe in granular or sandy soil using a Pipe Stress Program for the evaluation of thermal, and pressure, to produce verifiable results. The use of a beam type pipe stress program to accurately perform stress analysis of underground piping can produce various results depending on the modeling. An updated presentation is available in B31.1 piping code with technical references, which gives some guidance in the use of pipe stress modeling. Modeling in a conservative way is difficult because what may be conservative to the underground piping may not be conservative at above ground transitions. An accurate methodology is required that produces verifiable results. Verification is accomplished by comparison with the B31.1 example problem and manual calculation using "Beam on Elastic Foundation" Also discussed are the effects of SIF's and flexibility factors used in above ground pipe and their application to underground piping. Ovalization of the piping is inhibited by the soil and the SIF's and Flexibility factors are affected (pg 231). Recommendations are given in the conclusion for the accurate modeling using beam type pipe stress analysis programs.