Simulation of Buried Natural Gas Pipelines and Determination of Optimum Safe Depth

Buried gas pipelines are vital assets of natural gas transportation system for every country. Therefore, investigation of their potential failure's roots is prominent. There are different causes for their failure among which imposed loads are the majority. In this study, considering soil as an elastoplastic material and deriving its constitution equation, a steel gas pipeline was modeled in its critical cross section where it passes under a road. Studying the behavior of the axial stress as maximum stress component and pipeline displacement under live and dead loads, a safe depth of 2 m was found so as to decrease and increase failure probability and safety factors, respectively. This height not only negates live loads, it alleviates the effect of dead loads.