Reliability functions for buried submarine pipelines in clay subjected to upheaval buckling

The reliability indices (β) of the pipe-soil system under upheaval phenomena were evaluated by means of directional simulations. Consequently, the reliability functions β-δ and β-H/D (ratio cover height over pipe diameter) were quantified. It was found that the inclusion of the lower-bound capacity by means of a left-censored distribution possibly increases β in comparison to the estimations using conventional distributions, the maximum increments observed are in the range of 22-34%.