... from 3.0 to 0.7, and no scour propagation is observed along the pipeline on the seabed for this range. For e/D = 0.5, local scour continuously expands in the spanwise direction of the pipeline, leading to the formation of free spans. Critical e/D value for the development of free spans lies between 0.5...

... with high temperatures and high pressures. As flowlines are not necessarily trenched and buried, an uneven seabed may cause significant free spans. Then, if the current and wave induced flow velocities are sufficient, the free spans may be exposed to cyclic loading and associated fatigue failure. One...

... 11 01 2011 On-bottom stability design of pipelines normally assumes that the pipeline rests on a flat seabed without any free spans. This paper presents on-bottom stability calculations accounting for the presence of free spans. It should be noted however that the calculations...

... 04 03 2009 Probabilistic methods have been used to develop the basis for free-span inspection of a gas pipeline system in the South China Sea. The objective of the probabilistic analysis was to study the probability of fatigue failure associated with postulated planar flaws in the HAZ...