The Weather and External Forces hazard (WEF) is considered in ASME B31.8 as a non-time-dependent hazard due to its random nature and the high uncertainty of the effects on pipelines given the occurrence of natural events, especially associated with hydro and geotechnical processes. Although there is a wide range of events associated with geological, hydrological and hydraulic conditions (among other things) that can affect a certain infrastructure, only a limited number of these geohazards can cause direct damage to hydrocarbon transportation infrastructure.
The identification and understanding of a ground failure process and its association with the susceptibility or physical fragility of the pipeline facing the potential adverse effects of a hazard event, allow to estimate the conditional probability of pipeline failure under loading stresses induced by the event and to estimate the actions needed to mitigate this hazard with methodologies ranging from approaches of structured expert knowledge to methods of structured analysis that incorporate incorporating subsurface investigation, detailed study of the results from terrain monitoring, pipeline and triggering agents through mechanical modeling.
This document presents a technical proposal for the management of geohazards which, due to the nature and characteristics of the instability processes and its relation with the activity of triggering agents, and the vulnerability of the pipeline, allow them to be analyzed as time dependent.
