Title of article :
On-Bottom Stability Design of Submarine Pipelines – A Probabilistic Approach
Author/Authors :
Amlashi, Hadi Schlumberger - Oslo, Norway
Abstract :
Un-trenched submarine pipelines will experience the wave and current loads
during their design lifetime which potentially tend to destabilize the pipeline
both horizontally and vertically. These forces are resisted by the interaction of
the pipe with the surrounding soil. Due to the uncertainties involved in the
waves, currents and soil conditions, there will be a complex interaction
between the wave/current, pipeline and seabed that needs to be properly
accounted for. The design of submarine pipelines against excessive
displacements due to hydrodynamic loads (DNV-RP-F109) is defined as a
Serviceability Limit State (SLS) with the target safety levels as given in DNVOS-
F101 (2013). In this paper, uncertainties associated with the on-bottom
stability design of submarine pipelines are investigated. Monte Carlo
Simulations (MCS) are performed as the basis for the probabilistic assessment
of the lateral stability of the pipeline located on the seabed. Application of the
method is illustrated through case studies varying several design parameters to
illustrate the importance of each design parameter for exceeding a given
threshold of the SLS criterion. Uncertainties in the significant wave height and
spectral peak period are found to be important parameters in describing the
Utilization Ratio (UR) distribution. Type of the soil has also an impact on the
distribution of UR, i.e. how the passive soil resistance in the pipe-soil
interaction model is accounted for. Therefore, the definition of characteristic
values of both loads and resistance variables are important for the UR.
Keywords :
Submarine pipelines , On-bottom Lateral Stability , Serviceability Limit State (SLS) , DNV-OS-F101 , DNV-RP-F109 , Monte Carlo Simulation (MCS) , Wave , Current , Soil Passive Resistance
Journal title :
Astroparticle Physics