Slide 9
HDPE pipeline resting on the seabed are significantly subjected to the forces in both the horizontal and vertical directions due to buoyancy, wave and current loads. If a pipeline is not stable, it will then move vertically and horizontally. In the initial stages after finishing installation of HDPE pipeline before backfilling, the pipeline is exposed to the risk of these movements which may cause damage to pipeline.
The analysis of on-bottom stability was performed to keep the pipeline safely no movement based on DNV standards.
The concrete ballast weight was installed to keep pipeline stable during installation and operation against the environmental loading caused by waves and currents as well as floating.
I’d like to point out something I want to share during analysis. Vertical stability is not difficult to check considering concrete ballast, it is simple regardless the complex shape of ballast. However While the possibility lateral movement was checking, it was in trouble to determine the hydrodynamic coefficients such as drag and lifting due to its complex shape. Therefore concrete ballast weight was assumed to distribute evenly along the pipeline, then analysis was performed for equivalent concrete coating pipeline.

Slide 9

HDPE pipelines resting on the seabed are significantly subjected to the forces in both the horizontal and vertical directions due to buoyancy, wave and current loads. If a pipeline is not stable, it will then move vertically and horizontally. In the initial stages after finishing the installation of HDPE pipeline before backfilling, the pipeline is exposed to the risk of these movements which may cause damage to the pipeline.
The analysis of on-bottom stability was performed to keep the pipeline safely no movement based on DNV standards.
The concrete ballast weight was installed to keep pipeline stable during installation and operation against the environmental loading caused by waves and currents as well as floating.
I’d like to point out something I want to share during the analysis. Vertical stability is not difficult to check considering concrete ballast, it is simple regardless the complex shape of ballast. However, while the possibility lateral movement was being checked, it was in trouble to determine the hydrodynamic coefficients such as drag and lifting due to its complex shape. Therefore concrete ballast weight was assumed to distribute evenly along the pipeline, then analysis was performed for equivalent concrete coating pipeline.