THE MARINE GROWTH SENSITIVITY STUDY (MGSS)
The structural benefits associated with marine growth control are dependent on the platform configuration, environmental loading, engineering practice and various other factors.
Studies have generally shown that hard fouling increase drag force and subsequently the overall wave force / hydrodynamic loading. However, there are no specific studies in quantifying the structural benefits of controlling marine growth on offshore platforms.
What are the direct structural benefits in controlling marine growth on offshore platforms?
With the aid of an international design house, IEV conducted a ‘Marine Growth Sensitivity Study’ (MGSS) to quantitatively establish the local and global structural benefits, namely base shear, axial load, fatigue life and reserved strength ratio (RSR), of controlling marine growth on offshore structures.
The MGSS was conducted for three typical jacket configurations, tripod, 4-legged jackets and 8-legged jackets; actual surveyed growth profiles attained from (respectively) Thailand, Vietnam and Indonesia, were considered in the study.
PILE AXIAL LOAD
For the 8-legged jacket, the pile axial load reduction range from 2% (with marine growth removal from first bay of the conductors) to 5% (with marine growth removal from the first bay of all members).
Should removal of growth be extended to the second bay, the fatigue life of the connections is enhanced even further; i.e. up to 110% and 180% respectively.
RESERVES STRENGTH RATIO IMPROVEMENT
1ST BAY MGR TRADE OFF BENEFITS