NEWSLETTER
Large Scale Instrumented Tests To Study Set-Up Around Suction Caissons
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NEWSLETTERLarge Scale Instrumented Tests To Study Set-Up Around Suction Caissons |
Fugro-McClelland Marine Geosciences, Inc. (Fugro) under the sponsorship of ExxonMobil, is co-funding a research program to study the set-up rate, and how the resulting axial pull-out capacity increases with time, of suction caissons, through a testing program of large scale instrumented caissons. The scope of the testing program is summarized below.
Three different caissons will be tested, so as to evaluate the effects of varying the diameter, wall thickness and length. The test caisson geometries and characteristics will be as follows:
| Caisson | Diameter D (ft) | Wall Thickness t (in.) | Length L (ft) | L/D Ratio | D/t Ratio |
| Small 1 | 5.5 | 3/8 | 22 | 4 | 176 |
| Small 2 | 5.5 | ¾ | 22 | 4 | 88 |
| Large | 11 | ¾ | 44 | 4 | 176 |
The caissons will be fully instrumented by Fugro Structural Monitoring, with differential pore pressure transducers, seafloor reference pressure transducers, differential pressure transducers, tilt sensors, plug level sensors, seafloor reference level sensors, temperature transducers, load cells. All data will be automatically acquired through redundant data loggers, powered by redundant power supplies.
The testing program will evaluate the magnitude of pore pressure increase due to caisson installation and the rate of pore pressure dissipation with time for the three caissons. Also, the program will allow the increase in pull-out capacity to be studied with time (set-up) of the three caissons. This will be done by measuring their pull-out capacity at different times after installation (viz. 1 hour, 4 hours, 8 hours, 24 hours, 30 days, 60 days and 120 days).
The program started around March 1, 2001, and is scheduled to run for a 12-month period. The program is offered for participation to others than ExxonMobil. For further details, please contact the project manager, Paul Stevenson. (pstevenson@fugro.com)
