Caisson structures in the Beaufort Sea 1982-1990 : Characteristics, instrumentation and ice loads

• Main Authors: Timco, G. W., Johnston, M. E.
• Format: Report
• Language: English
• Published: National Research Council Canada 2002
• Subjects: Beaufort Sea; Sea ice
• Online Access: https://dx.doi.org/10.4224/12328162; https://nrc-publications.canada.ca/eng/view/object/?id=fa717e43-d8c5-44bb-af82-fb1040ed783c

This report presents a comprehensive overview of the characteristics, instrumentation and measured ice loads on the caisson structures that were used for exploratory drilling in the Canadian Beaufort Sea in the 1970s and 1980s. Details are presented on the Tarsiut Caissons, the Single Steel Drilling Caisson (SSDC), the Caisson Retained Island (CRI), and the Molikpaq. Details on the ice-load measuring instrumentation are presented for each of the drill sites where an ice-load measurement program took place. The global loads on the structures are presented as a Line Load (Global Load per width of the structure) and the Global Pressure (Line Load per ice thickness). Global loads are shown to be a function of the ice macrostructure (level first-year sea ice, multi-year ice, firstyear ridges, hummock fields, isolated floes). The analysis shows that there is a general increase in the Line Load with increasing ice thickness. The data show considerable scatter. Much of the scatter can be explained by examining the failure mode of the ice during the interaction process. The most significant result of the analysis shows that the maximum Global Pressure measured for all types of ice loading events never exceeded 2 MN/m².