During the winter of 1999, an offshore floating sea ice road was constructed west of Prudhoo Bay Alaska from a natural barrier island to Seal Island, a total distance of approximately 5 km or 3 miles. Construction took place between January 14, 1999 and March 21, 1999. Once the road was constructed, testing using a 150 nun (6 inch) borehole jack was conducted to monitor the strength characteristics of the ice into the spring. This testing provided information on the strength of ice for planning future ice supported construction work. Tests were conducted on March 17, April 16, May 6 and May 18. in 18 holes at 300 nun or 1 ft. intervals down the hole. Tests were also conducted in the natural ice for comparison. Pressure, displacement and time measurements enabled the determination of the stress and strain rates at which the tests were conducted. Selective coring showed good correlation of strength with brine volume was found to be quite good. Over the time frame, the upper half of the ice decreased in strength from an average of around 14 MPa or 2,000 psi to about half this value. In contrast, the ice in the lower half of the road increased somewhat in strength with its average strength being over 14 MPa or 2,000 psi. The strength in the bottom half of the ice compared quite favorably with that of the natural ice. As well as obtaining a significant body of unique engineering data on the strength of man-made ice, this work also demonstrated that these structures can be used safely wcU into the spring for construction activities.
During the winter of 1998/1999, an offshore floating sea ice road was constructed west of Prudhoe Bay Alaska from a natural barrier
