Bearing Capacity of Floating Ice Sheets under Short-Term Loads: Over-Sea-Ice Traverse from McMurdo Station to Marble Point.

摘要

The United States Antarctic Program s Antarctic Infrastructure and Logistics Program within the National Science Foundation s Division of Polar Programs operates an over-sea-ice traverse from McMurdo Station to routinely resupply Marble Point Camp. The traverse requires that heavy tractor trains travel over large segments of sea ice that can contain both narrow and wide leads (cracks). For this effort, we determined the ice thicknesses required for the resupply traverse to safely operate on both cracked and un-cracked (infinite) ice sheets during each of the four periods of sea-ice temperatures at McMurdo Station. Results presented in this report are valid for first-year sea ice only, and we recommend that the Marble Point Traverse stays clear of regions where there is an isolated multi-year floe embedded in first-year ice. Our analyses considered a 41,000 lb Caterpillar Challenger 95E tractor with attached Fassi crane towing a single 3000 gal. steel tank sled full of fuel (32,370 lb). Wide leads require use of a bridge, and thus we also consider the load case where a 9208 lb bridge is used to cross open leads up to 13 ft wide. We derived our results from a combination of finite element analysis (ice with leads) and closed-form solutions (semi-infinite and infinite ice sheets).