Tamarack Lodge, Traverse City, MI

The Tamarack Lodge is a five-story, multi-unit condominium on the east arm of Grand Traverse Bay. The site has loose, sandy soils underlain by soft lake marl at depths from about 10 feet to 40 feet below grade. In addition, the overall site grade was raised by about four feet. The combination of the weight of the proposed buildings and the weight of the imported fill created the potential for settlement of the sand and lake marl.

Gosling Czubak completed a soils exploration that identified the soil conditions and developed  a method to both mitigate the potential settlement and evaluate the strength of the lower soft lake marl soils. We conducted consolidation and other laboratory tests on the lake marl to determine its strength and settlement characteristics. Supplemental information and analysis included stress analyses to see how the weight of the building and the imported fill would affect the lower lake marls.

 To improve the density of the upper sandy soils, we recommended and provided observation for vibro-compaction. The outcome was a strong foundation for Phase I of the development. The remaining phases will be constructed in the future with the aid of the existing soils information gathered during the soils exploration.