Use of polymer Geogrid reinforcement in the foundations of ground supported tanks for control of differential settlement
A paper by Sam Bhat, Jimmy Thomas, and Ron Skrobutan
This paper presents a case study wherein compacted granular foundation pads reinforced with polymeric geogrid were used to support pre-fabricated water storage tanks at a site in northern Manitoba, Canada. The subsurface strata at the site comprised thin layers of peat and silt underlain by sand and silt. Significant amounts of delayed settlements due to consolidation of silt and degradation of permafrost were anticipated. The differential settlements could be controlled by reinforcing the granular pad with polymer geogrids. The geogrid reinforced soil raft was to provide an environmentally friendly design as to reduce the permanent construction impact on the Keewatinoow land region. The foundation system avoids the use of large piles and concrete slabs. This allows for the easy dismantling of the foundation system and the construction site return to its natural state, after the short-term needs of the project have expired. The project consultants evaluated various alternatives for providing a safe, serviceable and environmentally friendly foundation for the tanks. The Horizontal Foundation Mat System turned out to be the simplest and most economical foundation solution. Initial observations indicate the performance of the system to be satisfactory and periodic monitoring of settlements will be carried out.