In Nunavut, at a gold mine site near Baker Lake, several operations buildings have encountered settlement and voiding issues related to their slab-on-grade foundations. Among these structures, the largest, measuring 100′ x 150′, experienced settlement between 0″ and 3″. Another building, sized at 100′ x 60′, exhibited settlement problems ranging from 0″ to 2″, along with voids ranging from 0″ to 5″. The third structure, measuring 97′ x 39′, faced voiding issues beneath the floor ranging from 0″ to 8″, necessitating lifts of approximately 0″ to 10″. These problems are attributed to permafrost degradation as the likely cause of the settlement and voiding conditions observed over time. When we say we go anywhere in Canada, we mean anywhere – even the far North.
A site visit was arranged, and a Poly-Mor Technician flew into Baker Lake taking elevation measurements on each of the building floors and foundations as well as drilling bore holes to determine the extent of voiding that may have taken place below the floor slabs. A formal proposal was presented to the client including costs of supply and installation of the appropriate foam system and costs of mobilization and demobilization. Upon formal completion of the agreement Poly-Mor arranged for the equipment, product, and manpower to be flown to the site. Poly-Mor’s experienced technicians undertook the void-filling and floor-lifting by drilling an array of 5/8” holes through the concrete floor, injecting Poly-Mor’s expanding resin systems to lift and align the settled floor structures back to their original elevation in most cases and to practical elevations a few locations. This relatively large job was completed within three days.
The job, as per usual, went extremely well and the client was most pleased as evidenced by the fact that the client has made arrangements for Poly-Mor to return to the site later this year to undertake further lifting and void-filling work. It is also noted that because of the high thermal characteristics of Poly-Mor’s resin systems, future floor settlement should be largely mitigated by the foam under the slab as where 3” of foam was placed the R-Value would be in the order of R-18.