GTA District School Board Floor Lift & Soil Stabilization
Challenge
Exterior walkway slabs sloping towards the building and directing water to the foundation is believed to be a contributing cause of the interior soils under the classroom floor consolidating and leading to settlement of the slab-on-grade floor. Obvious settlement and gaps under the baseboard are visible. This settlement caused an uneven floor surface for those using the space as well as the gap allowing insects to have access to the classroom.
Aside from the high cost and mess associated with floor replacement, it would have meant that the school board lost this classroom for a minimum of two – four weeks. Currently class size and usable space are at a premium with every school board. CCL’s Project Manager was brought in to review the situation and provide feedback to the school board maintenance officials. Reviewing the situation, our Project Manager proposed a series of injections to stabilize and increase load-bearing capacities of the soils in the problem area.
The school board officials reviewed the costs associated with traditional repairs of removing and re-pouring as well as the time needed to complete these repairs and found CCL’s proposal to be a fraction of the costs and all work associated with the project could be done in one day. The decision to go with CCL was an easy one!
Solution
1. Our installation team drilled and placed injection probes down to the 1m depth under the classroom floor.
2. Injections were carried out at the 1m depth to increase load-bearing strength of the problem soils. Approximately 90% of the floor lift needed was achieved from injecting at the 1m depth.
3. Additional injections were carried out directly under the floor slab to complete the lifting of the floor and to make sure all voids under the floor were filled and the slab was fully supported.
