https://1000southmichigan.com/blog/1...uction-update/
1000M CONSTRUCTION UPDATE
14 JANUARY 2020
CAISSONS NEARING COMPLETION
In December, the team was beginning the process of placing caissons across the construction site. Now, 34 of those 55 caissons are finished.
The caissons for the site fall into two categories: bell caissons and rock-socketed caissons. The geometry of all caissons is that they’re essentially large cylinders that sit on bedrock and support the foundation of the building. On one hand, bell caissons are markedly wider towards their bottom, and sit perched on the bedrock itself, meaning that there’s no requirement to core into the rock to stabilize bell caissons. Meanwhile, rock-socketed caissons require coring into the bedrock, and therefore need more force to get to the required depth (one foot deep into the bedrock), and take longer to install. Installation of all bell caissons is complete, and the team now turns their focus to finishing up the rock-socketed caissons.
With this accelerated schedule, all caisson work is slated for completion in early February.
NEXT STEPS: INSTALLING THE FOUNDATION
In last month’s update, we shared that the team was preparing to install the building foundation by removing the underground tanks discovered at 1000M’s site. With the site cleared, full excavation for the foundation, lasting 4-5 weeks, will begin after caisson completion.
Next steps will require reinforcing the rebar and formwork, installing underground utilities, doing site civil work and grading the ground, lasting about 6 weeks. In late March, the team will then pour an 11-foot thick slab foundation, serving as the full building footprint.
Construction will begin to go vertical in April and May; that’s when we’ll begin to see the tower take form.