Toronto The One | 328.4m | 91s | Mizrahi Developments | Foster + Partners

A mobile crane will be installed in the laneway next week.
They look like 6 x 6's posts bolted together is sets of 2's. I'm not sure what they're for though.
They typically spread the load of the mobile crane on the concrete slab. Since they have to get that crane in closer to the elevator core to install the glass, they may also use it to bridge the slab opening for the crane outrigger (extendable support).
I'm guessing that the full weight of the transfer slab was a bit too much for the existing two floors below to support and that the first pour here once cured will support the second pour.