01-21-2016, 12:45 PM
Seeing that the foundations for the bridge are pretty well completed, I can only assume that the dome is to allow for construction of the bridge span itself as clasher mentioned.
The need for a heated work environment also tells me the bridge is likely to be cast-in-place concrete as opposed to steel girders (Weber Street) or pre-cast concrete which wouldn't need to be installed in a controlled environment (also wouldn't be able to crane the pieces in through the dome. The remainder of the excavation and any retaining walls etc could be completed in the spring.
The need for a heated work environment also tells me the bridge is likely to be cast-in-place concrete as opposed to steel girders (Weber Street) or pre-cast concrete which wouldn't need to be installed in a controlled environment (also wouldn't be able to crane the pieces in through the dome. The remainder of the excavation and any retaining walls etc could be completed in the spring.