When crews prepared to drill the giant new cavity under Second Avenue, they first had to freeze the ground to about minus 20 degrees so as not to destabilize the buildings above as the boring machine cut through. For that, aluminum tubes were inserted from the street and a special chemical solution was poured into the ground and cooled by a refrigeration plant.
Interesting...
It must have been comforting for the building owners to know that this was all planned by government paid engineers and the work was being done by the lowest bidder.
What do they do with all the material that is excavated?
You mean NYC did some fracking?