Ready for concrete — Here the bottom has already been poured with the steel embedded.  Now the crews have inflated the form, and will begin to spray shotcrete on the outside.  This could just as easily be done by hand, and in many places is more efficient.

Ready for concrete — Here the bottom has already been poured with the steel embedded. Now the crews have inflated the form, and will begin to spray shotcrete on the outside. This could just as easily be done by hand, and in many places is more efficient.