The next step is to bring in the forms and encapsulate the steel armature with concrete.
“The next step is to bring in the forms and encapsulate the steel armature with concrete.”
There is concrete and rebar encapsulated inside the steel bollards, and it is set in a massive reinforced concrete foundation. The weekly report five a total of those two, and together they provide real strength.
Having the steel on the outside, protects against chisels, sledges and jackhammers.
Being able to see through makes tunnelers start from way back, and exposes breachers and climbers much earlier.