According to the video, they are installing fiber optic cables that can be used to detect footsteps and tunneling.
A half mile in ten days, in that terrain, doing everything they are doing, isn't too shabby at all. Heck, it takes the state two to four weeks to simply repave a half mile of interstate.
Here in my neck of the woods, they needed to build a bridge to span a canal, everyone believed the it was going to be a simple bridge consisting of a pipe covered with dirt that would take maybe a month to complete, just like all other bridges along this same canal, instead they build a monstrosity like the one they build for mayor interstate roads, all concrete that took over a year to built and, now that is completed. Due to its design. only helps drivers going in one direction.
This bridge goes over a canal that may be 25' more or less, we all wonder who paid for this monstrosity and how much it cost. I guess is "Our taxpayer money at work"