Being a curious type, I have checked on their progress from time to time and am still puzzled as to what their mission was/is.
After cutting through the pavement, the debris was removed, leaving a neatly cut foot-wide trench. What looked like reinforcing bars were installed then dirt was packed in to street level. [I've never saw any pipes, cables or anything else installed.] Not long after, the crew returned, dug-up the compacted dirt and poured in paving material. The same is being repeated on the opposite side of the street right now.
Our street isn't what I'd call heavily-travelled and there are usually few potholes at the end of winter, so why all the digging and filling? Surely D.C. isn't into "make-work" projects for contractors . . . Anybody know what's going on?