I posted here 6 weeks or so ago about a new underpass being planned for J10 of the M27.
The motorway was closed at 2000 on Christmas Eve, the road surface removed by 0300 on Christmas Day, and the 24000m^3 of soil where the underpass will go was excavated by early afternoon Boxing Day. Info at
It doesn't mention it on the above page, but evidently the "lubricant" used to help the underpass slide was a bentonite slurry.