slurry wall
A concrete wall that runs from the surface of the ground down to the bedrock. The most important consturction technique used in the Big Dig, it defines area where new high way tunnels will be built, and it is used as a mold for when more concrete is poured in.
Due to a defective slurry wall, the tunnel had to be closed down in case of flooding.
Slurry Wall
Any wall, toilet partition, or vertical surface containing a Glory Hole
I took a dump in the train station bathroom; and, lo and behold, I was surrounded by Slurry Walls