Definition - What does Uncased bore mean?
An uncased bore is a borehole that has no pipe or lining. Since the hole is self-supporting, it offers no guarantees to drilling operators that it will remain intact. A borehole without casing can be a major safety hazard for workers.
It may be used as either a temporary or permanent solution in trenchless construction.
Trenchlesspedia explains Uncased bore
Construction sites are highly regulated to ensure safety. Reinforcing excavated drilling holes is one of the ways to ensure safety for workers. However, there are circumstances where an uncased bore is permitted in trenchless construction.
In the book “Trenchless Installation of Conduits Beneath Roadways,” author Tom Iseley discusses uncased boring. He says that “this practice results in an unsupported hole, and the unprotected augers rotating in the drive shaft create special hazards for workers.” If uncased [auger boring] is permitted, workers should limit its usage to soil conditions with sufficient stand-up time and short, small diameter bores.