I’m an engineer and am currious on how that’s done. Another thing that puzzles me is if the pipe passes through a water table what forms the cement against the pipe there if you know what I mean. It seems to me that the cement would flow into the water table. Thanks for any help.
They use coiled tubing that does, in fact, bend. The cement sets up to form a solid, adhesive bond, and fills the annulus between the tube and the hole diameter.
Yes, the pipe will bend to some extent. The 90 degree turn is often made over several hundred feet. There isn't an actual right angle. They also employ joints where needed to allow for tighter turns.
Cement hardens through a chemical reaction with water. In essence, it won't flow and water is what helps set the concrete. You have to remember that a water table is a water saturated rock and isn't an underground river where fluids flow freely and as quickly as possible.