Abstract: A process for constructing a jet grouted subterranean column provided with reinforcement. A hole is drilled in the ground to the desired depth using a drill bit carried in a hollow drill rod to which a drill casing is detachably coupled. As the drilling proceeds, grout is applied through the drill rod and is injected sidewardly at high pressure to cut into and mix with the bore wall. The casing is detached from the drill rod and lowered to the bottom of the bore, with the grout filling the annular space between the casing and enlarged bore wall. After the drill rod has been withdrawn from the casing, the casing may be left in place and filled with grout such that the casing provides reinforcement for the resulting grout column. Additional reinforcing material may be inserted through the casing. In an alternative process carried out in accordance with the invention, a bore is drilled with a special drill rod and a sacrificial drill bit.

Abstract: A shroud which surrounds a submersible pump is lowered into a water well along with a column pipe which carries the pump. The pump is located below the top of a screen which provides a perforated portion of the well casing. The shroud has an open bottom end located below the pump. An inflatable bladder attached to the shroud can be inflated through an inflation hose extending to the surface. The shroud may be connected with the column pipe by radial arms which maintain an open flow path between the column pipe and shroud. Water which falls in the casing when the pumping level drops below the top of the screen is not subject to aeration from the surface because of the seal provided by the bladder. The shroud around the pump creates a vacuum effect which increases the well capacity.