puits creusé par lançage

OBS: Dans les terrains très sablonneux, on peut être amené, pour faciliter le fonçage à avoir recours au lançage qui consiste à utiliser un jet d'eau sous pression.

CONT: Jetted wells, similar to drilled wells, are more common in sandy soils than in clay formations. A high-velocity stream of water is forced into the soil, then a jetting tool (point) is pushed into the loosened material to provide access for the well casing that follows. The casing of a jetted well often does not extend above the ground surface, a factor that both allows contaminants to enter the well and makes it difficult to later locate and inspect the well.