FIELD: devices for strengthening and conditioning soft grounds. SUBSTANCE: proposed driven injector has hollow housing with outlet hole made in lower part and end piece with shank arranged in outlet hole of housing. Novelty is that shank of end is secured in housing by means of spring lock to provided separation of end piece from housing at required height of injecting under action of pressure of mud delivered into housing. Invention provides unobstructed getting of mud into ground owing to sharp reduction of resistance to flowing out of mud from housing through outlet hole and creates additional ground fractures in weak zones. EFFECT: improved strengthening of soil. 2 dwg