Powder chemical injection apparatus for liquefaction-induced ground improvement applications

A multiple placement apparatus developed for powder chemical injection to improve partially or completely water-saturated soils with liquefaction potential under dynamic effects, the apparatus comprising:

• at least one auger injection pipe in the form of a hollow pipe and outer auger, comprising at least two threads at the bottom for drilling without the need for a conventional auger,
• at least one main shaft, the top of which is connected to a rotating equipment or drilling rig,
• at least one central inner pipe connected to the at least one auger injection pipe for transmitting a rotary motion from the rotating equipment or drilling rig to the at least one auger injection pipe via the at least one main shaft,
• a gear mechanism comprising multiple double sprockets or gears mounted on the at least one main shaft and the at least one central inner pipe, in contact with each other for transmitting the rotary motion to the at least one auger injection pipe,
• a shaft box with multiple openings for the at least one main shaft and the at least one central inner pipe to pass through and configured for enclosing the gear mechanism, ensuring a distance between the at least one auger injection pipe and for holding all parts together for the operation of the system,
• multiple cone bearings mounted in bearing shells, configured for fixing the at least one main shaft and the at least one central inner pipe to the shaft box for restricting movement in a vertical axis, preventing deflection of the at least one auger injection pipe and providing rotational movement only, and
• a powder chemical discharge unit comprising at least one discharge rod or discharge pipe configured to be inserted into the at least one auger injection pipe through the at least one central inner pipe, for allowing dry powder chemical to be injected to be discharged into a borehole.