Raise Boring

Raise boring machine, also called raise borer, is usually used in vertical drilling on hard formations such as mining. In raise boring system, the pilot hole is drilled down to a lower level. Once the pilot hole connects to the lower access level in the rock, the roller bit will be removed and replaced with raise boring reamer, and then raising-bore the hole. The cuttings fall by gravity into the chamber at the bottom of the hole, where they are mucked out using a LHD-type loader.

Raises up to 6 m in diameter and up to 1000 m in length are not uncommon.

Applications

• Mining Sector: Raise Boring is used for ventilation, transferring ore from one level to another, silos for storing rock, access of personnel or material underground, and the hoisting of rock and ore to surface.
• Civil sector: In urban infrastructure, Raise Boring is used to collect waste or flood water from streets and route it to an underground tunnel to dispose of, and access shafts and ventilation shafts required in underground metro and rail systems.
• Energy sector: these type of holes and shafts in Hydro Electric or Pump Storage plants as pressure shafts. In addition, it is used for access to underground nuclear storage facilities.

Advantages

• The equipment does the work therefore reducing the number of personnel required to operate the machinery, and removing them from any potential hazards.
• No explosives are used during Raise Boring which can be done in a continuous cycle.
• It is a fast and efficient way of excavating rock and very hard rock.
• It is a lower cost alternative in certain applications and scale when compared to alternative methods.
• Stable circular excavation is completed with no damage to the sides of the hole or shaft, ensuring better accuracy.
• The system can drill large diameter in long lengths at an angle between 45-90 degrees.