Raising By Application of Raise Borers
This technique can be used to drive a raise between 2 levels in the ground. Using this technique, Raises have been drilled successfully even in poor ground where the soil condition is not very good. A circular shape is obtained from this technique. In this technique, the machine is set up at the top and drills a hole of 225 to 250 mm diameter, to get to the lower level. After that a large reamer bit is put on at the bottom of the drill rod and then it reams up the raise.
We can execute the reverse procedure by the machine; however, this option is not very popular.
Raise borers can drive in soft ground and hard ground, and such units are useful to drive raises and shafts up to 6 m diameter,
This method has the advantages like, faster rates, better safety for working crews and least disturbance to the rock structure.
By using this method the holes by the following properties is driven before: Shaft length, 1000 m, Diameter .6 to 6 m (R. Tatia 2005)
Famous quotes containing the words raise, raising and/or application:
“We do not raise our children alone.... Our children are also raised by every peer, institution, and family with which they come in contact. Yet parents today expect to be blamed for whatever results occur with their children, and they expect to do their parenting alone.”
—Richard Louv (20th century)
“the old palaces, the wallets of the tourists,
the Common Market or the smart cafés,
the boulevards in the graceful evening,
the cliff-hangers, the scientists,
and the little shops raising their prices
mean nothing to me.”
—Anne Sexton (19281974)
“Courage is resistance to fear, mastery of fearnot absence of fear. Except a creature be part coward it is not a compliment to say it is brave; it is merely a loose application of the word. Consider the flea!incomparably the bravest of all the creatures of God, if ignorance of fear were courage.”
—Mark Twain [Samuel Langhorne Clemens] (18351910)