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A Key article to learn " Method of Tunneling in Soft Rock " providing easy access to learn     Classification of  Method of tunneling in soft rock  1)Hard rock or fully self supporting 2)Soft soils  requiring temporary support during and after construction. Forepoling Method      Sequence of operation The shaft is sunk from surface to the grade level and properly protected with timber sheeting A wooden bent properly braced is setup a few inches from sheeting Small holes at close interval are drilled through the sheeting to facilitate section being cutout.The pattern of holes are 3 inches apart above the cap and other lines of holes below the cap A peice of sheeting is cutout along the top lines of the holes Forepoles or spiles consists of planks with wedge end are entered one at a time and driven through cut,into the ground for half their lengths with an upward inclination of 2 inch per foot. After all the roof and part of side spiles are driven to half their length a timber