六、操作技术 1.钻压的保持根据岩石破碎的弹性理论,在一定预压下岩石冲击破碎强度要低50～80%左右。有预压的潜孔锤钻进比无预压的钢绳冲击钻进,其效率要高3～5倍以上,所以潜孔锤钻进时,需要足够的钻压,使钻头与孔底岩石紧密接触。在钻孔直径为152.4毫米(6英寸)时, Sixth, operating techniques 1 to maintain the weight-bit According to the rock fragmentation of the elastic theory, a certain pre-press rock crushing strength is lower about 50 to 80%. Pre-pressured down-the-hole hammer drilling than without prestressed steel rope impact drilling, the efficiency is 3 to 5 times higher, so DTH hammer drilling, drilling pressure needs to be sufficient to make the drill bit and bottom of the rock Close contact. At a bore diameter of 152.4 millimeters (6 inches)