Presplit hole drilling method

Abstract

The invention discloses a presplit hole drilling method. The method comprises the steps that two vertical lines are erected right ahead of the vertical direction of a designed presplit line, the midpoint of a drill rod is aligned, and the azimuth angle of a drilling hole is controlled in a three-point one-line mode; and two shallow holes are drilled behind the presplit hole, supporting vertical columns are placed into the shallow holes, a transverse rod is transversely placed on the vertical columns to support a big arm of a drilling machine, and the big arm of the drilling machine is fixed to the transverse rod, so that the angle of the drill rod on the vertical line is measured and adjusted through a geological compass. By means of the presplit hole drilling method, the angle error of the presplit hole can be controlled within one degree, seismic explosive columns serve as explosives for presplitting, and a formed step is clean in slope surface and clear and flat in outline; the half-hole rate reaches 60% or above in a soft rock area and reaches 90% or above in a hard rock area; the slope surface unevenness degree is smaller than 15 cm; and the desired effect is achieved, and the side slope stability is ensured.

Description

technical field [0001] The invention relates to the field of open-pit mine blasting, in particular to a pre-split hole drilling method. Background technique [0002] Pre-splitting blasting is to arrange dense blastholes along the design excavation boundary, and initiate blasting before the main blasting area, so as to form a pre-crack between the blasting area and the reserved area, so as to reduce the damage of the main blasting to the retained rock mass and form a smooth profile surface. Blasting operations. Pre-splitting perforation is the most important part of pre-splitting blasting. At present, in terms of pre-splitting perforation, the types and models of drilling rigs used are different, and the drilling methods are also different; in 2004, the eighth project of China Water Resources and Hydropower Corporation Bureau Co., Ltd. modified the YQ-100B down-the-hole drilling rig. The method of pre-splitting and perforating by building the drilling rig bracket is the late...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a pre-splitting drilling method to solve the problem of difficult construction, low precision and slow operation speed in the pre-splitting operation of the down-the-hole drilling machine.

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