Accurate simultaneous casing drilling control method for composite rock mass

Abstract

The invention discloses an accurate simultaneous casing drilling control method for composite rock mass. The method comprises steps as follows: accurate setting-out of a drilling machine is performed, and the drilling machine and a bottom plate geologic body are firmly positioned through U-shaped ground screws; an ordinary down-the-hole hammer drilling rig which is 3-5 mm larger than the outer diameter of a simultaneous casing is adopted to drill through broken rock mass to a loose body interface; three drill pipe holes which are distributed in a 120-degree manner are drilled in the front section of a first drill pipe in the connection position with the ordinary down-the-hole hammer drilling rig, and the flowing state of air current nearby the ordinary down-the-hole hammer drilling rig is changed; as for the simultaneous casing for grouting on the loose body, the interval between casing body holes drilled in the simultaneous casing and the number of the casing body holes in the casing body section are limited. By means of the control method, accurate simultaneous casing drilling in the composite rock mass can be realized, the simultaneous casing drilling efficiency and accuracy are guaranteed, the accident rate of casing breakage in the composite rock mass is reduced, and the accident of jamming of a drilling tool in interfaces of rock mass with different qualities is effectively avoided.

Description

technical field [0001] The invention belongs to the fields of geotechnical engineering and mining engineering, and relates to a method for controlling drilling of rock mass, in particular to a method for controlling drilling of composite rock mass with precise follow-through pipe. Background technique [0002] In the field of geotechnical engineering and mining engineering, subject to the constraints of stratum conditions, in soft rock and loose strata, follow-up drilling technology is a leading technology to realize rapid drilling construction in complex and broken strata. At present, follow-up drilling process Basically, they drill directly from the loose body to the hard rock or only in the loose body, and the drilling construction accuracy is not high, basically there will be no stuck pipe accidents, and the drilling accuracy is not high. For composite rock masses whose quality alternately changes from hard rock→loose body→hard rock or more complex rock mass, the current...

AI Technical Summary

Problems solved by technology

For composite rock masses whose quality alternately changes from hard rock→loose body→hard rock or more complex rock mass, the current pipe drilling technology is very prone to pipe sticking accidents at the junction of hard rock and loose body. The accident rate of drilling reaches over 90%. At the same time, at the junction of hard rock and loose body, due to the influence of the density and strength of hard rock and loose body, the tracking pipe is prone to large-angle subsidence and deflection, resulting in a high probability of drilling Pipe breakage accidents, especially for follow-up pipes with grouting holes in the pipe body, the breakage rate is extremely high, and the accuracy of follow-up pipe drilling cannot be guaranteed

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