Experimental study on the control of mine pressure and gas gover-nance in thick and hard roof by pre-blasting of slotted cartridge
QIAO Guodong
LIU Zegong
GAO Kui
ZHOU Yunquan
FU Shigui
Abstract：To address the issue of the high mineral pressure and high level drill holes'poor ex-traction which were due to the thick and hard roof,a research approach that integrates blasting similarity simulation testing with theoretical analysis was employed.This methodology is utilized to examine the macroscopic distribution pattern of cracks,the characteristics of damage,and the evolution of strain and stress within the target structure under the influence of both conventional blasting and slit packet blasting loads.Additionally,the blast weakening radi-us was quantitatively assessed.The results indicate significant disparities in the distribution of blasting-induced cracks on the model surfaces.Moreover,the quantitative characterization of rock blasting damage,employing the damage degree(D)and the wave velocity reduction rate(η),highlights that the effective damage range resulting from slotted cartridge blasting surpas-ses that of ordinary blasting.An analysis of dynamic strain signals reveals that the stress wave-front propagates faster in the slotting direction,exhibiting higher intensity.This,in turn,en-dows the rock layer with increased resilience against the explosive dynamic load,resulting in significantly greater peak strain and peak stress at the measurement point compared to ordinary blasting.Theoretical calculations further establish that the weakening radius of slotted cartridge blasting,measuring 21.8 meters,exceeds that of ordinary blasting,which stands at 16.5 me-ters.Consequently,the utilization of slotted cartridge blasting for thick and hard roof not only guarantees roadway stability but also proves to be more economically efficient.The research re-sults have certain guiding significance for solving the problem of integrated prevention and con-trol of mine pressure and upper corner gas under the condition of thick and hard roof.
Keywords：pre-blastingslotted cartridgethick and hard roofshigh level drillingmine pressure controlgas extraction
Publication Date：2024-03-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：13( 334-345,376 )