Study and application of reasonable grouting pressure for "two-plugging and one-grouting" in bedding pressure-measuring boreholes based on numerical simulation
HAN Yuxuan
CHEN Xuexi
HU Jiaying
REN Qiangqiang
Abstract：Gas pressure measurement is a critical technical means for the prevention and control of gas disas-ters in coal mines.When cross-layer drilling conditions are unavailable,gas pressure must be determined through in-seam drilling,wherein grouting pressure significantly influences sealing quality and consequently measurement accuracy.This study therefore investigates reasonable grouting pressure to address the challenge of precise gas pressure measurement in in-seam boreholes.Theoretical analysis reveals that gas leakage chan-nels formed by pressure-relief fractures are the key factor affecting sealing effectiveness.A grouting seepage model is established based on Darcy's law,and COMSOL Multiphysics is employed to simulate slurry diffusion characteristics under grouting pressures ranging from 1.0 MPa to 7.0 MPa.Simulation results indicate that at 5.0 MPa grouting pressure,the slurry diffusion radius reaches approximately 44 cm,while increasing pressure to 7.0MPa yields merely a 1 cm increase(approximately a 2％increment).Based on the fitting curve correla-ting grouting pressure with diffusion radius,5.0MPa is identified as the reasonable grouting pressure.Taking the No.3 coal seam of a mine in Jincheng as the engineering background,six in-seam boreholes were con-structed in the transportation roadway of the 3701 working face to evaluate the pressure measurement perform-ance of the "two plugs and one injection" pressurized sealing under varying pressures.The findings demon-strate that a grouting pressure of 5.0 MPa effectively seals fractures in in-seam boreholes,enhances the accu-racy of gas pressure parameters,and provides significant engineering guidance for the prevention and control of coal mine gas disaster.
Keywords：coal and gas outburstin-seam boreholetwo plugs and one injectiongas pressurenumerical sim-ulationsurrounding rock deformation
Publication Date：2026-02-28
Online Publishing Date：2026-03-12(First online date of this platform, not the publication date of the document)
Pages：7( 85-91 )