Migration fracture quantitative and control of thick-hard roof in full-width working face with large mining height
LU Yangbo
YAN Shaohong
ZHOU Kunyou
ZHANG Zhi
WANG Yuanjie
Abstract：With the continuous increase in mining depth of the working face,the strata pressure manifestation in the large mining height working face with multi-thick hard roof strata be-comes increasingly severe.To improve the control effectiveness of multi-thick hard roof strata in such faces,this study takes the 30202 working face of Muduchaideng mine in Inner Mongo-lia as the engineering background.Through field measurements,theoretical analysis,and nu-merical simulations,the fracture patterns and quantitative characteristics of thick hard roof strata in full-width working face were investigated,revealing the mechanism of fracture quanti-tative characters of thick hard roof in full-width longwall face on strata pressure phenomena.The results show that,the fracture of thick hard roof strata in full-width working face with large mining height has the phenomenon of migration from the middle of the working face to both sides of the working face,and has the characteristics of dynamic migration and fracture.The fracture size of thick hard roof in the central area of the working face is smaller than that on both sides of the working face.The boundary conditions for roof fracturing in full-width working face were classified into three types,"two adjacent edges fixed,two adjacent edges free","two opposite edges simply supported,one edge fixed,and one edge free","one edge fixed,one edge simply supported,and two adjacent edges free".Based on these classifica-tions,a boundary structural mechanics model for thick hard roof strata in full-width working face was established.Calculations revealed the fracture spacing and block quantities during se-quential fracturing from the central zone to the ends.A quantitative fracturing model for multi-thick hard roof strata was subsequently developed.Guided by the zonal fracturing char-acteristics and quantitative parameters,a collaborative control method combining"roof strip pre-splitting+regional hydraulic support management"was proposed.This approach signifi-cantly improved coal wall and roof control effectiveness at the 30202 working face.
Keywords：full-width working facethick hard roof stratamigration fracturestrong mine pressureroof control
Publication Date：2025-07-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：16( 754-769 )