nstability mechanism analysis of pressure-arch in coal mining feld under different seam dip angles
Keywords:
mining field, pressure-arch, instability mecha-nism, failure modesAbstract
In order to study the instability mechanism of the pres-
sure-arch in the mining field under different dip angles of the
coal seam, the structure mechanics model of the pressure-arch
in the mining field was built based on a practical engineer-
ing. The moment, shear, and axial force at any section of the
pressure-arch axis are obtained through the pressure-arch
axis equation. It is concluded that the entire instability of the
pressure-arch is caused by local damage and the failure mod-
els of local damage has three forms, namely tension-failure,
shear-failure and compression-failure through the comprehen-
sive analysis. The results show that with the increase of the
dip angle of the coal seam, the failure modes of the pressure-
arch change from compression-failure at the arch-waist and
shear-failure at the skewbacks to shear-failure at the vault and
tension-failure at the front of skewback. It is important to con-
trol the key parts, and actively regulate the mine pressure ac-
cording to the instability criterion of the pressure-arch in the
longwall mining field.