Selection of Reasonable Section Heights During Top-coal Caving to Steep Seams
SHAO Xiao-ping
ZHANG Hong-xiang
SHI Ping-wu
Abstract：Estimation of reasonable face-section heights during horizontal top-coal caving to steep seams was studied. Bare roof strata were modeled as simplified, trilateral, clamped, ob-lique, rectangular thin plates subject to lateral and longitudinal loads. The five main factors af-fecting section height are: the length of the strata plate; the length of the incline; the angle of the strata; the load from the overburden; and, the Poisson ratio of the rock. The standard for choosing the limit to the section height is that the strata plate don't break before coal and re-fuse in the gob area can move down the trough shaped gob after the overlying coal has been ex-cavated. Reasonable section heights may be divided into three categories. First, for a seam in-clination of 45° to 55°, about 29 meters. Second, for inclinations of 55° to 75° a height in the range of 51 meters. And, third, for inclinations from 75 o to 90° the choice of mining technolo-gy and equipment is more important than the choice of section height. This study will help pre-vent the risk of large-scale roof collapse during production at the working face.
Keywords：horizontal section top-coal cavinglarge section heightratio of mining to lettingplate destructionreasonable section height
Publication Date：2009-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 544-548 )