Study on application of combinatorial key stratum theoryand parameters determining;

Based on the analyzing of parameter about combinatorial key stratum, the formulae of calculating the roof weighting step is given in this article.

Analysis of combinatorial key strata stability in shallow coal seam with thick loose bed;

In this paper, the mechanical model of combinatorial key strata is analyzed with the help of the method of catastrophe theory, and an expression of the total potential energy function for this system is derived by the cusp catastrophe model.

According to the deep analysis on the formation mechanism of compound rock strata, the mechanical condition of compound rock strata formation and the related formula are obtained to build up the differentiate method of the compound key strata in the coal face strata and the corresponding differentiate program is made.

Using the finite element method to do numerical simulation on the dynamic developmental rule of the abscission layer under the compound key strata, it is discovered that the developmental space rule of abscission layer under the compound key strata presents two phases; the abscission layer before the compound key strata s first collapse mostly distributing in the central section o.