关键词: 关键词：横向组合, 截面应力, 岩性异同, 弯扭变形

Abstract: Abstract: In the application of beam structure for the material cost savings, the horizontal combination of materials in building construction and bridge construction which is widely used, and even in coal production, the underground geological strata occurrence is very complex due to the crustal movement and the role of geological structure, many of them appear superimposed structure of the vertical strata. Here make a analysis for composite beam that composed of different components and horizontal combination then discuss the stress distribution characteristics of the composite beam cross-section in connection with the value of the adhesion force between rock beam layers to aim at the lack of research in drastic geological structure of vertical roof strata above the coal seam, Then the beam section stress formula is given for providing criteria to determine the elastic and plastic limit of the composite beam. Last, the beam under an external load prone to bending and torsion deformation is proved.

Key words: Keywords: horizontal combination, section stress, different rock lithology, bending and torsion deformation