ABSTRACT
Experimental prototype is 11# and 12# merged seams and 14-2# coal seam in coal group 410 panel in Meiyukou coal mine, the spacing of coal seams is 3 m and extracted in downward mining sequence. The physical test is designed along the strike of the coal seams using the plane stress model and the model materials are the composition of sand, gypsum, powder and water, etc. Table 1 includes the thickness and the compressive strength of overlying strata of coal and rock mass. The model size is 3 × 0.2 × 1.2 m. The additional dead weight is applied on the top of the model to simulate gravitation force from the overburden strata.
