Mine strata behavior law affected by overburden strata structure above fully-mechanized top coal caving mining face in shallow depth seam

In order to control the stability of the overburden strata and to ensure the safety mining operation of the fully-mechanized top coal caving mining face, a similar simulation experiment and the site observation method combined method was applied to study the overburden strata structure affected to the mine strata behavi or law of the fully-mechanized top coal caving mining face under the condition of the shallow depth. The results showed that when the thickness of the base rock was le ss than 80 m, the overburden strata above the fullymechanized top coal caving mining were existed in a form of " cantilever beam + articulated rock beam + arch" struct ure. But when the thickness of the base rock was higher than 80 m, the overburden strata were existed in a form of the " cantilever beam + articulated rock beam". With the thickness of the base rock increased, the stability of the overburden strata structure would be better. With the thickness of the base rock increased, the average circ ulated terminal resistance of the powered support applied to the fully-mechanized top coal caving mining face would be reduced in logarithm. With the thickness of the base rock increased, the average periodic roof weighting step distance would be in an increased tendency. Under the condition of the same overburden strata structure, the dynamic load coefficient would be increased with the thickness of the base rock increased. But under the condition of the different overburden strata structure, the s tability of the overburden strata would be better and the dynamic load cofficient would be smaller.