RESEARCH ON COMBINED MOTION CHARACTERISTICS OF OVERLYING ROCK STRATUM AND POSITION OF KEY STRATUM
覆岩组合运动特征及关键层位置研究

The combined motion of the overlying rock stratum of coal mine is regarded as a motion of the compound key stratum sustained by stiff rock stratum. The stress of the compound key stratum is discussed by using the elastic thin plate theory and the laminated plate theory of the compound material mechanics. The collapsing load of the key stratum is obtained by adopting the plastical limit analysis method structure. Based on the collapsing load,the posotion of key stratum can be estimated approximatively.