Abstract: In line with the geological situation,methods of analog simulation,numerical simulation,empirical formula and field measurement are adopted to do some research on the failure characteristics of overlying strata during the full-mechanized caving mining of thick coal seam under thick unconsolidated aquifer so as to obtain the height of the caving zone and fissure zone of the overlying strata.According to the contrast results,the results of the analog simulation and numerical simulation are close to the actual measurement data.However,the height value of fissure zone that is calculated by the empirical formula is lower than the actual value.So,13.5 meters and 68 meters are the hight value of the caving zone and fissure zone respectively.The above research results can provide some basises for designing and retaining of collapse prevention coal and rock pillars in mining area.

Key words: Destruction of overlying strata, Numerical simulation, Analog simulation, Empirical formula