中文摘要：

为了确定老虎台矿特厚煤层不同开采阶段＂弱-弱＂结构覆岩破坏高度,以63005工作面所在区域为研究对象,构建FLAC（3D）数值计算模型,对研究区域水砂充填开采阶段和综采放顶煤开采阶段覆岩破坏高度进行分析,确定了覆岩破坏高度与采出厚度的关系。分别采用微震监测、EH-4探测法对研究结果进行了验证。结果表明：无论水砂充填开采阶段还是综采放顶煤开采阶段,老虎台矿＂弱-弱＂结构覆岩最大破坏高度均约为等效采高的8.5倍;63005工作面开采前后,覆岩破裂最大高度与油母页岩和绿色页岩的分界面密切相关,均被控制在分界面之下;覆岩破坏高度受到F（18）断层的影响,被约束在断层破碎带沿走向范围内;63005工作面开采后,绿色页岩层中F（18）断层的下盘出现离层破坏,且破坏范围呈逐步扩大的趋势。

英文摘要：

This paper is inclined to report the results of our research on the changes of the overburden failure heights in the sand backfilling phase and/or fully mechanized top coal caving phase respectively in the case of the ultra-thick coal seams with ＂weak-weak＂ overburden structure.The problem has to be regarded as a reference for predicting and preventing water inrush accidents for Laohutai coal mine,Liaoning.For the above-mentioned purpose,we have done necessary tests with the following three methods.First of all,we have built up a FLAC~（3D） numerical calculation model based on the original geological conditions of the region of No.63005 working face,in which we have done tests over the physical and mechanical parameters of the coal,oil shale,green shale and tuff in the above-mentioned model three times in the different excavation phases.Based on the parameter testing and calculations,we have analyzed the relationship between the failure height and the equivalent mining heights.As the result of analysis,we have detected that the maximum overburden failure height tends to come about on the average 8.5 times the equivalent mining height in the above said mine,no matter whether the work has been done in the sand backfilling phase or in the fully mechanized top coal caving phase.And,then,we have taken the microseismic monitoring and EH- 4 detection method to verify the calculation results,respectively,finding that we can make the same conclusion with the former method the paper has mentioned above.At the same time,it can be found that through the microseismic monitoring and EH-4 detection method,we can also find that the failure height should be closely related to the interface between the oil shale and the green shale.Such failure heights can also be affected by the F_（18） Fault no matter whether it would take place before or after the said working face No.63005 of the mine is put into operation,though it is controlled both by the interface and the fault fracture zone in performance.And,since the said work