The 20~40m thick Quaternary overburden is overlaid on coal seam II1 in the Liuhe coalmine, Henan, in which, average thick-ness of clay beds is 6.6m. Since the 4 water-bearing sectors in Quaternary pore water aquifer group are all aquifers with medium water yield property and even higher. Thus, if the clayey soil can withstand roof water inrush under impact from overhead high pressure is cru-cial, that is key problem to solve safe mining under Cenozoic aquifers. Through laboratory physical parameter and soil grain size tests of 4 soil core samples from depth about 150m, based on tested results simulated deep clayey soil, considering three main factors impact-ing clayey soil destruction including stressed area, specific moisture content and thickness, using orthogonal experiment principle to ar-range tests. The result has shown that the higher the stressed area and specific moisture content, the larger clayey soil destruction ex-tent; the larger the clayey soil thickness, the smaller the corresponding destruction extent. Among the three factors, impact from stressed area is the largest;when clayey soil specific moisture content is 10%~25%with smaller stressed area and larger thickness, de-struction of clayey soil is not easy to occur. The study has major significance in prevention of water disaster and to ensure safe mining.%河南刘河煤矿矿二1煤层上为厚度20～40m的第四系覆盖层，其中黏土层平均厚度为6.6m。由于第四系孔隙水含水组的四个含水段均为富水性中等及以上含水层，所以该层黏性土在受到上覆高压影响后能否控制顶板突水显得尤为关键，是解决新生界含水层下的安全开采的关键问题。通过室内实验测得该矿深度约在150m的4个钻孔土样的物理参数和土颗粒级配分析，按实验结果模拟深层黏性土，考虑受力面积、含水率和厚度3个影响黏性土破坏的主要因素，利用正交实验原理安排实验。结果表明，受力面积和含水率越大，黏性土的破坏程度增大；黏性土的厚度越大，破坏程度相应减小；3个因素中，受力面积的影响最大；当黏性土含水率在10%～25%，受力面积越小，厚度越大，黏性土不易发生破坏。该研究对预防和保证矿山安全生产具有重要意义。
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