平煤矿区首次开采近全岩下保护层工作面用于解放其上部受瓦斯突出威胁的己组煤炭资源，近千米埋深开采近全岩层势必加大底板破坏深度，一旦扰动隔水层内L5弱富水性含水层形成寒灰水间接补给通道，影响工作面底板安全稳定。为此首先建立双层结构底板塑性滑移线场理论模型，推导出三种工况下双层底板最大破坏深度解析解；然后通过自主设计的孔隙水压力（弹簧）和地层有效应力（千斤顶）协同工作的相似模拟试验平台，基于数字图像相关技术模拟分析了采场顶底板变形形态和破坏特征；最后使用钻孔应变测量方法在平煤十二矿己15-31040近全岩工作面开展底板破裂发育形态现场监测。结果表明：采用双层结构底板塑性滑移线场理论计算出己15-31040近全岩工作面底板最大破坏深度为16.59 m；相似模拟试验揭示了底板破坏集中于开切眼及工作面两端，具有明显滞后破坏特征，最大破坏深度为17.8 m，工作面推进159.9 m进入充分开采后，底板应力逐渐恢复；现场实测结果显示底板岩体在工作面前方7.9 m出现压剪滑移破坏，工作面推过钻孔前后底板分别表现出压剪和拉剪破坏，底板最大破坏深度介于16.5～18 m。现场实测与理论计算和相似模拟试验结果较为吻合，研究成果有利于推动大埋深、高承压煤岩层开采底板水害防治技术的进步。

The first mining of nearly whole rock lower protective layer working face in Pingdingshan coal mining area is used to liberate the Ji group coal resources of its upper threatened by the gas outburst. The mining of the rock layer at a depth of nearly 1000 meters is bound to increase the depth of the floor damage. Once the L5 weak water-rich aquifer in the aquifuge is disturbed, the indirect recharge channel of the cold ash water is formed, which affects the safety and stability of the rock floor. Firstly, the theoretical model of plastic slip line of double-layer structure floor is established, and the analytical solution of maximum failure depth of double-layer floor under three working conditions is derived. Then through the self-designed similar simulation experimental platform of pore water pressure (spring) and stratum effective stress (jack), the deformation form and failure characteristics of stope roof and floor are simulated and analyzed based on digital image correlation technology. Finally, the borehole strain measurement method was used to carry out on-site monitoring of floor fracture development morphology in Ji15-31040 nearly whole rock working face of Pingdingshan No.12 Coal Mine. The results show that the maximum failure depth of Ji15-31040 nearly whole rock working face floor is 16.59 m by using the plastic slip line theory of double-layer structure floor. The similar simulation experiment reveals that the floor failure is concentrated at both ends of the open-off cut and the working face, with obvious lagging failure characteristics. The maximum failure depth is 17.8 m. After the working face advances 159.9 m into full mining, the floor stress gradually recovers. The field measurement results show that the floor rock mass has a compression-shear slip failure at 7.9 m in front of the working face. The floor before and after the working face is pushed through the borehole shows compression-shear and tension-shear failure, respectively. The maximum failure depth of the floor is between 16.5 m and 18 m. The results of field measurement are in good agreement with theoretical calculation and similar simulation test.