Relevant Data.

A mechanical analysis model was constructed for the clay layer. Using a combined approach of theoretical analysis and numerical simulation, the failure state of this layer during coal seam extraction under thin bedrock conditions was investigated. The findings offer insights for evaluating the water-blocking performance of the Cenozoic clay layer and for preventing water inrush disasters in similar geological settings. The key findings are as follows: (1) The most critical factor governing clay layer failure is the amount of bedrock subsidence following collapse. As the subsidence of the fractured bedrock increases, the suspended section of the overlying clay layer extends, elevating its possibility to shear or tensile failure. (2) Variations in bedrock thickness markedly influence the subsidence of both the bedrock and the clay layer. Consequently, bedrock thickness is a primary determinant of the degree of damage sustained by the clay layer. (3) The minimum bedrock thickness required to prevent failure of the basal clay layer within the Cenozoic overburden ranges from 33 m to 38 m. If the bedrock thickness falls below 33 m, the clay layers will be damaged after coal seam mining, leading to a loss of their water-blocking capacity.

针对黏土层构建了力学分析模型。采用理论分析与数值模拟相结合的方法，对薄基岩条件下煤层开采过程中该黏土层的破坏状态进行了研究。研究结果可为新生代（Cenozoic）黏土层的隔水性能评价以及类似地质条件下的突水灾害防治提供参考。主要研究结论如下：
(1) 影响黏土层破坏的最关键因素为基岩垮落后的沉降量。随着破碎基岩的沉降量增大，上覆黏土层的悬露区段随之延伸，提升了其发生剪切或拉伸破坏的可能性。
(2) 基岩厚度的变化会显著影响基岩与黏土层的沉降量，因此基岩厚度是决定黏土层破坏程度的核心因素。
(3) 新生代覆盖层内底部黏土层免于破坏所需的最小基岩厚度介于33 m至38 m之间。若基岩厚度低于33 m，煤层开采后黏土层将发生破坏，进而丧失其隔水性能。