对薄基岩浅埋煤层覆岩的隔水性进行了分析,采用相似材料模拟的方法,研究了薄基岩浅埋煤层覆岩的物理力学特征和上覆岩层移动破坏规律。研究表明,覆岩的矿物成分以石英、钾长石等为主,其含量高达75．4%~92．0%；岩石的单向抗压强度远大于抗拉强度,属于典型的脆性岩石。风化岩石的膨胀性增强,塑性增加,强风化带内,结构致密的粉砂岩、细粒砂岩的物理力学性质无明显变化。相似模拟实验表明：在煤柱附近和采空区中央,沿顶板方向覆岩移动表现出明显的分区性,在同一层位水平变形引起的压缩区和拉伸区交错出现；导水断裂带最大高度约为94 m,是采高的27倍。在此基础上,对薄基岩浅埋煤层保水开采的条件进行了评价,提出了保水开采的关键技术措施。%In this paper, analysis was made on the water-resisting propery of the overlaying strata of the shallow coal seam with thin bedrock, and research was carried out on its physical and mechanical characteristics as well as its movement and failure laws with the similar material simulation method. The research showed that the main mineral compositions of the overlying strata were quartz, potash feldspar and so on, their content was as high as 75. 4% ~92. 0%, the uniaxial compressive strength of the rock was far greater than its uniaxial tensile strength, it belonged to a typical brittle rock. The expansibility of the weathered rock reinforced and its plasticity increased, and in the strongly weathered zone, the physical and mechanical properties of the compact siltstone and fine sandstone had no obvious changes. The Similar simulation experiments indicated that near the coal pillar and at the certer of the gob, the movement of the overlying strata along the roof direction had obvious zoning characteristics, the compression zone and tensile zone caused by the horizontal deformation appeared alternately in the same horizon; the maximum height of water flowing fractured zone was about 94 m, 27 times of mining height. On this basis, water-preserved mining conditions of the shallow seam with thin bedrock were evaluated, and the key technical measures for water-preserved mining were proposed.
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