薄基岩综放采场直接顶结构力学模型分析

为深入研究薄基岩综放采场矿压显现规律，以山西潞安矿业集团司马煤矿薄基岩区厚煤层开采为研究背景，采用数值模拟、理论分析、现场实测等方法对薄基岩综放采场直接顶结构特征进行了研究，建立了薄基岩综放采场直接顶结构力学模型，分析了直接顶“半拱”式平衡结构的形成机理和破断规律。结果表明：根据司马矿薄基岩区直接顶厚度和岩层性质不同，将直接顶划分为Ⅰ型和Ⅱ型两种类型；采高6.5 m，直接顶厚度大于15 m时，容易形成“半拱”式平衡结构，采场矿压呈现出来压步距短、静压大、动压小、动载系数小等特征，“半拱”结构有规律的破断失稳是薄基岩综放工作面矿压显现的根源，该结论解释了司马煤矿薄基岩综放采场的矿压显现规律。

Mechanical analysis of immediate roof in fully mechanized top coal caving mining with thin bedrock

In order to further investigate the mine pressure behavior of thin bedrock in fully mechanized sublevel caving face，this paper took the thick coal seam mining under thin bedrock roof in Sima Coal Mine of Lu’an Group as a case in point.The structural characteristics of immediate roof in longwall top coal caving face with thin bedrock roof were studied by using of numerical simulation，theoretical analysis，in site measurement，etc.Mechanical model of immediate roof in longwall top coal caving face with thin bedrock roof was established，and the formation mechanism and breakage law of semi arch structural model of immediate roof were also analyzed.The results indicate that the immediate roof is divided into two types as type Ⅰ and type Ⅱ based on the thickness and rock properties of immediate roof in Sima Mine thin bedrock area ；semi arch structural model of immediate roof is easily formed，when mining height is 6.5 m and the thickness of immediate roof is more than 15 m ；the phenomenon of short weighting interval，big static pressure，little dynamical pressure，little coefficient of live load is presented in mining pressure behavior ；the regular breaking of semi arch structure is the root of mining properly explains the law of mining pressure behavior of thin bedrock roof pressure behaviors of thin bedrock roof in longwall top coal caving face.The results explains the mine pressure behavior of Sima Coal Mine thin bedrock in fully mechanized sublevel caving face.