为研究采动地表出现斑裂时工作面开采宽度及斑裂线与工作面的动态关系,以华丰煤矿1409工作面地质条件为背景,建立了厚硬覆岩的力学模型,得出了地表移动斑裂产生的判据。根据判据条件探讨了开采宽度与地表水平方向最大拉应力的关系,随着开采宽度的增大,地表最大拉应力也逐渐增大,当拉应力达到岩石抗拉强度时,岩体沿与拉应力垂直方向产生斑裂,从而得出地表移动产生斑裂时工作面的宽度及斑裂线距工作面的水平距离。经计算,当1409工作面临界开采宽度为127 m时,水平方向最大拉应力即达到了岩石抗拉强度,而工作面实际开采宽度为150 m,实测在距工作面下平巷398 m处产生斑裂,而预测值为410 m,预测值与实测值基本相符。

In order to study the mining width of the coal mining face and the dynamic relationship between the surface crack line and the coal mining face when the ground cracks occurred on the surface above the mining, based on the geological conditions of No. 1409 coal mining face in Huafeng Mine as the background, a mecha nics model of thick and hard overburden strata was established and the criterion of the surface movement cracks occurred was provided.The criterion discussed the rel ationship between the mining width and the max tensile stress of the surface in horizontal direction.With the mining width increased, the max tensile stress of the surfac e would be steadily increased.When the tensile stress reached the tensile strength of the rock, the surfaae cracks of the rock would be occurred along the vertical direct ion of the tensile stress and thus the width of the coal mining face when the cracks occurred with the surface moved and the horizontal distance of the crack line to the coal mining face were obtained .According the calculatio, when the critical width of No. 1409 coal mining face was 127 m, the max tensile stress in a horizontal direction reached the tensile strength of the rock and the actual mining width of the coal mining face would be 150 m.The site measurement showed the cracks occurred at 398 m of the gateway to the coal mining face and the predicted value was at 410 m of the mine roadway.Thus the predicted value and the actual measured value were basic ally the same.

国家重点基础研究发展计划(973计划)资助项目(2011CB411906)；国家自然科学基金资助项目(51034003,51274132)；教育部博士学科点专项科研基金资助项目(20103718110001)；