基于覆岩层状结构特征的开采沉陷分层传递预计方法

Stratification transfer method of the mining subsidence based on the characteristics of layered structure in coal overburden

  • 摘要: 煤系覆岩层状结构作为煤炭赋存的显著而重要的地质特点,不仅影响着开采沉陷的发展过程,也决定着沉陷后地表最终形态。以陕北榆神矿区2-2主采煤层区域地质赋存条件和小保当井田典型钻孔资料为主要依据,以砂岩层数、砂岩平均厚度、砂泥比等3个覆岩层状结构关键特征为变量,构建了18组覆岩层状结构数值模型。通过数值模拟实验,揭示了它们对下沉系数的影响规律,建立了相应的量化关系。从变形传递叠加的角度,提出了基于覆岩层状结构特征的开采沉陷分层传递预计方法的原理和前提条件,构建了开采沉陷分层传递走向主断面下沉、水平移动与变形预计模型。工程实例验证了该方法较概率积分法具有更高的整体预计精度,可为中国西部煤矿区开采沉陷的防治提供更好的技术支持。

     

    Abstract: Layered structure of overburden is a remarkable and important geological characteristic of coal occurrence.It not only affects the development of mining subsidence, and also determines the final shape of surface subsidence.Based on the geological characteristic of 2-2 coal seam and the representative drilling in the Yushen Coal Mining Area and under the conditions of the same depth and bedrock thickness, 18 simplified models with different types of layered structure of overburden strata were constructed by taking the number of sandstone layers, their average thickness and the sand-shale ratio as variables.Study was made on the influence rule of three characteristics upon the subsidence coefficient through the numerical simulation test, and the corresponding quantitative relationships were constituted.The basic principle and assumed conditions of the stratification transfer method of the mining subsidence based on the characteristics of coal overburden were proposed from the view of transfer and superposition of deformation. The stratification transfer prediction models, including subsidence, horizontal movement and horizontal deformation in the trend main section of subsidence basin were constructed.Engineering example verified that this new method has a higher predic-tion accuracy than the probability integral method, so that it could provide a better technological support for the prevention of mining subsidence in Chinese western coal mining area.

     

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