【作者】 宋世杰；

【导师】 王双明； 赵晓光；

【作者基本信息】 西安科技大学 ， 地质工程， 2013， 博士

【摘要】 煤炭开采过程会产生一系列的地质环境问题，尤以开采沉陷最为突出。明确影响开采沉陷的关键因子，研究更为准确的开采沉陷预计方法是贯彻“预防为主”理念首要解决的问题。本文以陕北榆神府煤矿区为研究区，通过灰色关联和逐步回归分析法筛选了影响开采沉陷的关键地矿因子；研究了煤系覆岩层状结构及特征影响开采沉陷的基本规律；提出了“分层传递”的预计方法，构建了基于关键地矿因子的开采沉陷分层传递预计模型，并通过实例验证了模型的可靠性和准确性。主要结论如下：（1）筛选出榆神府矿区影响开采沉陷的关键地矿因子，并构建了基于关键地矿因子的下沉系数预计模型。以下沉系数为参照系，运用灰色关联分析和逐步回归分析两种方法分别对影响开采沉陷的关键地矿因子进行筛选，最终确定扰动系数（n）、覆岩综合硬度（Q）、深厚比（R0）、宽深比（1）4个影响因子为关键地矿因子。运用多元统计回归方法，构建了基于关键地矿因子的下沉系数预计模型，模型检验结果表明：平均误差为10%，精度满足应用要求。（2）建立了2-2煤层覆岩层状结构框架模型，构建了18种等深且基岩等厚条件下不同的覆岩层状结构类型。在分析钻孔资料的基础上，建立了研究区2-2煤层覆岩层状结构框架模型和划分了基岩段岩层结构，以砂岩层数、砂岩平均厚度和砂泥比作为变量，构建了等深且基岩等厚条件下18种不同类型的覆岩层状结构模型。（3）运用岩体基本质量指标分级法、结构力学分析和数值模拟实验三种方法研究了等深且基岩等厚条件下砂岩层数对下沉系数影响的基本规律。研究结果表明：第一，在基岩总厚度恒定的条件下，随着岩层数量的增加，岩体质量和整体稳定性变差，抗干扰能力随之变弱；第二，在弹性变形和相同荷载作用下，砂层系数的增加会增大整个岩体内最大拉应力和最大挠度，从而放大荷载对岩体的影响强度和效应；第三，在既定砂泥比条件下，下沉系数表现出随砂层系数增加而增大的变化规律，并存在迅速增大、缓慢增大和趋于稳定三段式变化过程；第四，当砂层系数达到或超过70%时，下沉系数基本趋于稳定，此时可以忽略砂岩层数对下沉系数的影响。并建立了不同砂泥比条件下砂层系数与下沉系数的拟合方程。（4）研究了等深且基岩等厚条件下砂岩平均厚度对下沉系数的影响规律。研究结果表明：第一，在基岩总厚度恒定的条件下，砂岩平均厚度越大，岩体基本质量和整体稳定性就越大，抗干扰能力也越强；第二，在相同荷载作用下，砂岩平均厚度的增加会降低整个岩体内最大拉应力和最大挠度，从而缩小荷载对岩体的影响强度和效应；第三，下沉系数表现出随砂岩平均厚度增大而减小的变化规律，并存在迅速减小和趋于稳定两段式变化过程。建立了砂岩平均厚度与下沉系数的拟合方程。（5）研究了等深且基岩等厚条件下砂泥比对下沉系数的影响规律。第一，在基岩总厚度恒定的条件下，砂泥比的增大可以提高岩体基本质量和岩体稳定性；第二，在相同荷载作用下，砂泥比的增大会降低岩体内最大拉应力和最大挠度，从而缩小荷载对岩体的影响强度和效应；第三，在既定砂层系数条件下，下沉系数表现出随砂泥比的增大而减小的变化规律；第四，当砂层系数达到或超过90%时，不同砂泥比所对应的下沉系数表现出明显的收敛、趋同特征，此时可以忽略砂泥比对下沉系数的影响。（6）针对煤系覆岩层状结构在开采沉陷发生发展的作用，提出了分层传递预计思想和方法。基于煤系覆岩层状结构特点，认为地表的下沉移动实际上是岩层通过传递叠加效应将井下采煤扰动最终反映在地表的结果，并由此提出了开采沉陷分层传递预计方法的客观依据、基本思路和条件假设。（7）构建了基于关键地矿因子的开采沉陷走向主断面下沉分层传递预计模型和全结构模型。在“分层传递”预计思想和方法的指导下，以概率积分法模型和“关键层—砌体梁”理论模型为基础，并依据关键地矿因子、砂层系数、砂岩平均厚度、砂泥比等对下沉系数进行修正，构建了基于关键地矿因子的开采沉陷走向主断面下沉分层传递预计模型。并通过理论分析将该模型扩展至全结构模型。（8）建立了基于关键地矿因子的地表移动与变形分层传递预计模型。在“分层传递”预计思想和方法的指导下，建立了基于关键地矿因子的地表移动与变形分层传递预计模型体系，包括：下沉盆地主断面任意点下沉、倾斜、曲率、水平移动、水平变形、扭曲变形和剪切变形预计模型。（9）通过工程实例验证了基于关键地矿因子的开采沉陷分层传递预计模型的可靠性和准确性。以位于不同地域、不同矿区的3个煤矿为实例，对基于关键地矿因子的开采沉陷走向主断面下沉分层传递预计模型进行了实证研究。结果表明：该模型不仅具有较高的精度（平均误差率一般在15%左右，最小误差率可达1%以下），而且相对于概率积分法模型，在下沉盆地走向主断面边界预计精度可明显提高。更多还原

【Abstract】 A series of geological environment problems occur during coal exploitation and themining subsidence is the most prominent. Confirming the key factors of the mining subsidenceand finding more accurate method are the most important problems to be resolved for carryingout the idea of prevention first. Taking the Yushenfu coal mining area in northern Shaanxiprovince as our study area, this article selected the key geological and mining impact factors ofthe mining subsidence with grey correlation analysis method and stepwise regression analysismethod; it studied the basic law of layered structure and characteristics of overburdenimpacting the mining subsidence; it proposed stratification transfer prediction method,constructed the stratification transfer prediction model of the mining subsidence based on thekey geological and mineral factors, and verified the reliability and accuracy of the modelthrough engineering examples. The main conclusions are as follows:(1) The research confirmed the key geological and mining impact factors of the miningsubsidence in the Yushenfu coal mining area and constructed the prediction model of thesubsidence factor based on the key geological and mining factors. Taking the subsidence factoras reference system, the paper screened the key geological and mining impact factors of themining subsidence with grey correlation analysis method and stepwise regression analysismethod and selected four key geological and mining impact factors which are perturbationcoefficient, syntheical protodyakonov hardness of overburden, the ratio of mining depth andheight, width-depth ratio finally. With the multivariate statistical analysis method, theprediction model of the subsidence factor based on the key geological and mining factors isconstructed in the passage, and the test results show that the average error is10%, so theprecision of the model can meet application requirement. (2) The passage established framework model of layered structure of2-2coal seamoverburden and constructed18different types of layered structure in the condition of samedepth and bedrock thickness. On the basis of analyzing borehole data, the paper establishedframework model of layered structure of2-2coal seam overburden and bedrock. Taking thequantity of sandstone layers, the average thickness of sandstone and sand-shale ratio asvariables, the paper constructed18different types of layered structure under the condition.(3) The article researched the basic law of sandstone layers quantity impacting thesubsidence factor with three different methods which are classification of rock mass basicquality index, structure mechanics analysis and numerical simulation test, under the conditionof same depth and bedrock thickness. The research results show that: firstly, in the condition ofsame bedrock thickness, with the increase of the quantity of sandstone layers, the basic qualityand whole stability of rock mass become worse, so does the anti-interference ability of rockmass; secondly, under the effect of elastic deformation and same loads, the increase ofsandstone layer coefficient may increase the maximum tensile stress and maximum deflectionof the whole rock, which would magnify the intensity caused by the same loads; thirdly, in thecondition of fixed sand-shale ratio, the law that subsidence factor increases with the increaseof sandstone layer coefficient is discovered, and its change process includes three stages whichare rapid increase, slow increase and tendency of stability; fourthly, when the sandstone layercoefficient is more than70%, the subsidence factor tended to be stable, the effect of thequantity of sandstone layers can be neglected. Then the fitted equations of sandstone layercoefficient and subsidence factor under different sand-shale ratio are established.(4) The paper studied the basic law of the average thickness of sandstone impacting thesubsidence factor under the condition of same depth and bedrock thickness. The researchresults show that: firstly, in the condition of same bedrock thickness, with the increase of theaverage thickness of sandstone, the basic quality and whole stability of rock mass increase,and the anti-interference ability of rock mass is stronger; secondly, under the same loads, withthe increase of the average thickness of sandstone, the maximum tensile stress and maximumdeflection are decreased so that the affecting intensity caused by the same loads is reduced;thirdly, the law that subsidence factor decreases while the average thickness of sandstoneincreases is discovered, and its change process includes two stages which are rapid decreasedand tendency of stability. The fitted equation of the average thickness of sandstone andsubsidence factor is established.(5) The paper studied the basic law of the sand-shale ratio impacting the subsidencefactor in the condition of same depth and bedrock thickness. The research results show that: firstly, in the condition of same bedrock thickness, with the increase of the sand-shale ratio, thebasic quality and whole stability of rock mass increase; secondly, under the same loads, withthe increase of the sand-shale ratio, the maximum tensile stress and maximum deflection aredecreased so that the affecting intensity caused by the same loads is reduced; thirdly, in thecondition of fixed sand-shale ratio, the law that subsidence factor decreases while thesand-shale ratio increases is discovered; fourthly, when the sandstone layer coefficient is morethan90%, the subsidence factors corresponding to the different sand-shale ratios areconvergence, in this case the effect of the sand-shale ratio can be neglected.(6) According to the function of layered structure of overburden in the occurrence anddevelopment of mining subsidence, the research proposed the idea and method of thestratification transfer prediction. Considering the characteristics of layered structure ofoverburden, the paper holds that surface subsidence is the final result of mining disturbancethrough the effect of transfer and superposition by stratum, therefore, it proposed the objectivebasis, basic thinking and conditions of the stratification transfer prediction method.(7) The research constructed the stratification transfer prediction model and the wholestructure model of the mining subsidence based on the key geological and mining factors inthe trend main section of subsidence basin. Under guidance of the idea and method of thestratification transfer prediction, taking the models of probability integral method and “keystratum-voussoir beam” theory as the foundation, the paper constructed the stratificationtransfer prediction model of the mining subsidence based on the key geological and miningfactors in the trend main section of subsidence basin, and meanwhile corrected the subsidencefactor in the new model according to the key geological and mining factors, the quantity ofsandstone layers, the average thickness of sandstone and sand-shale ratio. Through theoreticalanalysis, the model was extended to the whole structure model.(8) The stratification transfer prediction model of the surface movement and deformationbased on the key geological and mining factors was established. Under guidance of the ideaand method of the stratification transfer prediction, the stratification transfer prediction modelof the surface movement and deformation based on the key geological and mining factors wasestablished, including subsidence, incline, curvature, horizontal movement, horizontaldeformation, distortion deformation and Shear deformation of any point in the main section ofsubsidence basin.(9) Through engineering examples, the research verified the reliability and accuracy ofthe stratification transfer prediction model of the mining subsidence based on the keygeological and mining factors. Taking three coal mines located in different regions and mining areas as examples, an empirical study on the stratification transfer prediction model of themining subsidence based on the key geological and mining factors in the trend main section ofsubsidence basin was done. The results show that: not only does the model have high precision(the average error rate is about15%normally, the minimum error rate is less than1%), butalso the prediction precision of the model can be improved on the boundary of the trend mainsection of the subsidence basin relative to the model of probability integral method.更多还原