岩层移动内外“类双曲线”整体模型研究

岩层移动主要关注工作面上覆部分岩层移动规律,开采地表沉降则关注地面的沉降问题,这2个研究方向都涉及到开采后上覆岩层到地表土层的整体移动行为,可以建立一种能够描述覆岩移动到地表沉降的岩层整体移动模型。通过理论与试验分析得到了岩梁梯形块体结构的初次破断与周期破断形态,建立了岩层梯形“倒漏斗式”冒落拱与裂隙拱的冒落条件与判定方法。基于岩层破断移动边界“类双曲线”模型,提出了采用内外“类双曲线”模型来描述岩层移动与地表沉降规律。内“类双曲线”模型指的是覆岩冒落拱与地表沉降移动拱“类双曲线”模型,在关键层近似“上下”对称;外“类双曲线”模型指的是岩层破断移动边界“类双曲线”模型,在工作面的中垂线附近近似“左右”对称。内“类双曲线”隐含在覆岩内部,可通过地球物理探测方法近似获得;外“内双曲线”体现在地表沉陷、岩层冒落等外部形态。通过理论分析、实例验证以及UDEC数值计算方法验证了厚松散层水平煤层开采条件下岩层移动与地表沉降内外“类双曲线”模型。此外,还分析了内外“类双曲线”共轭形成条件、影响因素与整体运移规律。结果表明:在厚松散层水平煤层开采条件下,建立岩层移动与地表沉降内外“类双曲线”模型理论预测值与实际值误差较小,表明岩层整体移动存在“类双曲线”特征。

Investigation on the inner and outer analogous hyperbola model(AHM)of strata movement

The traditional strata movement pays attention to the strata movement law of the overlying part of the working face,and the mining surface settlement pays more attention to the surface subsidence.These two different research directions are essentially related to the overall movement behavior of the overlying strata and the surface soil layer after mining.It is necessary to develop an overall movement model of the mining strata which can better describe the laws of the overlying strata movement and surface subsidence.Through theoretical and experimental analysis,the initial and periodic fracture patterns of the rock beam trapezoid block structure are obtained,and the caving conditions and judgment methods of the trapezoid“inverted funnel”caving arch and fissure arch are established.Based on the analogous hyperbola model(AHM)of strata movement boundary proposed by the authors,the AHM inside and outside is further proposed to describe the laws of strata movement and surface subsidence.The internal AHM model refers to the AHM of mining overburden caving fracture arch and surface subsidence moving arch,which is symmetrical about the key layer“up and down”.The external AHM refers to the“quasi hyperbolic”model of rock movement boundary,which is approximately“left and right”symmetrical about the coordinate axis working surface near the vertical line.The inner AHM exists inside the overlying rock,which can be approximately detected by geophysical detection methods.The outer AHM is reflected in the surface subsidence,rock collapse and other external forms.Through theoretical analysis,case study and discrete element UDEC method,the unified analogous hyperbola model of strata movement and surface subsidence is verified,and the formation conditions,influencing factors and overall migration rules of AHM of conjugate internal and external are analyzed.The results show that the error between the theoretical prediction value and the actual value of the analogous hyperbola model is small,which reflects the rationality of the AHM of the overall movement of the strata.