摘要
煤层开采所引起的地表沉陷是一种严重的矿区地质灾害。煤层的倾角、厚度等物理条件是地表沉陷的主要影响因素。在水平煤层或缓倾斜煤的开采过程中,由于地层倾角小,地表沉陷具有较完整的规律性,其预测效果也比较理想。但是,在急倾斜煤层的开采中,由于地层倾角较大,赋存条件和地质体物理力学性质的差异,增强了地表下沉的非线性特征,使地表沉陷具有不确定的表现规律。文章对重庆市南桐矿区东林矿的地表沉陷非线性特征进行了探讨,得到了东林煤矿地表下沉曲线的分形维数是1 07。在岩层移动这个系统当中,既含有已知的又含有未知的或非确定的信息,可以作为一个灰色系统来研究。岩层控制系统的状态、结构和边界条件难以精确描述,属本征性灰色系统。文章针对东林煤矿地表下沉曲线非线性较弱的性质,提出用一种基于GM(1,1)的渐近预测模型对东林煤矿42个月的地表下沉量时间序列进行探讨。结果表明,这种模型对急倾斜层开采地表沉陷的预测是一种行之有效的方法。通过对其他工程实例的应用分析,进一步证明这种渐近的灰色预测方法具有相对较高的精度,是一种比较实用的地表沉陷预测方法,具有广泛的工程实用空间。
The ground subsidence caused by steep coal seam mining is a severe geological hazard in mining area.The inclination and thickness of coal strata are main influencing factors of ground subsidence.During the excavation of horizontal and gently inclined coal seam,ground movement shows preferable regularity due to small inclination angle.The forecasting result of ground movement is ideal.But during the excavation of steep coal strata,ground movement shows uncertain regularity.It is due to the large inclination angle,position and mechanical charactreistics.These conditions enhance the nonlinear characteristics of ground movement and make it unstable.The nonlinear characteristics of ground subsidence in Nantong coal area are discussed,and it show that the subsidence fractal dimension of Donglin coal mine is 1.07.In the system of strata movement,there are definite and indefinite conditions,so it could be researched as a grey system.Strata control system belongs to grey system because its position,structure and boundary condition are difficult to describe precisely.The nonlinear characteristics of ground subsidence are researched in this paper.An asymptotic grey forecasting method is presented based on GM(1,1)model and the subsidence values of Donglin coal mine during 42 months are calculated.The result shows that the asymptotic grey forecasting method is useful to forecast the ground subsidence in steep coal strata excavation.The case study shows that this asymptotic method could raise forecasting accuracy.It is a practical method to forecast ground subsidence.
出处
《中国地质灾害与防治学报》
CSCD
2004年第1期82-85,共4页
The Chinese Journal of Geological Hazard and Control
基金
高等学校博士点基金资助项目(2000061115)
教育部高等学校优秀青年教师教学科研奖励计划资助项目.
