神东矿区超大工作面开采沉陷参数取值研究

神东矿区超大工作面开采对环境影响剧烈。针对超大工作面开采地表沉陷参数精确取值的问题,根据研究区地质采矿条件设计了4个因素、5个水平正交数值模拟试验方法,研究工作面参数对沉陷参数的影响规律,并给出适合现场条件的概率积分法预测参数。采用有限差分数值模型并结合由正交设计得到的25个模拟试验方案,计算模型地表的移动变形数据和沉陷参数,包括下沉系数、水平移动系数和走向边界角。用方差分析法提取对沉陷参数影响显著的工作面参数,发现下沉系数受工作面倾向长度影响显著,水平移动系数受采厚和工作面推进距离影响显著,边界角受采厚影响显著。对正交试验结果进行最小二乘拟合,得到了由工作面参数计算下沉系数、水平移动系数的公式。在研究区地质采矿条件下,这两个系数应分别取0.532、0.266,输入沉陷预测软件计算的结果与实测数据吻合良好。研究可为类似条件下矿区超大工作面地表沉陷预计参数精确取值提供参考。

Determiantion Study on the Mining Subsidence Parameters of Super-large Working Face in Shendong Coalfield

Exploitation of super-large working faces strongly influences the ground environment in Shendong Coalfield. In order to obtain the accurate subsidence parameters induced by the excavation of super-large working face,according to the geological and mining conditions of the study area,the orthogonal numerical simulation tests based on four factors and five lev-els are designed,so as to study the influence regularity of working face parameters on the subsidence parameters,and provide the prediction parameters of probability integral method that is suitable for the field conditions.Based on finite difference nu-merical model and the 25 simulation test schemes obtained by orthogonal design,the surface deformation data and subsidence parameters (including vertical subsidence coefficient,horizontal displacement coefficient and border angle in strike direction) of the model are calculated.The working face parameters which have significance influence on subsidence parameters are ex-tracted by using variance analysis method.It is indicated that the vertical subsidence coefficient is significantly affected by working face dip length,horizontal displacement coefficient is significantly affected by mining thickness and working face ad-vance distance and the border angle in strike direction is influence significantly by mining thickness.The least square method is used to fit the orthogonal test results,the computational formulas of subsidence coefficient and horizontal displacement coef-ficient based on working parameters are obtained.Under the geological and mining conditions of the study area,the optimal val-ues of vertical and horizontal subsidence coefficients are 0.532 and 0.266.The mining subsidence computation results of the mining prediction software based on the above coefficients is basically consistent to the actual measured data.The above study ideas can provide some reliable reference for determining the optimal mining subsidence parameters of the super-large work-ing face in Shendong Coalfield.