分段Weibull时间函数开采沉陷动态预计研究

Study on Dynamic Prediction of Mining Subsidence with Segmented Weibull Time Function

以地表点最大下沉速度时刻τ为分界点,将动态下沉过程分为前后近似对称的两个阶段,结合偏差改正、生长函数模型等手段消除理论误差,提出一种分段Weibull时间函数,建立了τ与地表点距开切眼距离x的回归方程,并对岩性参数c和k的确定方法进行了探讨,有效改进了Weibull时间函数在动态预计中存在的不足。以山西某矿3214工作面实测数据为依据,对单点及主断面的下沉值进行预测验证,并与Weibull、Knothe以及优化后的分段Knothe函数对比。分析发现,就单个点而言,分段Weibull时间函数的预测精度比上述函数分别提高了41.09%,51.03%,3.47%;对主断面而言,第一期相对误差最大,仅为5.25%.研究表明,分段Weibull时间函数具有一定的可靠性,能够用于沉陷区更高精度的动态预测。

The maximum subsidence speed momentτof the surface point was set as cut-off point to divide the dynamic subsidence process into two phases of approximate symmetry.By combining it with deviation correction and growth function model to eliminate the oretical error,a segmented Weibull function was proposed,the regression equation ofτand the distance x between the surface point and the open hole was established,and the determination method of lithologic parameters c and k was discussed,which effectively improved the deficiency of Weibull time function in dynamic prediction.On the basis of the measured data of 3214 working face in a mine in Shanxi Province,the subsidence values of single point and main section were predicted and verified,and compared with those obtained by Weibull,Knothe and optimized segmented Knothe functions.From the analysis it was found that the prediction accuracy of piecewise Weibull time function is 41.09%,51.03%,and 3.47%higher than above functions,respactively,at a single point.For the main section,the relative error in the first peried is the largest,only 5.25%.The segmented Weibull time function has certain reliability and can be used for dynamic prediction with higher accuracy in subsidence areas.