走向充分采动地表下沉速度计算模型

    Calculation model for surface subsidence velocity in full strike mining

    • 摘要: 针对目前走向充分采动引起的地表下沉速度预测模型相对较少的研究现状,在改进Knothe时间模型基础上,根据极值原理提出了走向充分采动地表最大下沉速度计算方法,并与现有理论类和经验类计算方法进行了对比分析。其后,结合地表下沉速度曲线近似呈正态分布特征,建立了走向充分采动地表下沉速度预测模型,并给出了模型参数确定方法。最后,采用淮南某矿和补连塔矿工作面走向充分开采地表沉陷速度监测数据验证预测模型的精确性和合理性。结果表明:2个矿区工作面走向充分采动地表最大下沉速度理论计算值与实测值误差平均值分别仅为1.01 mm/d和3.52 mm/d,验证了地表最大下沉速度计算方法的精确性;走向充分采动地表下沉速度模型预测2个矿区的地表下沉速度曲线基本与实测曲线基本重合,两者标准差平均值分别仅为1.7 mm/d和2.2 mm/d,验证了理论模型的精确性和合理性。实测曲线和理论曲线在开切眼一侧基本吻合,在工作面终采线一侧预测值大于现场监测值,一方面是由于工作面终采线一侧的采动影响存在滞后现象,致使回采至工作面位置时,采动影响未全部传递至地表,引起的地表下沉剧烈程度没有充分显现;另一方面是由于地表下沉速度曲线并非严格满足正态分布。

       

      Abstract: In view of the current research status that relatively few prediction models exist for surface subsidence velocity induced by full strike mining, a calculation method for the maximum surface subsidence velocity in full strike mining was proposed based on the extreme value principle with the improvement of the Knothe time function model, and a comparative analysis was conducted on its advantages over the existing theoretical and empirical calculation methods. Subsequently, combined with the characteristic that the surface subsidence velocity curve approximately follows a normal distribution, a prediction model for surface subsidence velocity in full strike mining was established, and the determination method for model parameters was given. Finally, the accuracy and rationality of the prediction model were verified using the field monitoring data of surface subsidence velocity from full strike mining working faces in a coal mine in Huainan and Bulianta Coal Mine. The results show that the average errors between the theoretical calculated values and the measured values of the maximum surface subsidence velocity in full strike mining of the two mining areas are only 1.01 mm/d and 3.52 mm/d, respectively, which verifies the accuracy of the proposed calculation method for the maximum surface subsidence velocity. The surface subsidence velocity curves predicted by the model for the two mining areas are basically consistent with the measured curves, with the average standard deviations of only 1.7 mm/d and 2.2 mm/d, respectively, which further verifies the accuracy and rationality of the theoretical model. The measured curves are basically consistent with the theoretical curves on the side of the open-off cut, while the predicted values are higher than the field monitoring values on the side of the final mining line of the working face. This phenomenon is attributed to two aspects: on the one hand, the mining influence on the side of the final mining line has a lag effect, so that when mining reaches the working face position, the mining influence is not fully transmitted to the surface, and the intensity of surface subsidence is not fully manifested; on the other hand, the surface subsidence velocity curve does not strictly conform to a normal distribution.

       

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