厚冲积层矿区地表移动持续时间预测方法研究

Study on prediction method of surface movement duration in thick alluvial mining area

地表移动持续时间是地表沉陷稳定的关键指标,精确预计该时间对于地表及地面设施的稳定性评估至关重要。由于厚冲积层的特殊性及现有方法考虑影响因素有限,导致现有方法在厚冲积层矿区预测误差偏大。针对这一问题,综合考虑了采深、采厚、冲积层厚度和推进速度等地表移动时间影响因素,基于淮南潘谢新区15个工作面的实测数据,分析了各影响因素与地表移动持续时间的关系,建立了厚冲积层矿区地表移动持续时间新计算模型,分析了计算模型精度,并利用SBAS-InSAR技术进行了实测验证。研究结果表明:地表移动持续时间与采厚、采深呈正相关,与推进速度、冲积层厚度呈负相关;分别利用参与和未参与建模的数据进行计算,得到新模型的精度提高了86%和44%;新建模型计算结果与Sentinel-1数据解算结果的相对误差最低为7.2%,再次证实了该计算方法的正确性。对比传统经验公式,新建公式适用性更强,精度更高,可为厚冲积层矿区地基稳定性评价等相关工作提供技术支撑。

The surface movement duration is a key index of surface subsidence stability, it is very important to accurately predict the time for the stability evaluation of surface and ground facilities. Due to the particularity of thick alluvium and the limited consideration of influencing factors by existing methods, the prediction error of existing methods in thick alluvial mining areas is too large. In order to solve this problem, the influencing factors of surface movement time, such as mining depth, mining thickness, alluvium thickness and advancing speed are comprehensively considered. Based on the measured data of 15 working faces in Panxie New Area of Huainan, the relationship between the influencing factors and the duration of surface movement was analyzed, and a new calculation model of surface movement duration in thick alluvium mining area was established, and then the accuracy of the calculation model was analyzed, and the SBAS-InSAR technology was used to verify the actual measurement. The results show that: the duration of surface movement is positively correlated with mining thickness and mining depth, and negatively correlated with advancing speed and alluvium thickness;the accuracy of the new model is improved by 86% and 44% by using the data that involved in and did not involve in the modeling respectively. The relative error between the calculation results of the new model and the Sentinel-1 data calculation results is at least 7.2%,which confirms the correctness of the calculation method again. Compared with the traditional empirical formula, the new formula in this paper has stronger applicability and higher accuracy, which can provide technical support for related work such as foundation stability evaluation in thick alluvium mining area.