浅埋采空区顶板应力变形与地表沉降的动态关系分析

地下采空区引起的地表沉降逐渐成为了一种常见的地质灾害,为避免该类灾害发生,越来越多的监测技术与监测设备应运而生,但是目前对于监测数据的分析利用却并不充分。利用弓长岭露天铁矿浅埋空区顶板的锚杆应力计、多点位移计、液压水准仪的多传感器联合监测结果,运用自回归分布滞后模型(Autoregressive Distributed Lag,ARDL)对地表沉降与采空区顶板岩体内的应力、位移之间的动态关系进行了研究。自回归分布滞后模型(ARDL)估计结果表明,浅埋采空区的顶板岩体内产生的应力、位移与地表沉降之间存在长期和短期的影响,且滞后1期的应力、位移对地表沉降的影响最为显著。在上述分析的基础上,提出了相应的多传感器监测信息融合与预测模型构建的对策建议,即可以由采空区顶板岩体内滞后的应力、位移时间序列数据预测地表沉降,由机器学习等算法建立3个变量之间的非线性函数关系,进而构建预测模型,可以有效体现出地表沉降过程中浅埋采空区顶板岩体的响应机理。

Analysis of the Dynamic Relationship between Stress and Deformation in Roof and Ground Subsidence of Shallow Goaf

The ground subsidence caused by underground goaf has gradually become a common geological disaster.In order to avoid this kind of disaster,more and more monitoring technology and equipment came into being,but at present,the analysis and utilization of monitoring data is not sufficient.Therefore,based on the monitoring results of bolt stress meter,multipoint displacement meter and hydraulic level in roof of shallow goaf in Gongchangling Open-pit Iron Mine,the dynamic relationship between ground subsidence and stress and displacement in overburden rock mass of goaf was studied by the autoregressive distributed lag(ARDL)model. The estimation results of the autoregressive distributed lag(ARDL)model show that there are long-term and short-term effects between stress and displacement in overlying rock mass caused by underground goaf and ground subsidence,and the lagging stress and displacement have the most significant impact on ground subsidence.On the basis of the estimated results,the corresponding countermeasures and suggestions for the establishment of multi-sensor monitoring information fusion and prediction model are put forward.The time series data of the lagging stress and displacement in the roof rock mass of the goaf can be used to predict ground subsidence,and the nonlinear function relationship among the three variables can be established by machine learning algorithm to build the prediction model,which can reflect the response mechanism of the roof rock mass of the shallow goaf in the process of ground subsidence.