软岩地层深部开采地表下沉分析

Analysis of Ground Subsidence due to Deep Mining in Soft Rock Strata

针对软岩地层深部地下大面积开采岩体移动变形预测问题,利用弹塑性力学理论建立了相应的预测分析理论模型。用所建立的弹性理论模型对某铁矿地表移动变形进行了计算分析,并将理论预测结果和实测资料进行了对比。文中用弹塑性有限元法分析了不同弹性模量、泊松比、内聚力、内摩擦角等物理力学参数对地表下沉的影响;对软岩地层深部开采地表移动进行了计算分析。结果表明,弹性模量对地表下沉影响较大,而其他参数影响较小。结果表明,弹塑性力学方法适用于分析软岩地层大面积开挖岩体移动预测问题。

The elastic- plastic theoretical model was established for estimating rockmass displacement and deformation due to large scale deep underground mining in soft rock strata. The model was used to predict ground movement and deformation of the iron mine, and the theoretical values were compared with the probability integral results and measured data. The paper utilized the elastic - plastic finite element method to verify that the mechanics parameters had influence on ground subsidence caused by underground mining in soft rock strata. The ground subsidence for different elastic modulus, Poisson＇s rate, cohesion and angle of internal friction are calculated. The results show that only the elastic modulus has influence, while others have few or no influence on the ground subsidence caused by underground mining in soft rock strata. The agreement of the theoretical results with the field measurement shows that the model is satisfactory and the formulas obtained are valid and this can be effectively used for predicting the movements due to large scale underground excavation in soft rock strata.