基于有限元分析的大包庄矿地表移动带圈定

选取大包庄矿开采范围内所有地质剖面, 建立二维有限元数值模型, 计算一期、二期工程矿体开挖后不充填和全充填2种工况下的地表变形, 通过地表变形值与标准值对比, 圈定2种工况下的地表移动带, 并对数值模拟法与工程类比法圈定的移动带进行了对比分析。结果表明: 采空区不充填时数值模拟法与工程类比法圈定的范围较接近, 开挖矿体较薄时, 数值模拟法计算的地表移动范围在工程类比法确定的移动范围内；开挖矿体较厚时, 数值模拟法计算的地表移动范围在工程类比法确定的移动范围外。采空区全充填时数值模法与工程类比法圈定的移动带范围差异较大, 充填体限制了围岩变形, 减小了地表移动范围。数值模拟法充分考虑了矿山复杂地质条件和开采技术条件, 其圈定的移动带能更好地反映实际地表变形。

Delineation of Surface Displacement Belt for Dabaozhuang Mine Based on Finite Element Analysis

A two-dimensional finite element numerical model was established with all geological sections of Dabaozhuang Mine within the scope of exploitation, with which surface deformation was calculated for phase I and phase II projects after an excavation of orebody with and without backfill. Based on the comparison between surface deformation value and standard value, surface displacement belts under the above two working conditions were delineated. Then, the obtained displacement belts were compared with those obtained by engineering analogy method. Results show that, as for mind-out area without backfill, the displacement areas delineated by two methods are similar. The displacement belt obtained by numerical simulation method is included in the displacement scope obtained by engineering analogy method for the excavation of thin orebody, but out of the displacement scope for excavation of thick orebody. As for the mind-out area being backfilled, there's a big difference between the surface displacement scope obtained by the above two methods, because the backfill restricted the deformation of surrounding rock, resulting in a displacement scope reduced. It is concluded that the displacement belt delineated with numerical simulation method can give a better reflection of the practical surface displacement situation due to the complex geological conditions and existed mining technology being taken into a full consideration.