基于FLAC^3D模拟的大规模采空区破坏概率研究

Failure probability of goaf in large-scale based on simulation of FLAC^(3D)

采空区稳定性的问题由来已久,但目前对采空区的整体稳定性评价结论几乎仍停留在定性层面上,特别是对于条件复杂的大规模地下矿山采空区,若能将其量化则在很大程度上将会对矿山安全提供一定的保障。针对大规模采空区稳定性的难题,在数值模拟的基础上引入采空区破坏概率的概念试图解决这一问题。在FLAC3D后处理的过程中,结合统计学中概率的基本原理,利用Excel的风险分析插件@Risk对FLAC3D网格单元的计算结果进行统计分析,并以95%的置信区间为准,从主应力、剪切破坏判据Fs以及弹性应变能等方面深入研究分析采空区的破坏概率,进而将采空区稳定性问题得以量化,同时得出了大量岩石网格单元主应力和弹性应变能分布服从韦布尔分布(Weibull)和对数正态分布(lognorm)的规律。量化不仅解决了空区稳定性的问题,也将为数值模拟开拓更为广阔的应用空间。

Goaf stability is a long-standing problem. But almost all conclusions about goaf-integral-stability-evaluation are on a qualitative level, especially for the goaf in condition of large-scale and complex underground mines. If be quantified, it will, to a better extent, provide some protections for mine safety. For the problem of goaf stability in large-scale, the concept of “failure probability of goaf”based on numerical simulation is introduced to try to answer it. In the postprocessing of FLAC3D, several aspects of failure probability of goaf in the principal stress and shear failure criterion Fs and elastic energy are researched and analyzed respectively, in which the basic principles of probability of statistics are subjected to 95% confidence interval, and＆quot;Excel＆quot;plugin@Risk is used to statistically analyze the calculation results of grid in FLAC3D; then it makes the stability problem of goaf been quantified. Finally, a conclusion that the principal stresses and elastic energy of rock grid cells in large number follow Weibull distribution and Lognormal distribution has been drawn as well. At the same time, quantification not only solves the problem of the goaf stability, but also makes application of numerical simulation broadened.