软硬相间岩层底板变形研究

引入损伤变量ω理论，分析水平状软硬相间岩层在竖向应力下的应力-应变关系：再引用弹性模量E和岩层厚度L两个变形参数建立软硬相间岩层底板变形参数方程，得出竖向应力随着底板深度的增加而减小的规律：运用数值模拟软件，建立煤层开采模型，模拟软硬相间岩层底板在采动作用下的变形过程。通过数值分析底板在采动作用下的应力-应变关系和位移特征，发现竖向应力作用下软岩受到的水平应力比硬岩大，竖向应变也比硬岩大，而竖向应力和水平应变变化不大，认为在采动影响下软硬相间岩层底板中的软岩具有吸收更多的应变能来保护软岩下硬岩的变形特点。

A Study on Alternative Soft and Hard Rock Floor Deformation

The damage variables ω is used theoretically to analyze the stress-strain relationship of horizontal alternative soft and hard layered strata under vertical stress, and use the elastic modulus E and the thickness of rocks L to set up the equation for deformation parameters of alternative soft and hard rock floor. And find out the deeper the coal floor, the less the vertical stress. With the help of numerical simulation software, established coal mining model and simulated the process of alternative soft and hard rock coal floor deformation during coal mining. According to the stress-strain relationship and floor displacement characters, find out that the horizontal stress and the vertical strain infecting on soft rocks is larger than on hard rocks, but the vertical stress and the horizontal strain change a little, as a result the regular pattern of floor deformation is obtained, that is the soft rocks can absorb more strain energy and protected underlying hard rocks. Finally find out results of numerical analysis are consistent with the results of theoretical analysis. The conclusion is helpful in coal mining practice.