顶板应力长期演化规律

介绍了伯格蠕变粘塑性模型,此模型体应变分量和偏应变分量均包含塑性变形部分,这可以有效地模拟永久变形,由于在屈服后体积应变中包含了塑性部分,因此即考虑了屈服后的球应力分量对偏应变的影响。从而使模拟更趋于实际。并以某浅煤层煤矿为例,模拟了顶板应力的长期演化规律,为顶板的支护从时间上给予了解释。指出支护的最佳时间是在工作面前后出现最大压应力时,同时也指出了回填的安全时间。此模型也可模拟其它地下岩体。

Long-term evolution regularity of roof stress

The paper introduces the model of burger creep viscoplasticity briefly, the volumetric strain component and the deviatoric strain component of which both contain plastic deformation and this can simulates efficiently permanent deformation, after yielding the volumetric strain contain plastic part, so the effect of the sphere stress component to the deviatoric strain component is considered after yielding. Then simulation tends to practice. And it simulates long-term evolution regularity of the stress of the roof with a shallow coal mine, and gives an explanation for the roof supporting time. It is pointed out that the best supporting time is when in the front/back of the working plane appears maximum compressive stress. The safe time of backfill is given, too. The model can also simulates other underground rocks.