垂直交岔点扰动主应力变化规律及围岩稳定性研究

Study on the change law of disturbance principal stress and the stability of surrounding rock of vertical working intersection

以矿山垂直交岔点为工程背景,通过VB编程对数值分析结果进行二次处理,揭示了与地应力存在不同空间位置关系的垂直巷道交岔点的扰动主应力矢量分布规律(主应力的大小变化和方向偏转);并引入点安全系数法,研究了垂直巷道交岔点围岩变形量和松动圈范围随交岔点空间位置变化的规律。结果表明:扰动主应力矢量主要受原岩主应力的影响,而几乎不受交岔点与地应力空间位置和巷道开挖顺序的影响,扰动主应力由浅部至深部先增加后减小,交岔点顶底板和两帮的最大扰动主应力分别为水平应力和垂直应力;垂直交岔巷道轴线越靠近两水平主应力法向平分线,交岔点围岩变形量和扰动屈服范围越小、围岩稳定性越高,且先开挖更靠近最大水平主应力方向的巷道对交岔点围岩的扰动影响更小。

Taking vertical working intersection in a mine as the background, the distribution law of disturbed principal stress vector（including the value and the deflection rule of the direction of such disturbed principal stress vector） of vertical working intersection, which keeps a different spatial location relationship with the in-situ stress, has been revealed through VB programming to dispose the data of numerical analysis. And the law of both the deformation and loose circle of intersection surrounding rock changing along the spatial location mentioned above has been studied by introducing the method of point safety factor. The result shows that such stress vector is mainly influenced by the in-situ stress but hardly by the spatial location and the excavation sequence of vertical working, and from the shallow of surrounding rock to the deep, the value of such stress vector decreases to in-situ stress after the first in crease; the maximum disturbed principal stress in the roof and floor of intersection is horizontal stress, while such stress in the two sides of intersection is vertical stress; the closer the axes in the vertical intersection is to the two horizontal principal stress normal bisector, the more stable the surrounding rock of intersection is. What is more, the surrounding rock is more stable when the roadway of intersection near the maximum horizontal principal stress is excavated firstly than the other excavation sequence.