基于三维地应力测量的岩爆预测问题研究

岩爆预测中常用的动态指标切向应力σθ是与初始地应力场密切联系的。根据开阳磷矿实测三维地应力值和该矿多层岩体赋存的特点,分析了洞室围岩岩性、空间巷道、倾斜层理等因素对σθ的影响。开阳磷三维地应力测试成果表明,埋深浅的砂岩比埋深大的红页岩的垂直地应力值要大近3倍,提出了考虑测点岩性的地应力场区域应用观点和考虑巷道轴向空间性的三维地应力空间分解方法。按上述方法,通过数值模拟研究发现,考虑倾斜层理时发生岩爆的位置主要在右帮底部。这与马路坪矿现场观测的破坏结果较吻合。区域空间分解法的岩爆预测结果比线性拟合回归法更接近实际。

Study of forecast of rock burst based on three dimensional in-situ stress measurement

In rock burst forecast tangential stress ?θ is a dynamic index closely related to initial in-situ stress field. According to the results of three-dimensional in-situ stress measurement and occurrence features of multilayer rockmass in Kaiyang Phosphate Mine, some problems of surrounding rock property, space tunnel, inclined bedding, etc. influenced tangential stress ?θ are analyzed. Its initial in-situ stress field shows that the measurement values in sand stone is about 3 times larger than that of red shale though red shale is buried deeper than sandstone. Considering the lithology of measuring points, the viewpoint of region application of initial in-situ stress field is accordingly proposed; similarly, the space decomposition method of in-situ stress is correspondingly put forward to adapt to the spatiality of laneway axial direction. According to above-mentioned methods, numerical simulation indicates that when inclined bedding is taken into account rock burst location is mainly side foot which almost accords with the rock burst in field. Rock burst forecast by region application and space decomposition method is closer to actual case than by linear fitting regression method.