不同应力状态下钻孔孔周变形规律研究

采用COMSOL数值模拟软件,建立三维矩形巷道钻孔交叉模型,研究不同地应力影响下的钻孔孔周应力分布及位移随钻孔深度的变化情况。研究表明：通过分析不同地应力作用下钻孔孔周的Mises应力分布,得到钻孔的左右两侧受压应力,上下两侧受拉应力,呈现出“蝴蝶状”。通过数值模拟及现场试验表明,由于钻孔受到上覆岩层应力及巷道应力重分布的影响,在距离孔口0～20m的范围内即巷道宽度的2倍左右,极易产生钻孔破坏。通过对不同地应力作用下钻孔孔周的应力分布以及位移变化分析,钻孔孔周应力及位移随孔深增加呈现出较强的幂指数关系。

The deformation law of borehole under different stress state is studied

The COMSOL numerical simulation software was used to establish a three-dimensional rectangular roadway borehole crossover model to study the circumferential stress distribution and displacement of the borehole under the influence of different ground stresses. The research shows that by analyzing the Mises stress distribution around the borehole under different ground stresses, the compressive stress on the left and right sides of the borehole is obtained, and the upper and lower sides are subjected to tensile stress, showing a "butterfly shape". Through numerical simulation and field test, it is shown that the borehole is affected by overburden rock stress and roadway stress redistribution, and it is easy to produce borehole damage within the range of 0~20m from the orifice, which is about twice the width of the roadway. By analyzing the stress distribution and displacement variation of the borehole under different earth stresses, the circumferential stress and displacement of the borehole exhibit a strong power exponential relationship with the increase of the bore depth.