一、概述井壁崩落法是目前确定深部应力方向的重要方法。钻孔崩落是指沿垂直钻孔对趾部位出现的两条与钻孔平行的崩落带的现象,其结果可导致钻孔横截面成为椭圆形。理论与实验结果均表明该现象为地应力所致,其长轴方向与最小水平主应力S_h的方位一致。钻孔崩落的规模(崩落深度与宽度)与地应力大小有关,其中崩落宽度因受岩性影响而误差较 I. Overview The borehole caving method is an important method to determine the direction of deep stress. Borehole breakage refers to the phenomenon of two bores parallel to a borehole appearing along the vertical borehole toe area, with the result that the borehole cross section becomes oval. Both theoretical and experimental results show that this phenomenon is caused by in-situ stress and its long axis coincides with the orientation of the minimum horizontal principal stress S_h. The size of the borehole caving (caving depth and width) is related to the magnitude of the earth stress, with the width of the caving being more erroneous due to lithology