中国大陆金属矿区实测地应力分析及应用

摘要

Based on the measured in-situ stress data of the metal mining area in China, 165 sets of data were finally adopted after optimized treatment, which basically covers the distribution area of the main metal mines in the Chinese mainland. The characteristics of in-situ stress field in the buried depth of the metal mining area in China were presented by regression analysis method, and the sta-bility of the fault of the metal mining area in China was discussed from the ground stress. The results show that the vertical principal stress, the maximum horizontal principal stress and the minimum horizontal principal stress in the metal mining area of Chinese main-land generally increase linearly with the depth. The difference between maximum and minimum horizontal principal stresses (Δσ) in-creases with the depth, but the regularity is not significant. The ratio of maximum horizontal principal stress to vertical principal stress ( Kh,max ) , the ratio of minimum horizontal principal stress to vertical principal stress ( Kh,min ) and the ratio of average horizontal stress to vertical principal stress (Kh,av) mainly concentrate in the interval of 1. 00 to 2. 50, 0. 50 to 1. 50, and 1. 00 to 2. 00, respectively. With the increase of depth, the variation amplitudes of the three lateral pressure coefficients decrease gradually: Kh,max , Kh,min and Kh,av tend to 1. 83, 0. 80 and 1. 31, respectively. The ratio of maximum horizontal principal stress to minimum horizontal principal stress has no obvious regularity with the depth, and the values mainly concentrate from 1. 5 to 2. 0, approximate to normal distribution. Metal mining area has the possibility of fault slip when the depth is less than 500 m, and the reverse fault has the possibility of sliding while the strike slip fault is in a relatively stable state when the depth is more than 500 m.%以迄今为止查阅到的中国大陆金属矿区实测地应力数据为基础,经优化处理后最终采用165组数据,基本覆盖了我国大陆主要金属矿山分布地区.采用回归分析法给出了中国大陆金属矿区测量埋深范围内的地应力场特征,并尝试从地应力的角度对中国大陆金属矿区断层的稳定性进行了讨论.结果显示,中国大陆金属矿区垂直主应力、最大与最小水平主应力总体上随埋深呈线性增加;最大与最小水平主应力之差Δσ随埋深的增加有增大的趋势,但规律性不显著;最大水平主应力与垂直主应力之比Kh,max主要集中在1.00~2.50之间,最小水平主应力与垂直主应力之比Kh,min主要集中在0.50~1.50之间,平均水平主应力与垂直主应力之比Kh,av主要集中在1.00~2.00之间,随着埋深的增加,3个侧压系数的变化幅度逐渐减小,Kh,max趋向于1.83,Kh,min趋向于0.80,Kh,av趋向于1.31;最大与最小水平主应力之比与埋深没有显著的关系,主要集中在1.5~2.0之间,近似服从正态分布;断层在埋深小于500 m范围内有滑动的可能,埋深超过500 m时,逆断层有滑动的可能,走滑断层处于相对稳定状态.