CCTEG Coal Mining Research Institute
Mining and Design Branch,China Institute of Coal Science
State Key Laboratory of Coal Mining and Clean Utilization

为深入研究煤矿地应力与埋深的关系,以“中国煤矿应力环境数据库”为数据统计来源,经过数据的转换和筛选,最终选取1147组地应力数据作为研究对象,采用数理统计和力学的方法重点对主应力、三向侧压比、水平剪应力等参数随埋深的变化进行了分析。研究结果表明:(1)1147组实测数据中,逆断型应力状态(σH>σh>σV)占25%,走滑型应力状态(σH>σV>σh)占55%,正断型应力状态(σV>σH>σh)占20%;中低应力区数据较多,占65%以上。煤矿井下三向应力在埋深0~148m时,为逆断型应力状态;在埋深148~1089m时为走滑型应力状态;埋深超过1089m时为正断型应力状态。(2)埋深越小,侧压比分布越离散,取值越大;埋深越大,侧压比越小并最终趋于固定值,平均主应力侧压比Kav趋近0.6,最大主应力侧压比KH趋近0.8,最小主应力侧压比Kh趋近0.4。(3)Kav=1时对应的煤矿“临界深度”为329m,即平均水平主应力与垂直应力相等时对应的埋深为329m。(4)得到了水平剪应力相对大小μm随埋深变化的拟合公式,μm主要集中在0.15~0.35,平均为0.25左右;μm值越大,断层越容易滑动失稳,μm超过0.35的煤矿区域应重点监测其大型断层的稳定性。

A total of 1 147 in-situ stress data sets were selected from "the data of underground coal mine environmental in-situ stress in China" to deeply investigate the relationship between the stress and buried depth of coal mine strata. This study focused on the analysis of the evolution of principal stress,lateral pressure ratio,and horizontal shear stress ( μm ) with buried depth using mechanics and mathematical statistics. The results showed that the proportion of reverse fault stress state ( σH>σh>σV ),strike slip stress state( σH>σV>σh ),and normal fault stress state ( σV>σH>σh ) was 25%,55%,and 20%,respectively. There were many data in the middle and low stress area,accounting for more than 65%. When the buried depth was 0-148 m,the three-dimensional stress in the coal mine was in the state of reverse fault stress. The three-dimensional stress state changed to strike slip stress state when the buried depth was 148-1 089 m. The three-dimensional stress state turned into normal fault stress state as the buried depth was higher than 1 089 m. The shallower of the buried depth,the more discrete the distribution of lateral pressure ratio and the greater of the ratio was. The lateral pressure ratio decreased gradually with buried depth and finally tended to a constant value. The value of Kav,KH,and Kh was about 0.6,0.8,and 0.4,respectively. The "critical depth" of coal mines was 329 m for Kav =1. A fitted formula for the relationship between horizontal shear stress μm and buried depth was proposed in this study. The μm was mainly concentrated between 0.15 and 0.35,with an average of around 0.25. The larger the μm value,the more likely the fault was to slip and became unstable. The coal mines where the μm exceeds 0.35 should be closely monitored for the stability of large faults.

天地科技股份有限公司开采设计事业部基金资助项目(TDKC-2022-QN-05);天地科技股份有限公司开采设计事业部重点基金资助项目(KJ-2022-KCZD-01)