应用震源机制方法研究鹤岗煤田开采区的构造应力环境

求解鹤岗强矿震震源机制解结果,表现出走滑伴随逆断层和正断层活动、非双力偶型的多样性。两组节面优势分布方向和节面的倾角优势分布不显著,两者分布无明显规律,反映出矿井下破裂面比较复杂。矿震震源主压应力释放优势方向北西310°左右,优势倾角为25°～60°;主张应力轴走向NE,主张应力场优势方向为北东60°左右,仰角在30～70°之间;中等应力轴(N)近于垂直,优势倾角为70～90°。矿震震源机制解显示的矿区最大主应力方向与区域构造应力场的最大主应力方向近似正交,矿震震源机制主应力轴优势倾角远大于区域构造地震,反映的是矿区采煤生产的次生构造应力环境重力应力场的贡献明显。

Study on tectonic stress environment of Hegang coalfield by using focal mechanism method

The Hegang mining earthquake source mechanism solution shows diversity of this non-double-couple earthquake sources.Seismogenic fault slips away while the performance of normal faults and strike-slip reverse fault characteristics of nodal planes is measured.Dominant direction and dip angle of two-node nodal plane are not significant and show the failure surface of the mine complexity.The dominant direction of principal stress release in mine seismic source is NW310° and the dominant dip range is 25°～60°.The strike of principal tensive stress axis along NE and the dominant direction of principal tensive stress field is NE 60°.The elevation angle is between 30°～70° and the secondary stress axis(N) is almost vertical.The dominant dip range is between 70°～90°.The direction of the maximum pricipal stress shown by the focal mechanism method is approximately orthogonal with that of the regional tectonic stress field.The dominant dip angle of principal stress axis of the mining earthquake is far more great than that of the regional tectonic earthquake,which reflects that the contrbution of the secondary tectonic stress to the environment gravity stress field is significant.