双鸭山矿区深部地应力分布规律与区域构造作用分析

Analysis on stress distribution law of deep stratum and effect of regional tectonics in Shuangyashan Coal Mining Area

采用空心包体三维应力解除法对双鸭山矿区7个矿井不同开采水平的22个测点进行了地应力实测分析。受多期地质构造运动复合叠加作用的影响,实测所得地应力数据离散型较大,但整体表现为深部属于以水平应力为主,且最大主应力大多在30 MPa以上的σH>σh>σv型高地应力场。最大主应力、侧压系数以及水平差应力整体上均随深度的增加而增大。深部最大主应力方向平均为169.73°,总体趋于NW—SE方向,水平差应力均值为17.52 MPa,主应力回归方程中应力梯度和常数项比值悬殊,表明该区域岩体受剪切作用显著,与现场巷道围岩破碎、巷道动压灾害显现频繁相对应。此外,通过对双鸭山煤田区域构造空间展布特征分析推断得出区域应力场呈"山"字形分布,是长期受近南北挤压力作用而发生力学性质转变的结果,结合区域内地应力实测结果,可作为矿井深部开拓设计和区域动力区划的重要参考。

In-situ stresses are measured at 22 different points in different mining level from seven coal mines of Shuangyashan coal mining area by means of boring stress-relief method with hollow inclusion triaxial strain gauge. Though the stress measurement data discreteness is very great under the influence of the composite superimposition of multi-stage tectonic movement,the horizontal stress is predominate in depth and the value of the maximum horizontal principal stress is more than 30 MPa,the type of stress field belongs to σH〉σh〉σv. The variation of maximum horizontal principal stress,coefficient of horizontal pressure and horizontal differential stress almost linearly increase with depth,average angle of the maximum principal stress direction is 169. 73°,which is almost NW-SE nearly horizontal. The regional rock mass is obviously affected by shear and the dynamic pressure disasters is frequently because the value of average horizontal differential stress is 17.52 MPa and the ratio of stress gradient and constant term is lager in the principal stress regression equation. Furthermore,according to the distribution of tectonic space in Shuangyashan coalfield,the geologic stress distribute in ＂ mountain＂ glyph which was made by the north-south extrusion in long time. Combined with the results of in-situ stress,it can be used as an important reference for deep mining design and regional dynamic zone.