淮南矿区地应力场特征

Characteristic of in-situ stress field in Huainan mining area

利用空心包体地应力测量方法对淮南矿区的地应力进行了实测,获得了矿区的地应力场分布特征。研究表明,所有测点的两个主应力近水平,一个主应力近垂直。垂直主应力与上覆岩体的重力具有良好的相关性;水平主应力随深度的增加而增加,不同区域增加的梯度不同;最大水平主应力与最小水平主应力的比值与测点深度没有明显的关系,50%以上测点的水平主应力差异显著;最大水平主应力作用方位为北东向,局部受构造等影响,水平主应力发生变化。总体上,淮南矿区受北东向的挤压应力作用。根据3个主应力量值的关系,确定淮南矿区地应力场类型属大地动力场型和准静水应力场型。地应力场的以上特征对淮南矿区煤与瓦斯突出的发生具有重要作用,提出了在进行瓦斯抽放钻孔参数设计时应考虑地应力场特征的建议。

The hollow included technique was used to measure the in-situ stress of Huainan mining area. According the analysis of the measurement data, the characteristic of in-situ stress field is obtained. The result shows that： （1） two principal stresses are nearly horizontal and one is nearly vertical among three principal stresses on all sites. The magnitude of vertical stress is equal to the weight of overburden rock mass. The horizontal principal stress increased with the depth; （2） The ratio of major principal stress to minor principal stress did not increase with depth evidently, the difference between major principal stress and minor principal stress is large on 50% sites; （3） The orientation of major principal stress is NE, there is some deflection localy. According to the relation of three principal stresses, the type of Huainan mining area is dynamic stress field and quasi static stress field. In-situ stress field plays a important role in coal and gas outburst in Huainan mining area. It was suggested that in-situ stress field should be considered during the gas drainage design.