principal compressive stress

For the Beijing-Tianjing-Tangshan-Bohai area, the maximal principal compressive stress in depth is of ENE or nearly EW direction.

京津唐渤地区，深部最大水平主压应力方向为北东东向或近东西向。

The direction of compressive principal stress is in NEE and the tensil stress is in NNW.

结果表明,应力场主压应力方向为NEE—SWW方向,主张应力为NNW—SSE方向.

Criteria: ( 1) It is an active fault if the acute angle β between its trend and the direction of the principal compressive stress σ 1 is between 0 ° and 50 °;

其判据为：①某断裂走向与主压应力1σ方向所夹的锐角0°≤β≤50°时，其为活动断裂；

The maximum horizontal direction NE60~ 65 ° of principal compressive stress on Jianghan basin was given by using analytic method of measured stratigraphic dip angle in addition to borehole log data

利用钻孔测井资料并运用地层倾角测量信息分析法，给出了江汉盆地地应力最大水平主压应力方向为NE60～65°

In accordance with the orientation, northeast and north northeast, of principal compressive stress in North China, the dominant orientation of the fast S wave polarization is northeast before the earthquake.

震前快S波偏振优势取向为北东向，符合华北地区主压应力方向为北东向和北北东向的特征。