构造应力方向与断层能动度

TECTONIC STRESS ORIENTATION AND FAULT CAPABLE DEGREE

文章应用应力摩尔圆分析法，探讨了三维空间状态下断层能动度与构造应力方向和断层面几何特征的关系。分析结果表明：断层面法线与最大主压应力方向间的夹角θ在大于断层内摩擦角φ和小于π／２时，断层可能产生滑动；当θ角等于４５°＋φ／２时，断层最易滑动。在此基础上，将断层能动度进行数值化。华北地区１９６６至１９７６年４次强震区的活动断层研究结果，与理论分析结果相符。

The paper approaches the relationship among fault capable degree,toctonic stress orientationand geometric characteristics of fault plane in three dimensions by the method of Mohr stress circle.The analytic result shows that when angle θ between orientation of maximum compressive stress andnormal line of fault plane is between larger than fault inner frictional angle ac and smaller than 90°,thefault may slip;when angle θiS 45°+Φ/2, the fault is most likely to move. On the basis of above, faultcapable degree is digitized. The research result of the active faults in the areas of 4 strong earthquakesin North China from 1966-1976 agrees with the theoretic model.