摘要
通过对地震震源处沿主压应力P轴和主张应力T轴方向的附加潮汐应力分量的计算 ,在岩石力学莫尔—库仑准则的基础上分析了附加潮汐应力对发震断层的作用方式。分析和计算表明 ,对发震断层有促滑作用的附加潮汐应力作用方式分增压型和减压型 ,增压型潮汐应力增大断层面上的正压力和剪应力 ,促使断层达到破裂滑动条件 ,减压型潮汐应力在一定条件下能降低断层面上的破裂滑动强度 ,同样能促使断层的运动。计算实例显示 ,大部分发震断层受到了附加潮汐应力的增压型或减压型促滑作用。
Through calculating additional tidal stress component along the P axis of principle compressional stress and the T axis of principle extensional stress at source,the action mode of additional tidal stress on seismogenic fault is analyzed on the basis of Mohr-Coulomb criterion.Analysis and calculation show that the action mode of additional tidal stress on seismogenic fault can be classified as compression increase and compression decrease;the tidal stress for compression increase increases normal pressure and shear stress on the fault plane,which makes the fault be in the state of rupture and slip;the tidal stress for compression decrease can decrease rupture-slip strength on the fault plane under given conditions and also promote the fault's motion.the calculation example shows slip-promoting action of pressure increase or decrease mode of additional tidal stress on the most of seismogenic faults.
出处
《地震研究》
CSCD
北大核心
2001年第1期48-54,共7页
Journal of Seismological Research
关键词
地震主应力
附加潮汐应力
增压型
减压型
促滑作用
发震断层
Seismic principle stress
additional tidal stress
pressure increase mode
pressure decrease mode
slip-promoting action
seismogenic fault
