依据滑动准则、原地应力测量讨论红河断裂的北段地震活动性

A Discussion on the Seismic Activity of the Northern Segment of the Honghe Fault in Accordance of the Slide Criterion and in-situ Stresses

一、引言在地震研究中,自粘滑运动作为地震的一种机制解释以来,地震工作者对岩石摩擦的研究十分重视。根据原地应力测量结果和地应力场的分析,得到断层面上各处的应力状态,就可以用断层滑动准则判断断层的稳定性.J.D.Byerlee根据大量实验室资料分析和M.D.Zoback与J.Healy在野外断层上的验证,认为断层面的摩擦系数μ=0.6~1.0较为合适。断层滑动准则可用τ=(0.6~1.0)σ_n来表示。式中τ是断层滑动的临界剪切应力,σ_n为断层面上的正应力。

The experiment of frictional behavior of gneiss have been carried out using the double shear and triaxial test equipment.The maximum normal stress on the glide plane is^about 190 MPa.The experimental result shows that the maximum friction between the gneiss smooth surface can be roughly expressed by x=(0.58~1.01)where x is the maximum shear stress which the sliding surface can bear,and anis the normal stress in the sliding surface.If there is fault gouge between the sliding surface,the slide is always stable,and the maximum friction can be expressed byτ=(0.6~1.0)σ_n.If the stress state at a fault surface and the sliding criteria of a fault were known,the stability of such fault could be estimated quantitatively.