地震共轭破裂及极限主应力随地壳深度的变化——以1975年海城7.3级地震为例

许多震例表明，地震可以形成共轭破裂，地震震源处，其温度和压力与地壳浅处及地表不同，温，压越高，共轭破裂角越大。随着深度的变浅（温，压减小），地震共轭破裂角减小，地震烈度共轭角也减小，本文用数学力学方法和岩石力学实验结果，探讨了海城地震共轭破裂及极限主应力随地壳深度的变化。

Seismic Conjugate Ruptures and Limiting Principal Stresses Accompa nying Variation of Depths in the Crust -Take 1975 Haicheng Earth quake with M7.3 as an Example

Many examples show that earthquakes can form conjugate ruptures. The temperature and pressure at the focus is different from the shallow of the crust and the ground. The higher temperature and pressures, the larger conjugate rupture angle. Accompanying decrease of depths, temperature and pressure become small and the conjugate rupture angles also become small. The conjugate angles of isoseismic lines on the ground also become small. The pure shear ruptures easy appear at the focus. The tension shear ruptures easy appear near shallow places of the crust from the focus upward. It discusses the conjugate ruptures of the Haicheng earthquake and its limiting principle stresses accompanying variation of depths in the crust by mathematic mechanics methods and the result of rock mechanics experiments.