Based on the theories of tidal stress, structural stress, seismic faults, rock fracture and slip, the mechanical modal of tidal stress effects o seismic faults is set up. Combining tidal stress with seismic stress, the modal describes the ways of mechanical effects on seismic faults by tidal stress components along seismic compressive principal stress and extensional principal stress, thereby, the mechanism on tidal triggering of earthquake be touched. The tidal triggering effect on earthquakes actually belong to the slip acceleration effect of tidal stress on seismic faults. The patterns of the effect are classified into compression-adding type and compression-reducing type. On the basis of the modal, the tidal triggering characteristics of earthquakes in China and its neighbor area are studied. The studies include following contents. Tidal stress components along P axis T axis of more than one thousand earthquake focuses distributed in China and its neighbor areas are calculated. Patterns of tidal stress effect on the earthquake faults are analyzed. Statistics of seismic fault types related with slip-accelerating effect of tidal stress and relationship between the types and the patterns are made for various latitude areas. The following features are obtained: Proportion of the numbers of seismic faults related with the slip-accelerating effect of tidal stress has decreasing trend with latitudinal rising. Among them, proportion of the strike-slip faults in low latitude area is comparatively large but that of the dip-oblique-slip faults in middle high latitude area is comparatively large. For the whole area, proportion of the numbers of seismic faults affected by the compression-adding type is larger than that affected by the compression-reducing type. For different latitude areas, various patterns of tidal stress effects and relevant types of seismic faults have various distributing features. At last, the earthquakes in China and its neighbor area suffered by tidal triggering effects are divided according to structural stress areas. The lunisolar location parameters on the times of the earthquakes are calculated and the distribution patterns of the lunisolar location parameters are obtained.
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