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在潮汐库仑破裂应力计算和相关性检验的基础上,采用速率-状态依赖性摩擦本构关系,进行潮汐应力对宁洱地震震源断层成核失稳过程影响的数值模拟研究,并讨论潮汐正应力和潮汐剪应力在潮汐应力触发中的作用,以及应力的振幅和周期振荡性对潮汐触发的影响.结果发现,宁洱地震与潮汐应力之间存在潮汐触发相关性.宁洱地震震源断层的成核过程存在一个转变周期,当潮汐应力周期接近和大于转变周期时,潮汐应力的周期性将直接影响潮汐触发作用的效果.潮汐应力振幅值的增加也有助于潮汐应力对断层地震成核失稳过程的影响,正应力和剪应力振幅值的影响效果差别不大,但是潮汐剪应力比正应力能更迅速的起到潮汐触发作用.潮汐应力触发地震的过程中,主要是正值的潮汐正应力和剪应力对地震起到触发作用,而负值的潮汐应力对断层的影响小于正值的潮汐应力,断层对负的潮汐应力不敏感.
Based on the calculation of tide Coulomb failure stress and the correlation test, the numerical simulation of the influence of tidal stress on the nucleation instability process of the source fault of Ning’er earthquake is carried out by using the rate-state dependent friction constitutive relationship. The tidal normal stress And the effect of tidal shear stress on the tidal stress triggering, and the influence of the amplitude and periodic oscillation of the stress on the tidal triggering. It is found that there is a tidal triggering correlation between the Ning’er earthquake and the tidal stress. The periodicity of tidal stress will directly affect the effect of tidal triggering when the period of tidal stress is close to and greater than the transitional period.The increase of tidal stress amplitude also contributes to the destabilization of tidal stress The influence of the process, normal stress and amplitude of shear stress have little difference, but the tidal shear stress can trigger the tide more rapidly than the normal stress.When the tidal stress triggers the earthquake, the tidal positive Stress and shear stress can trigger earthquakes, while negative tidal stress has less effect on the fault than positive tide Stress, faults are not sensitive to negative tidal stress.