【作者】 罗国富；

【导师】 杨明芝； 马禾青；

【作者基本信息】 中国地震局兰州地震研究所 ， 固体地球物理， 2006， 硕士

【摘要】 本文以应力释放模型为基础,为研究大震增(减)震问题对模型提出改进。引入断裂力学裂纹周边应力和应变场理论中的应力函数,从力学角度研究震源与空间任意一点应力的变化特征,找出大震断裂带的其它段落以及平行断层之间的应力变化规律与大震增(减)震作用之间存在的关系,建立起大震增(减)震模型,称为应力释放增(减)震模型。该模型可对一个构造区域发生大震后的地震危险性进行估计,其研究结果对地震预报和地震危险性评价具有较重要的意义。文中应用应力函数和应力释放增(减)震模型对宁夏地区有历史记载以来的5级以上中强地震作了具体研究,研究认为:宁夏北部的贺兰山东麓断裂1739年发生的8级地震,对与其大致平行的芦花台断裂、银川—平罗断裂和黄河断裂起到了明显的减震作用;宁夏南部的海原断裂1920年发生81/2级地震,对与该断裂大致平行的香山—天景山断裂、烟筒山断裂以及牛首山—罗山断裂也起到了明显的减震作用,同时,对祁连山断裂带中东段起到了增震作用。本文最后应用应力函数和应力释放增(减)震模型探索性地研究了2004年印尼8.7级大震的影响。结果表明该大震对苏门答腊断层的其他段落起到了增震作用,而对欧亚板块边界的影响较小。我国位于欧亚板块边界以北,因此该大震对我国影响不大。更多还原

【Abstract】 Based on the Stress Release Model, this article has improved the model in order to study the strong earthquake increase (decrease) earthquake problem. The stress function of stress and strain field theory around a crack in Rapture Mechanics has been introduced. From the angle of mechanics, the stress change features of an epicentre and in any point in space have been studied. The existent relations between the stress change rule and the strong earthquake increase (decrease) earthquake function of the other sections on a fault zone and among parallel faults. The strong earthquake increase (decrease) earthquake model has been built and called the Increase (Decrease) Earthquake Model Based On Stress Release. The model can estimate the earthquake risk after a strong earthquake occur in an structure area and the study results have relatively important significance for earthquake prediction and the earthquake risk estimate.In this article, the idiographic study about Ms≥5 moderately-strong earthquakes recorded since there had the historical records in Ningxia area has been done by using the stress function and the Increase (Decrease) Earthquake Model Based on Stress Release. The results have showed that: That the East Side Helanshan Fault in north Ningxia occurred a 8.0 magnitude earthquake in 1739 has played the obvious decrease earthquake function on the Luhuatai Fault, the Yinchuan-Pingluo Fault and the Yellow River Fault which approximately parallel to the East Side Helanshan Fault. And that the Haiyuan Fault in south Ningxia occurred a 81/2 magnitude earthquake in 1920 has also played the obvious decrease earthquake function on the Xiangshan-Tianjingshan Fault, the Yancongshan Fault and the Niushoushan-Luoshan Fault which approximately parallel to the Haiyuan Fault and at the same time, the increases earthquake function on the Middle East Section of the Qilianshan Fault Zone.At last, this article has studied exploringly the influence of Indonesia 8.7 strong earthquake occurred in 2004 by using the stress function and the Increase (Decrease) Earthquake Model Based on Stress Release. The results have showed that this strong earthquake has played the increase earthquake function on the other sections of the Sumatra更多还原