太原盆地应力场演化与强震关系的数值模拟研究

发布时间：2018-10-09 11:33

【摘要】：近年来,太原盆地内尽管没有强震发生,小震却异常活跃,而研究太原盆地构造应力场的分布和演化规律的工作比较少.采用有限元数值方法,综合考虑区域地质构造差异、主要活动断裂带、地形起伏和岩石圈分层结构,引入深部速度结构,建立包含太原盆地在内的山西地区三维粘弹性模型.以GPS观测值和最大主压应力方向测量值为约束条件,重建研究区现今构造背景应力场.在此基础上,依次模拟了自公元512年以来太原盆地6级以上和山西地震带7级以上历史强震序列.计算结果显示,太原盆地内的3次6级以上历史地震均落在应力场增加值大于0.01MPa的区域,盆地近年来小震空间分布与现今应力增加值大于0.01MPa的区域有较好的对应关系.研究表明:山西地震带内历史强震序列和长期构造加载对太原盆地内3次历史强震均有促进作用,太原盆地的地震活动性明显受区域当前应力水平的控制.
[Abstract]:In recent years, although there are no strong earthquakes in Taiyuan basin, small earthquakes are very active, but there is little work to study the distribution and evolution of tectonic stress field in Taiyuan basin. A 3-D viscoelastic model of Shanxi region including Taiyuan basin is established by introducing deep velocity structure into consideration of regional geological structure difference, main active fault zone, topographic fluctuation and lithospheric stratification structure by using finite element numerical method. Based on the GPS observations and the maximum principal compressive stress direction measurements, the present tectonic background stress field in the study area is reconstructed. On this basis, historical strong earthquake sequences of M 鈮，

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