【作者】 吴梦遥；

【导师】 赵纪生；

【作者基本信息】 中国地震局工程力学研究所 ， 岩土工程， 2012， 硕士

【摘要】 地震中发震断层两侧岩体相对滑动有时会引起非发震断层的位错现象。汶川地震震后科考资料显示这次地震中也可能发生了这一现象：除了在本次地震中活动的中央断裂带映秀—北川断裂和前山断裂带安县—灌县断裂外，在前山断裂带江油—广元断裂和后山断裂带汶川—茂县断裂沿线分布有多个地表破裂点。出现这种现象是由于岩体—非发震断层系统在发震断层两侧岩体相对滑动的扰动下产生了相应的动力响应，如果这种响应过大，非发震断层两侧岩体就会沿断层面产生错动，在地面上表现为地表破裂。非发震断层的错动对场地震害分布有一定的影响，至于是否也会对场地地震动产生影响则尚无定论。一般认为，岩石块体沿发震断层面的粘滑过程体现了地震发生机制。基于唯象学的速率与状态依赖性摩擦本构关系(RSF本构关系)可以很好地解释发震断层面上的粘滑现象。对建立在RSF摩擦本构关系上的岩体—断层系统的摩擦滑动特性的研究为非发震断层对震害及地震动的影响提供了一个思路。为了分析汶川地震对附近非发震断层的影响，本文展开了以下工作：1．介绍了速率与状态依赖性摩擦本构关系的两种形式—滑动本构关系和慢度本构关系；利用慢度本构关系分析了微小扰动下岩体—断层系统稳定性并给出了微小扰动下岩体—断层系统摩擦滑动的稳定性条件；通过一个算例分析不同参数对系统稳定性的影响。2．利用鲜水河断裂两侧五个台站的汶川地震主震加速度记录、场地条件科考中的大康镇建筑物震害数据和地震应急科考中湔底地表破裂数据，初步分析了汶川地震对江油—广元断裂和对湔底山前断裂的影响。3．建立了大康区域和湔底区域岩体—断层二维模型，采用静力方法，考察了发震断层两侧岩体相对运动对包括江油—广元断裂和对湔底山前断裂在内的非发震断层的影响。更多还原

【Abstract】 The sliding of rock mass on both sides of a causative fault sometimes causes thenearby non-causative faults’ dislocation.This phenomenon was proved by the post-quakeinvestigation of Wenchuan earthquake,which showed that there was several surface rupturepoints along the Jiangyou-Guangyuan fault and the Wenchuan-Maoxian fault, in addition tothe Yingxiu-Beichuan fault in the Central fault zone and the Anxian-Guanxian fault in thePiedmont fault zone. Relative to a certain degree of influence on site distribution ofearthquake damage, Non-causative faults’ dislocation has an inconclusive impact ongroundmotion.It’s generally acknowledged that stick-slip process between rock mass along aseismogenic fault refects the mechanism of an earthquake. Recent research indicates thatthis process could be well explained by the rate-and state-dependent friction law(RSF law)based on phenomenological opinions.In order to analyze the impact of the Wenchuan earthquake on the nearby non-causative faults, the paper carries out the following work:1. Describes the two forms of the RSF law,the slip law and the slowness law;Deducethe stability condition of an rock-faults system under a small perturbation by using theslowness law,and then a numerical example would be provided to discuss the influence ofparametres’variation.2. Preliminary analyzes the Jiangyou-Guangyuan fault and the Jiandi piedmont fault’sstates caused by Wenchuang earthquake,using the data of several seismostations’acceleration records in the main shock of Wenchuan earthquake,Dakang town’s buildingearthquake damage data and Jiandi area’s surface rupture data.3. Bulids two-dimensional ABAQUS models of Dakang area and Jiandi area,and thenstudies the dislocation response of the non-causative faults caused by the sliding of rockmass on both sides of Wenchuan earthquake’s causative faults.更多还原