地震学报
地震學報
지진학보
ACTA SEISMOLOGICA SINICA
2014年
6期
1010-1021
,共12页
连尉平%李丽%唐方头%胡彬%李晓璇
連尉平%李麗%唐方頭%鬍彬%李曉璇
련위평%리려%당방두%호빈%리효선
汶川 Ms 8.0 地震%龙门山断裂带%平行逆断层%地震活动性%有限元分析
汶川 Ms 8.0 地震%龍門山斷裂帶%平行逆斷層%地震活動性%有限元分析
문천 Ms 8.0 지진%룡문산단렬대%평행역단층%지진활동성%유한원분석
Wenchuan Ms 8.0 earthquake%Longmenshan fault zone%parallel thrust fault%seismicity%finite element analysis
本文构建一种应用有限元开展特征地震数值模拟的新方法,并以龙门山断裂带中段的浅层构造和动力学机制为背景,研究了平行逆冲断层分布格局对区域地震活动性的影响。结果表明,从断层活动相互影响的角度看,包含3条平行逆断层的断裂带的整体地震活动性并不适用严格周期的特征地震模型,当断层间距在20 km 以下时,随着断层间距的缩短,对单条断层应用特征地震模型的适用性会逐渐降低。龙门山断裂带中段的模拟计算结果显示,后山断裂的地震活动相对独立,区域活动性和中央断裂的断层活动很可能不适用严格周期的特征地震模型。
本文構建一種應用有限元開展特徵地震數值模擬的新方法,併以龍門山斷裂帶中段的淺層構造和動力學機製為揹景,研究瞭平行逆遲斷層分佈格跼對區域地震活動性的影響。結果錶明,從斷層活動相互影響的角度看,包含3條平行逆斷層的斷裂帶的整體地震活動性併不適用嚴格週期的特徵地震模型,噹斷層間距在20 km 以下時,隨著斷層間距的縮短,對單條斷層應用特徵地震模型的適用性會逐漸降低。龍門山斷裂帶中段的模擬計算結果顯示,後山斷裂的地震活動相對獨立,區域活動性和中央斷裂的斷層活動很可能不適用嚴格週期的特徵地震模型。
본문구건일충응용유한원개전특정지진수치모의적신방법,병이룡문산단렬대중단적천층구조화동역학궤제위배경,연구료평행역충단층분포격국대구역지진활동성적영향。결과표명,종단층활동상호영향적각도간,포함3조평행역단층적단렬대적정체지진활동성병불괄용엄격주기적특정지진모형,당단층간거재20 km 이하시,수착단층간거적축단,대단조단층응용특정지진모형적괄용성회축점강저。룡문산단렬대중단적모의계산결과현시,후산단렬적지진활동상대독립,구역활동성화중앙단렬적단층활동흔가능불괄용엄격주기적특정지진모형。
This paper constructs a finite element analysis (FEA)method for the numerical simulation of characteristic earthquakes,based on the wide-accepted knowledge of the shallow crustal structure and dynamic boundary conditions at the middle part of the Longmenshan fault zone.The influence of parallel thrust faults on regional seismic activity is focused on and simulated with this FEA model.The results show that the characteristic earthquake model with strict re-currence interval is not suitable for the entire fault zone which contains three parallel faults.When the distance between the faults is less than 20 km,the applicability of the characteristic earthquake model to each single fault is attenu-ated with the distance between the faults decreasing.The results based on the distribution pattern of the profile in the middle of the Longmenshan fault zone reveal that seismic activity of the back range fault is relatively independent,and the characteristic earthquake model with strict recurrence interval is not suitable for the entire fault zone and the central fault.