地震地质 ›› 2008, Vol. 30 ›› Issue (4): 1033-1045.

• 地震地表破裂带 • 上一篇    下一篇

地表破裂型逆断层地表缩短量计算方法探讨—以汶川MS 8.0地震地表变形为例

王虎, 冉勇康, 陈立春, 史翔   

  1. 中国地震局地质研究所, 国家地震活动断层研究中心, 北京, 100029
  • 收稿日期:2008-11-30 修回日期:2008-12-07 出版日期:2008-12-18 发布日期:2009-11-27
  • 通讯作者: 冉勇康,研究员,电话:010-60229123,E-mail:ykran@263. net.
  • 作者简介:王虎,男,1983年生,2007年毕业于中国地质大学(武汉)地球科学学院地质学基地班,2007年至今在中国地震局地质研究所攻读硕士学位,研究方向为活动构造,电话:010-62009140,E-mail:wanghu9905@126.com.
  • 基金资助:
    国家自然科学基金(40872130);中国地震局汶川8.0级地震应急科学考察项目共同资助

THE DISCUSSION ON THE CALCULATION METHOD OF SURFACE SHORTENING AMOUNT DUE TO REVERSE-FAULTING SURFACE RUPTURE:WITH THE EXAMPLE OF SURFACE DEFORMATION OF THE MS 8.0 WENCHUAN EARTHQUAKE

WANG Hu, RAN Yong-kang, CHEN Li-chun, SHI Xiang   

  1. National Centre of Active Fault Studies, Institute of Geology, China Earthquake Administration, Beijing 100029, China
  • Received:2008-11-30 Revised:2008-12-07 Online:2008-12-18 Published:2009-11-27

摘要: 合理估计逆断层地表破裂缩短量是全面认识同震地表变形参数的核心内容,目前还没有较成熟的方法。以汶川MS 8.0地震地表破裂为例,尝试通过探槽开挖来研究逆断层水平缩短量的计算问题。在分析汶川地震同震变形的基础上,总结了3种陡坎的成因模式:断层断错地表型、挠曲型、断层与挠曲叠加型,并依据这些模型提出了一些水平缩短量的计算方法及其限制条件,以及如何理解逆断层地表破裂探槽开挖所揭示的信息。最后给出了汶川MS 8.0地震白鹿中心学校和汉旺全新村两地点水平缩短量的求解过程及结论,计算得到白鹿中心学校探槽水平缩短量为(2.83±0.3)m,汉旺全新村探槽水平缩短量为(0.61±0.11)m。

关键词: 汶川MS 8.0地震, 逆断层, 水平缩短量, 探槽

Abstract: A reasonable and authentic estimate of surface rupture shortening amount of reverse fault is essential to a thorough understanding of the co-seismic surface deformation parameters,while we have no effective or feasible methods to deal with it,presently.The paper attempts to analyze and calculate horizontal shortening amounts of reverse fault with trench excavation basing on the investigations of the surface ruptures of the MS 8.0 Wenchuan earthquake.On this condition,we conclude three genesis models of fault scarp,namely,faulting,flexuring,and superposition of faulting and flexuring.The paper proposes several calculation methods about horizontal shortening amounts of reverse fault based on these fault scarp models,and also gives detailed mathematic proof and constraint factors when considering complicated phenomena.Moreover,combined with these models,we discuss how to correctly apply and interpret the reverse surface rupture information revealed by trench.Finally,we demonstrate the calculation process and results of the reverse fault's horizontal shortening amounts in the trench close to the Central School of Bailu and the trench at Quanxin village of Hanwang,which are(2.83?0.3)m and(0.61?0.11)m,respectively.

Key words: MS 8.0 Wenchuan earthquake, reverse fault, horizontal shortening amount, trench

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