节点文献

位错模型模拟昆仑山断层不均匀错动引起的地面变形

Ground Deformation Due to Asymmetric Slip of the Kunlun Fault Simulated by Dislocation Model

【作者】 赵大江

【导师】 张永志;

【作者基本信息】 长安大学 , 大地测量学与测量工程, 2008, 硕士

【摘要】 断层活动诱发了地震,地震是断层活动的一种表现。一次次地震的发生促成了断层的生长与发展,造成了地面破裂、变形和多种严重的灾害。地面大幅度隆起、陷落、山体滑坍移位,田园、道路被切错,建筑物倒塌破裂,令人触目惊心;凡断层经过的地段地震灾害明显加重,给人类带来极其严重的灾难。断裂带的活动是引发地震的“元凶”,地震产生的地表破裂是造成建筑物的破坏以及人类生命财产损失的重要原因。因此,断层错动的研究有助于了解和认识地球内部的动力学过程,探索地震孕育、发生过程,预测地震危险性,最大限度的减轻地震灾害。本文以东昆仑断裂带为背景,详细分析了东昆仑断裂带的地质构造背景;介绍了位错理论的发展和Okada位错理论模型的基本理论和应用原理;并综合东昆仑断裂带的地质地理环境,应用位错理论对均匀滑动模型和不均匀滑动模型在地面引起的形变场进行计算,分析研究;运用C语言进行程序设计,结合GMT(generic mapping tools )中断层的有关参数及该区域地质、地球物理资料,对东昆仑断裂带进行正演解算和模拟,将计算结果运用GMT软件处理,得到了该区域的均匀位错和不均匀位错水平形变和垂直形变模拟场,取得了较好的结果。综合地质,地球物理结果分析断层活动与地面形变的关系,得到的主要结论为:1.东昆仑活动断裂带具有明显的破裂分段特征,不同段落的活动水平存在一定差异,断裂垂直位移分量小,整条断裂以左旋走滑为主。2.断裂带普遍具有羽列组合和局部走向突变等结构特征,沿断裂带走向出现了几个位移峰值,断层错动的不均匀性在位错阶区产生垂直形变隆起区或下沉区。3.通过均匀分布与不均匀分布模型计算可知,断层面上的地面位移场在走滑方向的近场变形差异最大,在垂直于断层走向的变形差异次之,在垂直于地面方向的变形差异最小。上述观点与现实的特征情况表现出较好的一致性,取得了较好的成果,证明了位错理论模型在断层错动与地面形变关系研究应用中的可行性。

【Abstract】 Fault activity induces the earthquake and the earthquake is a kind of a performance of fault activity. Time and time again,the earthquake contributs to the growth and development of fault,causes the ground rupture,deformation and many kinds of serious disasters.Ground elevates and collapses dramatically,it also causes landslide and shift,pastoral and roads were offset,the buildings collapsed,it is a ghastly sight.The earthquake disaster is intensified significantly in the case of having faults,it brings mankind much more serious disaster. The activity of the fault zone is "culprits" which triggers earthquake,the ground rupture generated by the earthquake is the key reason that result in heavy damage to buildings and losses of life and property of humanity.Therefore,the study of faulting will help to understand the internal dynamics of the Earth,explore the earthquake preparation process, predict earthquakes risk, and maximize the of earthquake disaster reduction.In this paper,based on the east Kunlun fault zone, we analyze its’geological structure background in detail; introduce dislocation theory including its development, and Okada elastic half-space theory model;calculate and study ground deformation caused by symmetric slip model and asymmetric slip model,combining with the geographical conditions and geological structure of the east Kunlun fault zone by using dislocation model;through program design with C language,the relevant parameters of the fault in GMT and geological and geophysical data of the area,carry on the forward solution and simulation of the east Kunlun fault zone.Handling the computational results with GMT software, we get the horizontal and vertical deformation of even dislocation and uneven dislocation of the area, which is a good result; analyzing the relationship between faulting and ground deformation by combining with geological and geophysical data;get some effective outcomes:1.The east Kunlun active fault zone has obvious rupture segmentation characteristics, there are differences in activity level of different sections. The vertical displacement components of the fault is smaller,and the whole fault zone is mainly left-lateral strike-slip fault.2.The fault zone has general structure feature that it is consisted like feather and the abrupt change of local strike.There are a few peak displacement along the fault zone trending. The asymmetric faulting brings about vertical deformation uplift or subsidence area in the steps of the dislocation.3.By computing the ground displacement on the fault planes with symmetric distribution model and asymmetric distribution model,we obtain that the differences of near-field deformation are largest in fault strike slip direction, smaller in direction normal to fault, and smallest in vertical direction.Viewpoints mentioned above is consistence with practical character. It is proved that dislocation theory model is feasible in study on relation between faulting and ground deformation.

  • 【网络出版投稿人】 长安大学
  • 【网络出版年期】2009年 08期
节点文献中: 

本文链接的文献网络图示:

本文的引文网络