大同盆地现今地壳运动特征分析

发布时间：2018-04-20 18:33

本文选题：大同盆地 + GPS速度场　；参考：《长安大学》2015年硕士论文

【摘要】：大同盆地是汾渭盆地内地壳构造活动剧烈,地质灾害多发的地区,尤其近年来大同市发育的地裂缝成为了最为典型和严重的灾害,给当地建筑的安全带来了威胁。为了进一步了解大同盆地的地壳形变运动特性以及与地质灾害的关系,本文基于GPS获取的大同盆地实测速度场资料,进行了以下的学习研究:采用多面函数法建立了该区域的水平和垂直速度场模型,并根据已建立的水平运动模型,通过对该模型求偏导数的方式求解了大同盆地的应变参数,得到了区域的应变场。从得到的应变面膨胀图和剪切应变图中看出大同盆地应变显著区域位于大同市区,并且大同市的地裂缝都经过了这些应变的高值区域。因此在这些拉张与剪切力的作用下,同时结合超采地下水等其它导致地面沉降的因素,最终发展出了地裂缝灾害。接着通过实测和拟合得到的速度场资料,使用Def Node负位错反演程序,初步计算得到了大同盆地口泉断裂中段的闭锁程度,反演得到的结果表明口泉断裂中段的闭锁程度整体上约为0.4,闭锁程度不大,断层的蠕滑要多于粘滑,整体上处于蠕滑状态。因此作为一条活动断裂,应考虑由于其错动所造成的对建筑物的缓慢破坏作用并对其加以防范。
[Abstract]:Datong basin is an area with intense crustal structure activity and frequent geological hazards in Fenwei basin. In recent years, the ground fissures developed in Datong City have become the most typical and serious disaster, which threaten the safety of local buildings. In order to further understand the characteristics of crustal deformation and movement in Datong Basin and its relationship with geological disasters, this paper is based on the measured velocity field data of Datong Basin obtained by GPS. The following studies are carried out: the horizontal and vertical velocity field models of the region are established by using the multi-plane function method, and the strain parameters of the Datong basin are solved by calculating the partial derivative of the model according to the established horizontal motion model. The strain field of the region is obtained. From the strain plane expansion diagram and shear strain diagram, it can be seen that the significant strain area of Datong basin is located in Datong urban area, and the ground fractures in Datong City have passed through the high value region of these strains. Therefore, under the action of these tensioning and shearing forces, combined with other factors that lead to ground subsidence, such as over-exploited groundwater, the ground fissure disaster was finally developed. Then, by using the Def Node negative dislocation inversion program, the locking degree of the middle section of the Kou Quan fault in Datong Basin is preliminarily calculated by using the velocity field data obtained from the measured and fitted data. The inversion results show that the degree of locking in the middle section of the Kou Quan fault is about 0.4 on the whole, and the degree of locking is not large, the creep of the fault is more than that of the viscous slip, and the whole is in the state of creeping. Therefore, as an active fracture, the slow damage to buildings caused by its dislocation should be considered and prevented.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P227

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