地震作用下边坡岩体松动深度的研究

发布时间：2018-08-20 09:08

【摘要】：地震灾害是世界上很多国家所面临的严重地质灾害之一，对于我国来说也同样如此，2008年的汶川发生的8.0级地震给当地居民造成了巨大的人身伤亡和财产损失。在地震发生后，交通的抢通保通，无论是对于地震发生初期的抢险救人，，还是对于震后灾区的恢复重建，都是至关重要的[1]。通过对地震灾区的交通情况现场踏勘后发现，地震导致的坡表松动岩层，在震后地下水等外部因素的作用下，极易沿该深度发生再次破坏，严重影响交通的安全。因此，如何简便、有效的确定震后边坡的岩体松动深度，为震后公路工程设施的安全程度进行检测评估与修复加固等工作奠定坚实的基础，成为震后公路恢复重建阶段所面临的重要课题。遗憾的是通过查阅中外文献后，尚未发现有关于地震作用下边坡岩体松动方面的研究。为此，本论文从理论和工程实际出发，着重探讨以下主要内容： 1）在汶川地震灾区，通过对工程地质条件的现场勘查，以及对边坡的失稳特征和变形特征进行分析后得知，边坡的几何特征、地形地貌和岩体性质与边坡的地震反应有着密切的关系[2]。 2）查阅文献发现，在地震作用下对边坡的松动深度的研究，可借助于黄润秋等人的卸荷带理论。在动力有限元理论的基础上运用FLAC软件对边坡在地震作用下进行数值模拟分析，研究主要针对地形地貌、坡体材料和动荷载条件三个方面，通过逐一改变边坡的坡度、坡高、材料性质以及地震动的荷载频率和振幅等条件来探讨边坡的塑性区和受拉区的分布情况，以此来判定边坡的地震松动深度。 3）采用面波技术探测边坡地震松动区。由于现有规范进行岩土划分时根据岩土的横波波速（横波速度与岩土的物性参数密切相关），因此从面波相速度与深度的彩色剖面图很容易得到测试断面的岩土层的总体分布情况。在通过和超声波测试、现场钻孔资料的比对后，采用面波法确定边坡的地震松动深度，建立松动深度的物性指标相关关系，提出一套简便的检测方法。
[Abstract]:Earthquake disaster is one of the serious geological disasters faced by many countries in the world, and the same is true for our country. The 8.0 earthquake occurred in Wenchuan in 2008 caused huge casualties and property losses to local residents. After the earthquake, it is very important for the transportation to rescue the people in the early stage of the earthquake and to restore and rebuild the disaster area after the earthquake [1]. It is found that the loose rock layer of slope surface caused by earthquake is easy to be destroyed again along this depth by external factors such as underground water after the earthquake, which seriously affects the safety of traffic. Therefore, how to determine the rock mass loosening depth of the post-earthquake slope is simple and effective, so as to lay a solid foundation for the inspection, evaluation, repair and reinforcement of the safety degree of the post-earthquake highway engineering facilities. It has become an important task in the stage of road reconstruction after earthquake. Unfortunately, after consulting Chinese and foreign literature, there has not been any research on slope rock mass loosening under earthquake action. Therefore, this paper focuses on the following main contents from theory and engineering practice: 1) in Wenchuan earthquake disaster area, through the field survey of engineering geological conditions, After analyzing the instability and deformation characteristics of the slope, it is found that the geometric characteristics, topographic features and rock mass properties of the slope are closely related to the seismic response of the slope [2]. The study on the loosening depth of slope under seismic action can be done by means of the unloading zone theory of Huang Runqiu et al. On the basis of the dynamic finite element theory, the numerical simulation analysis of slope under earthquake action is carried out by using FLAC software. The research mainly aims at the three aspects of terrain and geomorphology, slope material and dynamic load condition, by changing slope gradient and slope height one by one. The distribution of the plastic zone and the tensile zone of the slope is discussed under the conditions of material properties, loading frequency and amplitude of the ground motion. 3) the seismic loosening zone of the slope is detected by the surface wave technique. According to the shear wave velocity of the rock and soil, which is closely related to the physical parameters of the rock and soil, it is easy to obtain the rock and soil layers of the test section from the color profile of the velocity and depth of the surface wave phase. The overall distribution of After comparing with ultrasonic test and field drilling data, the surface wave method is used to determine the seismic loosening depth of slope, and the correlation relation of physical property index of loosening depth is established, and a set of simple detection method is put forward.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P315.9;U416.14

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