G318林芝—波密段斜坡地震动力响应及失稳机理

发布时间：2018-01-29 06:14

本文关键词： 斜坡地震动力响应地层结构数值模拟　出处：《西南交通大学学报》2017年03期 　论文类型：期刊论文

【摘要】：斜坡地层结构及地震动力响应是斜坡失稳破坏的重要因素.为进一步研究斜坡地震动力响应的差异性及地震动力响应规律,以G318林芝—波密段典型斜坡中的四类地层结构斜坡为原型,利用FLAC3D建立斜坡数值分析模型,通过在坡面及坡体设置监测点,输入Kobe地震波,对监测点的应变、水平位移及加速度等动力响应进行分析研究.结果表明:土层-岩层斜坡的坡面PGA(peak ground acceleration,PGA)放大系数随高度增加而增大,且在一定高度存在极值;坡体PGA放大系数与坡高呈线性增加,且千枚岩斜坡PGA放大系数更大,最大可达10.7;岩土接触带两侧,土层与岩层的水平位移差异明显,两者至少相差一个数量级,导致岩土接触带两侧介质变形不协调,这是土层-岩层斜坡在岩土接触带发生滑动的主要原因;不同土层斜坡的水平位移及PGA放大系数也有很大不同,且土层-岩层地层结构斜坡的失稳破坏程度主要受土层类型的控制.
[Abstract]:Slope formation structure and seismic dynamic response are important factors of slope failure. In order to further study the difference of slope seismic dynamic response and seismic dynamic response law. Taking four types of stratigraphic structural slopes in the typical slope of Linzhi Bomi section G318 as the prototype, the slope numerical analysis model is established by using FLAC3D, and monitoring points are set up on the slope surface and slope body. Input Kobe seismic wave, strain to monitoring point. The dynamic responses such as horizontal displacement and acceleration are analyzed and studied. The results show that the slope of soil-rock slope is PGA(peak ground acceleration. The magnification coefficient of PGA increases with the increase of height, and there is an extreme value at a certain height. The PGA magnification factor of slope body increases linearly with the height of slope, and the PGA magnification factor of phyllite slope is larger, the maximum is 10.7; On both sides of the contact zone, the horizontal displacement of soil layer and rock layer is obviously different, and the difference between them is at least one order of magnitude, which leads to the medium deformation on both sides of the contact zone is not coordinated. This is the main reason for the slip of the soil-soil slope in the geotechnical contact zone. The horizontal displacement and PGA magnification factor of different soil slopes are also very different, and the degree of instability of the slope is mainly controlled by the type of soil layer.
【作者单位】：西南交通大学土木工程学院;西藏大学工学院;西南交通大学地球科学与环境工程学院;广西交通规划勘察设计研究院有限公司;
【基金】：国家自然科学基金资助项目(41462012) 陕西省引汉济渭工程科技资助项目(YHJW-KY-007)
【分类号】：P315.9;U416.1
【正文快照】： 国道G318林芝—波密段位于藏东南地区,平均海拔达3 500 m,位于雅鲁藏布江中下游,构造活动强烈,地形复杂,属高山峡谷地貌,是西藏的主要牧业区.由于特殊的地质地理环境,研究区地质灾害频发且形式多样,以崩塌、滑坡、泥石流为主[1].受当地气候环境影响,岩石风化作用较为强烈,部分

【相似文献】