用数字相关方法研究滑坡变形场  

A study of landslide deformation field with digital correlation method

作　　者：赵永红[1] 王航[1] 张琼[1] 谢雨晴 杨家英[1] ZHAO YongHong WANG Hang ZHANG Qiong XIE YuQing YANG JiaYing(Department of Geophysics, Peking University, Beijing 100871, China)

机构地区：[1]北京大学地球物理学系,北京100871

出　　处：《科学通报》2016年第28期3163-3171,共9页Chinese Science Bulletin

摘　　要：三峡大坝建成及动态蓄水运行后,滑坡成为库区地质灾害的主要形式之一.库区滑坡发育受大坝每年的蓄水泄洪周期及降水等因素影响.本文选择湖北秭归县卧沙溪滑坡作为研究对象,利用数码相机作为采集设备采集了2015年4月和5月的滑坡图像观测滑坡地表,用数字相关方法对滑坡图像进行处理得到滑坡位移场.位移量达到50 cm,但滑坡体表面各部分的位移量和方向不尽相同,滑坡运动是不均匀性的、非刚体运动.综合运用散斑法、灰度特征搜索等系列相关方法,成功处理了小形变关系、大位移量移动等滑坡特征问题,采用数码相机观测作为一种新的观测手段,还解决了采集图像的配准、灰度同级化等问题,并计算出滑坡体上各个点的方向和位移变化量,得到所有点的滑坡位移分布图,通过室内标定实验,误差在可接受范围内,验证了此方法的有效性.在满足滑坡监测要求的前提下,该方法操作简便、成本低、采集数据信息量大、可同时获取滑坡地表变形信息,有很好的推广前景.Landslides are one of the main geological disasters that persist in the reservoir after the completion and dynamic water storage of the Three Gorges Dam, and it is a threat to the safety of the residents along the river and shipping. The increase of landslides around the reservoir is affected by the yearly cycle of impoundment and flood water discharged from the dam, and precipitation, etc. Hence, monitoring the reservoir accurately and timely is one of the essential means for preventing disasters like landslide in the Three Gorges. In this work, we apply the photogrammetry method to the field of landslide monitoring on the basis of previous methods. We develop a solving method of landslide displacement field based on the image gray feature matching. First, image capture equipment like camera, vidicon is utilized to photograph the dynamic and static fields or movement process so as to obtain the time series images. Then kinematic variables like position, velocity, acceleration and deformation variables like displacement and strain are calculated by analyzing the images with digital correlation method. The essential idea of the image gray feature matching method is based on the viewpoint of statistics. Images in this method are treated as two-dimensional signals for searching corresponding match between signals by using correlation method. We can match two images around the same site before and after the landslide and obtain the displacement of this point. The Woshaxi landslide of Zigui County, Hubei Province is chosen as the study object, and we obtain the displacement field over time and the displacement vector of the landslide. The overall displacement is up to 50 cm, and the value and direction of regional displacement of the landslide surface are not completely the same. The overall landslide surface move rightward in the horizontal direction, and slid downward to the river in the direction vertical to the flow direction of the river. The vertical displacement is relatively larger in comparison with the horiz

关 键 词：三峡 卧沙溪滑坡 相关计算 位移场 图像灰度特征匹配 

分 类 号：P642.22[天文地球—工程地质学]