Three-dimensional Laser Scanning Deformation Monitoring And Stability Analysis Of High Steep Loess Slope

Due to its vast territory,unique geographical environment and complicated geological conditions,geological disasters such as landslides,debris flow and slope instability often occur in china.Especially in the northwest region,the loess is widely distributed,because of the collapsibility of loess,it is easy to cause settlement when there are contacted with water,which leads to slope instability and overturn,and threatens the adjacent buildings.Therefore,it is urgent to evaluate the current situation of the slope and predict the trend of the slope deformation through the deformation monitoring of the slope.Advanced monitoring techniques can provide powerful guarantee for slope monitoring,3D laser scanning technology,which is a new way of deformation monitoring in recent years,It can transform the traditional single point deformation observation mode,and can quickly and efficiently conduct the overall monitoring and analysis of the slope.This method can make up the deficiencies of traditional monitoring technology in a certain extent.In this paper,based on the application of three-dimensional laser scanning system in the high steep loess slope in northwestern China,the issues r elated to the deformation monitoring of the slope are discussed in terms of overall analysis and feature analysis.In the aspect of whole analysis,3D laser scanning technology has the characteristics of rapidly collecting a la rge number of point cloud data,the slope is scanned and its point cloud data is collected in stages,after the point cloud data preprocessing and splicing,three-dimensional models of slopes in each period was established,the deformation value was obtained by differential comparison method,and the specific application flow of the STONEX X300 three-dimensional laser scanning system on the slope was introduced,finally obtained the deformation trend of the slope;In the aspect of feature analysis,the anchor end of the surface of the slope is a deformation monitoring block,from the point cloud data,the coordinates of the center point of the deformation monitoring block in each period were extracted as the research object,a grey prediction model GM(1,1)was established to perform a fitting prediction analysis,due to the large number of external disturbance factors in the process of collecting data of slope three-dimensional point cloud,kalman filtering was used to filter the original time series.Through the comparison and analysis of engineering examples,it can be obtained:(1)By comparing and analyzing the three dimensional models of the first to the second and the second to third phases,it is found that the deformation of the slope tends to be stable step by step,and the main reason is the influence of seasonal change and the stability of the new slope.(2).Three dimensional laser scanning technology can monitor the high and steep loess slope better in Northwest China,and get the trend of deformation and development quickly and effectively,so as to provide convenience for the prevention and treatment of high and steep slope disasters in the future.(3)Kalman filtering can filter and denoise the time sequence of point cloud data deformation monitoring points well,which is of great significance for improving the prediction accuracy of the gray model of three-dimensional laser scanning deformation monitoring points.