The Structural Information And Deformation Monitoring Of Rock Slope Based On 3D Laser Scanning Technology

The stability of the rock slope is mainly controlled by a large number of development discontinuity within the slope,therefore,it is of great significance to obtain the information of rock mass discontinuity accurately,efficiently and comprehensively for the analysis of the stability of the slope.In addition,the deformation monitoring of the slope is also one of the main methods to predictive the stability of the slope.Through the analysis of the deformation data of the slope;it can provide the important basis for slope stability prediction.As a new method of surveying and mapping,three dimensional laser scanning technology has attracted people's attention as soon as it comes out.It can realize the rapid scanning of long distance,high precision and high efficiency.By launching laser point to the object,it can obtain the real 3D information of the object surface.Three dimensional laser scanning technology can quickly acquire the point cloud data on the slope surface,and then extract the discontinuity information and monitor the deformation of the slope.This paper combines Geomatics and Geotechnical Engineering,a thorough study of the automatic extraction of rock mass structural information and the monitoring of the deformation of the slope based on the 3D laser scanning technology is carried out.The following research results are mainly obtained:(1)The development of 3D laser scanning technology is summarized,and its technical principles and technical characteristics are introduced in detail.The main methods of the extraction of the discontinuity information collection and slope deformation monitoring are summarized,and the advantages of three-dimensional laser scanning method are analyzed.(2)A detailed introduction to the data acquisition and processing flow of 3D laser scanning technology,including how to select the location of the scanner,how to set the scanning point spacing according to the engineering requirements,the method of getting point cloud coloring information,and the principle of coordinate conversion.(3)The automatic method to extract rock mass discontinuity based on 3D point cloud data is proposed.Based on the improved Ransac algorithm,the plug-in RSD(Ransac Shape Detection)of CloudCompare is developed,and is adapted to a new plug-in RDD(Ransac Discontinuity Detection)that can be applied to the extraction of rock mass discontinuity.The real boundary of the discontinuity is depicted by Concave algorithm,and the real area of the discontinuity is calculated.(4)The automatic method to extract blocks based on 3D point cloud data is proposed.Based on the extraction results of the discontinuity,we developed a new program,which is used to analyze the intersecting information of the discontinuity and create the candidate blocks,and then uses the Floodfill algorithm and Volume method to identify the real block and virtual block,and finally calculate the block size of the block.(5)The slope deformation monitoring based on 3D point cloud data is studied in this paper.By extracting the typical blocks of the slope,a deformation monitoring method based on the typical block is proposed,which can monitor the deformation of 10mm or less with high accuracy,and also the area change of the discontinuity which are used to create the block.At the same time,it can also monitor the complex deformation of the block,such as the rotational deformation.