Application Of 3D Laser Scanning In Slope Support Structure Monitoring

The three-dimensional laser scanning technology is developing at an exceptionally rapid rate.Its appearance overcomes the shortcomings and deficiencies of traditional measurement methods and has been gradually applied to related fields such as cultural relic protection,forestry,digital city,topographic mapping,deformation monitoring,and 3D reconstruction and many more.Compared with the traditional measurement methods,the advantages of three-dimensional laser scanning technology also make it have a wide application prospects in the safety monitoring of slope engineering,but also there are a lot of problems.The use of three-dimensional laser scanners for efficient slope monitoring methods,monitoring accuracy,the selection of deformation extraction methods,etc.,have yet to be further studied.Taking a certain slope in Lanzhou City as an example,the paper conducts research on the related issues of the three-dimensional laser scanning technology in the safety monitoring of the slope.The main work is as follows:(1)Based on the collection of existing achievements,the working principle of the 3D laser scanner and the working performance of the Z+F5010C 3D laser scanner are introduced.The point cloud data processing methods and cloud errors of 3D laser scanning technology in slope monitoring are summarized.(2)A slope deformation monitoring and controlling network is established,and monitoring points are placed on the surface of supporting structures,and are monitored by total station.It is proposed to bury the screw on the slope surface to fix the target ball for the slope monitoring and realizing the coordinate transformation.By the means of experiment,the best scanning resolution suitable for monitoring in this slope is preliminarily determined by four indicators,that is,the number of points on the target ball,the fitting accuracy of the center of the target ball,the size of the scanning data,and the scanning time.(3)The calculation formulas of plane error and elevation error of the 3D laser scanner deformation monitoring are deduced.The factors that influence the error in the plane point and the error in the elevation are theoretically analyzed,and the influencing factors are taken.(4)The accuracy analysis experiment of the 3D laser scanner in actual slope monitoring is designed.The experimental data are acquired through the target ball and the target paper.Then the data are analyzed in detail,and the scanning resolution and scanning distance are analyzed.The distance accuracy and scanning point accuracy are verified,and the accuracy level that the Z+F5010C 3D laser scanner can achieve in actual monitoring is obtained.(5)The pre-processing of de-noising,point cloud splicing,coordinate conversion,and point cloud registration were performed on the collected 12 periods cloud data;through the splicing experiment with different number of target spheres,the number of target spheres on the mosaic accuracy is obtained.Then the pre-processed point cloud data at each stage of the deformation are analyzed by the methods of point analysis,line analysis and surface analysis,and are compared with the total station monitoring data,which proved the 3D laser scanner can be used to monitor the deformation of the slope.The effectiveness and reliability can provide reference for safety monitoring of related slope projects.