Research On Mountain Pavement Structure Size Detection Based On 3D Laser Point Cloud

With the implementation of the National Highway Network Plan,it marks the beginning of the transition from the fast peak period of highway construction to the maintenance and repair-oriented management period,road detection is a necessary means to obtain engineering parameter data,evaluate engineering quality and determine maintenance or reconstruction plan.The traditional method of pavement structure dimension measurement is mainly manual measurement in the field,which exposes the problems of backward technology,low efficiency,and no guarantee of personal safety in the actual operation,in particular,the terrain is complex,steep terrain,vegetation blocked mountain road.At present,how to obtain the mountain road information quickly and accurately without disturbing the normal traffic is the problem that the road workers are concerned about.As a new surveying technology,the 3D laser scanning measurement can get the surface information of the target directly and quickly,and it has the characteristics of high precision,fast measuring speed and no contact,at the same time,the digital camera makes the point cloud have color,which provides more abundant data base for the point cloud data analysis and processing.The application of 3D laser scanning technology in road inspection can shorten the project cycle,improve the work efficiency and save manpower,and enhance the technical level and core competitiveness of road inspection.In this paper,a large amount of laser point cloud data obtained by vehicle-mounted 3D laser scanning system is used,the feasibility of using 3D laser point cloud data to measure the dimension of traditional pavement structure is verified by extracting important road parameters.Secondly,the model of solid pavement is constructed by reverse modeling,and the deviation is compared with the hypothesis model,break through the traditional idea of single point contrast detection,realize the whole detection of model,make it have practical significance in the whole control.In addition,BIM model is built based on parameters extracted from laser point cloud data,and the integration of 3D visualization and information is realized by Bim Technology and point cloud visualization.The research contents of this article are as follows:(1)In view of the present situation of the difficulty in manual detection of roads in mountainous areas,this paper introduces the methods and means of traditional road detection which are aimed at the width of road surface,cross slope and slope gradient,and compares them with the three-dimensional laser scanning technology,then the basic principle,system classification and measurement error of three-dimensional laser scanning are described in detail.(2)based on the abundant point cloud algorithm and processing software,the point cloud of road is processed by point cloud denoising,point cloud simplification,point cloud filtering,etc.,combining cloth simulation filtering with point cloud attributes(point cloud normal vector,point cloud curvature),the road point cloud classification and extraction of road point cloud are realized.(3)based on the laser point cloud data of the mountain road,the point cloud data of the road cross-section are extracted by the method of cross-section cutting,and the road width,cross-slope and slope gradient involved in the road detection are measured by means of virtual measurement,the feasibility of the application of 3D laser scanning technology to the measurement of pavement structure is verified by comparing the results of traditional manual measurement and completing the self-checking table.(4)Using Geomagic software to create a solid model of the classified road point cloud,and comparing it with the assumed road model,showing the size and position of the deviation in different colors,breaking through the traditional single point comparison in surveying and mapping,the whole control and visual detection of the model are realized.In addition,to meet the requirements of three-dimensional information,Bim Road Status Model was built based on point cloud data.