Application Of 3D Lidar In Highway Construction Quality Control

Pavement flatness and road structure layer thickness are the key indicators to evaluate the quality of road construction.The traditional detection methods have certain limitations for the detection and evaluation of construction sections.Ground 3D laser scanner has the advantages of non-contact,fast detection efficiency and high data accuracy,and its data can be used for surface flatness and structural layer thickness detection.Therefore,this paper focuses on the application of ground 3D laser scanner in pavement flatness detection and thickness detection of construction section,and carries out the following research work:(1)The technical principle of the 3D lidar scanning system is mainly expounded.The error propagation theorem is used to analyze its accuracy,which can meet the requirements of road construction evenness and thickness detection.(2)Combined with the characteristics of the point cloud data itself and the point cloud data of the road engineering analysis object,the key technologies in the processing of the road point cloud data are studied,including point cloud data denoising,point cloud data simplification,target fitting,road edge extraction and road triangular grid generation.(3)The evaluation methods and indicators of pavement evenness are summarized,and the reliability of ground 3D lidar scanning equipment for pavement roughness is studied.The results of repeatability test showed that the coefficient of variation was 4.442%,less than 5%,which met the requirements;The correlation test results show that the correlation coefficient between the test results and the level test results is~2=0.997≥0.98,which meets the requirements of correlation test.(4)The results are as follows:first,with the increase of the statistical interval,the calculated value of the index gradually tends to a stable value,which can better reflect the overall smoothness of the road section;Secondly,the index calculation results of elevation data of different lanes and different sections in the same lane fluctuate in different degrees.Therefore,the concept of lane weighted international roughness index is proposed to evaluate the smoothness of road sections.(5)A set of 3D laser radar scanning equipment is proposed to detect the flatness and thickness of construction section.There is a good linear relationship between the international roughness index and the proposed RS standard deviation index and the standard deviation of road roughness.(6)Combined with an example project,the thickness of the middle surface layer is detected,and each lane is divided into units according to the length of 5m.The index of pavement thickness deviation is put forward to evaluate the construction uniformity of the thickness of the structural layer,and the thickness compensation method for the thin part of the structural layer is put forward.