Research On Tunnel Construction Monitoring Based On Laser Point Cloud

Three-dimensional laser scanning technology(in English: Three-dimensional laser scanning technology)has developed rapidly in the 21 st century.Laser scanning technology is widely used in various industries,such as reverse engineering,cultural relics protection,unmanned driving,and electric power inspection.It has the advantages of no contact measurement,high accuracy,high data collection efficiency,and the ability to collect complete coordinate and color information.In the field of engineering construction,3D laser scanning technology can be used for construction monitoring of subway tunnels and buildings.It overcomes the shortcomings of traditional monitoring methods such as contact measurement,low degree of automation,less monitoring points,and higher requirements for equipment placement and improves the efficiency of construction monitoring.In recent years,3D laser scanning technology has made great breakthroughs in point cloud data processing.The processing methods of 3D point cloud are more diversified,and the data processing efficiency has also been greatly improved.This paper uses 3D laser scanning technology to solve the monitoring problems in the construction of subway tunnels,and monitors the installation accuracy and displacement of the segments during the construction process.Compared with the method of using traditional total stations and other instruments for construction monitoring,3D laser scanning technology can quickly collect the overall point cloud information of subway tunnels,including 3D space coordinate information,color information,etc.and then use Visual Studio 2015 and PCL point cloud library processes the collected point cloud data,and use Cloud Compare and Geomagic Studio for data preprocessing and modeling.In contrast,the traditional method can only use a few single points to estimate the deformation of the subway tunnel,and it can not carry out the later modeling.This article briefly describes the working principle of the 3D laser scanner.Preprocessing the scanned point cloud includes point cloud denoising,point cloud reduction,and finally the tunnel section interception and fitting,and point cloud 3D reconstruction.In the experimental process,aiming at the problem of overall deformation of the tunnel,the tunnel section fitting is proposed to monitor and analyze the whole tunnel,and the local point cloud extraction fitting based on Angle is proposed to monitor and analyze the tunnel radiusfor the problem of local deformation of the tunnel.The traditional total station measurement is compared with the 3d laser measurement.Finally,the results show that the measurement precision of 3d laser scanning technology basically meets the monitoring requirements in the construction process.Therefore,the construction monitoring method based on 3d laser scanning technology is feasible and has more advantages...