Sichuan Surveying and Mapping Instrument Company introduces the project background to you:

　　Wenzhou Longgang Bridge is located on the Aojiang River in Wenzhou City,Zhejiang Province.Aojiang River is one of the eight major water systems in Zhejiang,belonging to Pingyang County and Cangnan County in Wenzhou City.The bridge has been basically completed,and the scaffolding has not yet been removed.The pavement on one side of the bridge has been completed,and the cement pavement is being paved on the other side.At the invitation of the construction unit,we have scanned the entire steel structure bridge,collected 3D point cloud data,and exchanged technical solutions for 3D inspection and 3D on-site assembly.

　　Technical advantages

　　Steel structure bridges are usually hoisted by ships during hoisting,while ships move in the water with seawater flowing backwards.Therefore,it is very complex to use traditional total stations and prisms for on-site construction guidance.According to the actual situation of on-site hoisting,hoisting a chord takes a whole day.

　　Using a three-dimensional laser scanner to guide on-site construction can significantly reduce on-site construction errors.Rapid,efficient,and omnidirectional scanning coupled with rapid deviation analysis guidance from post-processing software can make up for the shortcomings of the traditional scheme of total station with prism.The high-precision features of phase scanners,combined with the advantages of contactless and efficient point data acquisition and powerful data processing software,ensure the reliability and practicality of data analysis results.

　　Solution

　　1.3D laser scanner point cloud data acquisition;

　　In this project,we used the 5010C in the IMAGER series from German Z+F company,as shown in the right figure,with a scanning angle of 320°×360°,scanning rate of 1016000 points/second,Z high resolution of 0.1mm,accuracy of 0.2mm(80%reflectivity at 10m).

　　2.Performing data preprocessing in the laser control;As shown in Figure 4,the point cloud data of Longgang Bridge is preprocessed in the laser control.

　　3.Performing data post processing in geo matic qualification;As shown in Figure 5,data post processing is performed on the original point cloud model,removing scaffolding,and forming relatively clean original point cloud data;Figure 6 shows the original design model obtained from the design unit,which can be directly imported into geomatic software after conversion;Figure 7 shows the effect of 3D comparison and analysis between the design model and the measured steel structure bridge,and using chromatography to display it.

　　4.Data deviation distribution results report output.