3.1 Technology application of BIM
The UAV(Unmanned Aerial Vehicle)is used for surveying and mapping at various stages of the construction,and the actual scenes in the scene are left in three dimensions to reveal the entire construction process.During the process of modeling,single-professional threedimensional calibration and multiprofessional coordination are carried on to achieve efficient professional integration and coordination,reduce conflicts between various professions and design changes,reduce the changes caused by functional layouts and architectural space collisions that cannot be found in 2D drawings.Detailed design and construction of complex nodes were also carried on at the beginning of the project.With the 3D BIM disclosure,the information of each participant in each stage is shared and symmetric,which avoided the change or rework caused by poor information communication[1].The 3D site layout ensured the reasonable division of machinery and materials during the construction process.Then simulate the difficult schemes,optimize and visualizes the scheme.With the whole process of virtual construction,the entire construction state can be adjusted,which ensured the rationality of the schedule.With the project quantity acquired from the BIM model,the cost management efficiency improved[2].
Figure 2 Results of tilt photography of the project
Figure 3 Intersection model of the project
The application points include tilt photography(Figure 2),model establishing(Figure 3), 3D review, construction deepening,site layout,visualization disclosure,project simulation(Figure 4),virtual construction(Figure 5),engineering lifting,etc.Partial results are as follows.
Figure 4 Project simulation of E4 and N6 of the project
Figure 5 Utility tunnel virtual construction of the project