9 Step Scan to BIM Procedure – Airport Terminal Building
Architectural and construction Industry has evolved with use of technology. Engineers and architects have come from 2-dimensional manual drawings to 3-dimensional models to the latest laser-driven technology to create digital information known as asbuilt BIM model of the site under observation known as Scan to BIM Services. We can analyse the detailed Scan to BIM process by undertaking the case of renovating an airport terminal building. This busy airport terminal is workable and only needs a reparation for its terminal area, where passengers can stay during their transit hours.
The team involved in the refurbishing first undertakes the scan of the terminal building, which involves one or two personnel and a laser-driven scanner called lase scanner. Before the scan begins the parameters are inserted in the scanner to derive the actual data after scan.
Step by Step process of scanning the terminal building -
Initial setup of the scanner specific to the project site that is to be scanned.The 3D scanner used will capture a digital representation using the laser beams which rotate at high speed hitting different objects and materials of the terminal building undergoing the scan. After scanner hits this object the position relative to it is undertaken by the scanner which is termed as a point. For enabling more accuracy to the scanned data the team needs to collect a large number of points, which defines the resolution of the scan. The scan resolution generally varies depending on the various parameter such as the capacity of the scanner, density of point required to create 3D BIM model etc.Collection of such a large number of points is finally known as the point cloud data.Since entie building area needs to be scanned, multiple scans are to be taken from various locations.Under Scan to BIM services, the next step is to transfer this scan data of the terminal building to create the digital. Representations of it.
For proceeding ahead with our main work, this scanned data is transferred to the BIM ecosystem.
Scanned data is transferred to the system using any USB device or cloud for file transfer.BIM modellers convert the scanned data in the point cloud files using the software like Autodesk Recap, Faro Scene, Leica cyclone etc.This point cloud data is now worked upon in software like Revit, Archicad for the scan to Revit or scan to Archicad conversion for the next step.Once the registration process is done in Revit or Archicad, the data is analysed and the BIM Model is produced. The level of detailing or level of development ( LOD) depends on the objective of the scan to bim. The 3D BIM model can be prepared at LOD 100 to LOD 500.For producing this model the data is imported in a modelling software where the team of designers create the As-built BIM model content based on the construction and changes required in the terminal of Airport underuse.
The BIM models that are created using the above process can be of different levels like-
Level 0 - Since we procure the 3D laser data, Level 0 is not a part of the scan to bim process as only the 2D drawings are used.
Level 1 - Here the 3D CAD data is used for concept work, but the production information and any other documentation work remain in 2D.
Level 2- All the team members use a 3D CAD model but in their respective models. Thereby sharing of information is dependent on the different stakeholders which are involved in the project.
Level 3- The third level is a more collaborative approach under Building Information Modeling (BIM); which means every member or stakeholder will use the same model instead of their respective or separate 3D model.
Undertaking this step by step laser scanning of the Airport terminal by the Surveyor, we can conclude that ‘Scan to BIM services’ is a mechanism to undertake 3D Laser scanning of the site under consideration to bring about its digital representation. This digital BIM model is then used for evaluating, designing and overall assessment of the site. The basic advantage that we come across in this technique for renovating the Airport terminal is the real condition of the site at hand, thereby avoiding the errors which can come across during human inspection.
Some other general benefits of point cloud 3D modelling are-
The site to be visited only once to collect the 3D Data.
Accurate and proper theoretical data can be extracted.
Data collected in a short period.
Fast in sharing the information.
Saves time and money as errors are detected at initial stages.
Uncertainty of the data is reduced.
Usage of accurate and latest 3D data.
Direct feedback for the ongoing projects by the team involved.
Fast turnaround of Data and Deliverables.
Transparency, communication and collaboration is achieved
Overall construction cost is reduced for the project
Brings about faster decision making
Based on the above study we can conclude Scan to BIM can be effectively approached for recreating, renovating or construction of varied schools and colleges, Oil and Gas plants, Industrial areas and structures, High rise commercial and residential buildings, bridges and tunnels and Airport and Train stations.