As reagrds to new BIM Technology & Applications On-site ...1st up laser scanning in 3d...
South Perth-based McMullen Nolan and Partners Surveyors Pty Ltd is building its reputation in 3D laser scanning and imaging services for modelling of complex structures and plant sites.
Founded by John McMullen and Gerry Nolan, the company provides mapping and cartographic services, remote sensing and geographic information systems, topographic and detail surveys, and volumetric surveys.
McMullen Nolan was the first survey company in Australia to purchase a Cyrax 2500, a portable, 3D laser scanning system that captures, visualises and models convoluted items and structures such as petroleum production facilities, bridges and other civil works.
Unlike traditional surveying methods - which are labour intensive and thus carry related safety risks - there is no need to physically measure items and distances. The 3D laser scanning technology reduces the error factor from 10% to 2%, not a small consideration when you're operating offshore or in a remote area.
Complete surface geometry of exposed surfaces is captured in a matter of minutes in the form of dense, accurate 3D point clouds. These point clouds can be converted to 3D models, 2D drawings, contours, profiles or point to point measurements and can be used for a broad range of applications including those that require export to CAD and rendering software.
"It gives a far more complete as-built image [than traditional surveying]", stated Director Gerry Nolan. "Although scanning will not always give total 100% coverage, most of the time there is sufficient data to pick up the required detail. The registration or amalgamation of the scans allows the operator to conduct a complete 3D image detailing the different intensities of the scans".
"The system contains a housed digital camera allowing the operator to view the target area; however, we have discovered that the digital data - the photo - has become important. We are now using a technique where we utilise a high resolution digital camera to take a calibrated photo of the target area and then overlaying the photo on the scanned images. The result is a colour and image realistic 3D model."
So why would an engineer want a digital 'as-built' image of a production facility or industrial plant?
The comprehensive data set serves as a rich spatial reference for future developments and alterations while making sense of additions and alterations that have already been made to the existing design - highly relevant to future functionality and operability (and handy for historical and legal archives).
"Utilising a library of engineering templates we can model standard I and H beams or pipelines to the point cloud data, the software will then try to 'fit' the item into the existing structure", Nolan said. "It will give you an error analyses and advise what the variation is.
"If you have a drawing of an item, you can overlay it and check to see if it was built within tolerance. This is called 'conceptual design and interference checking', a vital part of the fabrication and construction inspection regime."
The benefit of using the laser scanning system is that it enables shorter project cycle times and does not interfere with ongoing construction or operational activities. Compared to traditional surveying techniques, this method offers improved quality results and faster. "Data acquisition is uninstructive and is viewed by the operator in real-time. This allows the operator to check that a complete scan was taken before moving onto the next setup", said Nolan.
McMullen Nolan has completed a number of surveys for major clients and projects over the years. They carried out a detailed, 3D laser scanning as-built survey of Phillips Petroleum's Bayu-Undan Wellhead Platform-1, during its final stages of construction in the Sambawang Marine and Offshore Engineering Yard in Singapore.
To avoid costly measurements offshore once the platform was installed, Phillips requested an as-built survey for future retrofits and maintenance of the platform. The scanned data was compared to the existing PDS design model to check supports, cable trays, equipment, safety access routes and the selection of critical pipe runs.
A total of 45 scans of the platform took the two-man team a mere four nights to complete. Phillips had requested that scanning be conducted at night so that the final stages of construction were not held up.
The Bayu-Undan maintenance division manager had welcomed the use of the technology, and wanted to get as much information as possible at an early stage so that all data were available when upgrades were required.
"Petroleum companies would benefit greatly down the track from conducting a visual of a whole platform before it goes offshore", stated Nolan. "It's like preventative maintenance. All that is then required is to scan new components and incorporate them into the existing model. This is carried out onshore so it can be confirmed there isn't any interference, rather than spending a whole lot of time and money sending surveyors offshore", he said.
Another major project was a design verification of BP Kwinana Refinery, ensuring there was no construction interference in a project area. McMullen Nolan conducted a 3D as-built survey of exiting pipe routes and tracks, allowing Worley Engineering to route a new 10 inch water pipe through a complex engineering structure.
The refinery was built in 1955 and has undergone numerous in-situ modifications without the associated as-built drawings. Reconstructing the existing structure in a CAD environment involved using the original 1955 design drawings and field measuring the additional features.
McMullen Nolan is currently completing 3D laser scanning activities at the Worsley Refinery in Collie, Western Australia, and has recently scanned the heritage listed East Perth Power Station.
The company also has links to Curtin University of Technology. This year saw the inaugural McMullen Nolan & Partners Surveyors Ptd Ltd Surveying Bursary presented to a third year Bachelor of Surveying student. The company is also a partner in the CRC for Spatial Information.
For more info. : http://www.pesa.com.au/publications/pesa_news/oct_04/pesanews_7213.html [1]
I have seen this new & exciting technology used on an existing building and it appears that it can be successfully used on existing 3d objects on existing structures. This will allow a great benefit in the 7D aspect of Building asset management.