The Move From BIM to TIM
In the last few years, BIM has become a successful and proven project delivery system in the vertical construction industry. As owners seek to standardize the BIM model, a shift to improved methods is being pushed by the General Services Administration and other large global corporations. “The learning curve is behind us in understanding point cloud data,” says Michael Frecks, president and CEO of Omaha, Neb.-based Terrametrix LLC, a firm that provides terrestrial mobile LiDAR scanning (TMLS) services and has been involved in laser scanning since 2000. “The combined use of static and mobile LiDAR techniques can be a big benefit in certain environments, especially with the fast-developing indoor mobile applications. These two different techniques complement one another and can significantly reduce field data acquisition time.”
Managing a project through its lifecycle requires a succession of strategies that can only be successfully implemented with accurate information and documentation. Piloting activities within services requires addressing the needs of trade consultants, architects, lawyers, auditors and insurance companies through communication, visualization and software applications. Being able to identify the activity of a project in real time through the use of 3D/4D laser documentation and scanning enhances performance-based engineering, computational mechanics, design construction integration, reliability and risk analysis for hazard mitigation, LEED issues, and engineering informatics.
As views of measurement become more sophisticated, as national and international calibration bodies struggle toward organization, and as the regulation of quality assurance assumes a more prominent role in domestic and international trade, there is increasing interest in the objective validity of measurements at all levels. BIM provides this validation and helps to mitigate risk through proactive management. “There are many benefits to be realized as our industry moves from the 2D world to not just the 3D world, but the BIM world,” says John Russo, founder of the U.S. Institute of Building Documentation (USIBD) as well as president and CEO of Architectural Resource Consultants (ARC), one of six firms selected by the General Services Administration to receive a five-year, $30 million Indefinite Delivery, Indefinite Quantity (IDIQ) contract for nationwide laser scanning services. “Smart, intelligent, data in the form of a BIM is providing new dimensions for safety, data integrity and training.”
Instrumentation includes static and mobile 3D laser scanners, calibrated total stations, and electronic levels. Laser scanning and related nondestructive measurement technologies have proven to be cheaper, better and faster than traditional surveying and other measurement techniques. In many circumstances, because laser scanners produce extremely robust data that is virtually a complete record, they are more accurate with measurements to very small units. 3D laser scanning can provide an unobtrusive, noncontact data capture method in dangerous or difficult-to-access environments. It collects geometry that could not otherwise be obtained by architects and is a foundation for BIM models.
However, more important than the instrumentation is the experience of the surveyors and technicians with this type of work and their understanding of precision measurement within a 3D environment. All construction system monitoring or measurements of elements of interest must have an accuracy of +/-¼ inch to a level of certainty of one standard deviation. In some cases, greater accuracies, precision or levels of detail are required on certain areas of interest.
Environmental concerns and rising energy costs will continue to drive the building industry toward sustainable design. BIM, supported by appropriate software like Revit, Archicad, Bentley Architecture, and Vectorworks, has the information power to reduce the cost of sustainable design, allowing analysis and certification throughout the lifecycle of the project.
As firms begin to understand the capabilities of BIM to support every stage of the project life cycle—from inception through start-up and operations to decommissioning and closure—they are sparking a new movement that is spreading the value of BIM to an even broader range of clients. “The profession has modified the term to transportation information model (TIM),” says Kourosh Langari, senior transportation engineer with URS, a worldwide engineering, construction and technical services organization. “The TIM concept uses the geographic information system (GIS) as the cadastral fabric for wide area viewing and cartography. As one gets closer to the reference line of the transportation corridor, technologies like terrestrial mobile LiDAR scanning will fill in the gap for subcentimeter accuracy.”
Note: This article is a shortened version of an article that will appear in the August issue of POB. Want to learn more about the move from BIM to TIM? Kourosh Langari and Michael Frecks will address this topic in their presentation, “Using LiDAR in GIS,” at the Survey Summit in San Diego on Sunday, July 22, 2012, 10:30 a.m.-12:00 p.m. in the Ford A-Marriott Marquis and Marina room.
Image: A transportation information model (TIM), which combines BIM with GIS and technologies such as terrestrial mobile LiDAR scanning (TMLS). Image courtesy of URS.