8/3/2010
Laser scanning technology, which was recently validated by the Illinois Center for Transportation (ICT), has the potential to increase efficiency and control costs for Illinois highway and bridge construction activities. The technology produces three-dimensional representations of objects and surfaces with a collection of data points, or "point clouds," accurate to within a few millimeters (0.01 feet).
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Laser scanning technology, which was recently validated by the Illinois Center for Transportation (ICT), has the potential to increase efficiency and control costs for Illinois highway and bridge construction activities. The technology produces three-dimensional representations of objects and surfaces with a collection of data points, or "point clouds," accurate to within a few millimeters (0.01 feet).
Taking measurements in this manner could increase field productivity and improve the integration of design and construction survey data.
However, to prove the accuracy of this new method, data obtained using laser scanning technology needed to be compared to data obtained using traditional methods. ICT recently completed this necessary validation and provided the positive results to the Illinois Department of Transportation (IDOT).
As part of the research, ICT investigators Dianne and Kerry Slattery performed laser scans on several construction projects in IDOT District 8 and used the data analyzed to verify the comparability of laser scan results with currently specified construction measurement and quantity determination methodology. The investigators examined ways to integrate design drawings and geospatial project data with construction measurements and developed recommended procedures for implementing the technology for specific construction applications.
The investigators also evaluated the use of the laser scanner for real-time monitoring of settlement of adjacent structures during pile driving operations. For these evaluations, the scanner was set up near a job site, and scans were taken periodically to plot changes in ground elevation and movement of structures.
Additionally, Kerry Slattery developed software that provides a user-friendly graphical interface for viewing, manipulating, and using scanner data. The results of this research validated laser scanning technology for several applications in highway construction, including measuring earthwork quantities, surveying ground or structure displacement or damage, and monitoring widespread ground movement due to pile driving, excavation, or other causes.
Although the equipment cost remains high compared to the electronic total stations currently used to measure earthwork quantities, the benefits could easily outweigh these costs.
"Over the course of the research project we observed that market forces are driving costs down so, like all maturing technology, capabilities are continuing to improve while costs become more competitive," explained Dianne Slattery.
This method of laser scanning validated by ICT has already been used for historical purposes. The Illinois Transportation Archaeological Research Program used the technology to provide a survey for an archaeological dig on IDOT's Mississippi River Bridge Project. The $640 million Mississippi River Bridge project will result in the first bridge built connecting downtown St. Louis and southwestern Illinois in more than 40 years.
IDOT personnel are beginning to assess and plan for the implementation of the laser scanning technology on construction projects for Illinois highways and bridges by using the information contained in the final report along with the developed software. Ted Nemsky, the technical review panel chairman for the research project, says, "I believe that the research from this project helped us at IDOT gain confidence in the use of laser scanning technology so that it may be implemented as another tool for performing the labor intensive task of generating earthwork models to calculate pay quantities, which with the current methods are very time consuming to generate. This research has shown that laser scanning technology can effectively be used to reduce the number of man hours required by more traditional survey methods." The technology has great potential to increase efficiency and control costs for IDOT.
The Illinois Center for Transportation is a premier transportation research center that builds on the experience of renowned experts in transportation and related fields at the University of Illinois, the Illinois Department of Transportation (IDOT), and other universities in Illinois and across the country by providing the appropriate tools and support required for objective research.
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Contact: Leslie Sweet Myrick, Illinois Center for Transportation, 217/892/5018 x225.
If you have any questions about the College of Engineering, or other story ideas, contact Rick Kubetz, Engineering Communications Office, 217/244-7716, editor.