Amy Schutzbach Engineer of Physical Research Illinois Department of Transportation

PROJECT INFORMATION ID: R27-30 Project Cost: $199,246 Project Duration: 23 months Principal investigators – SIU - Edwardsville: Dianne K. Slattery, Ph.D., P.E. Kerry T. Slattery, Ph.D., P.E. 3-D Glasses not Included | The 3-D laser scanning set-up used by researchers in this study. The inset is a diagram of the 3-D scanner that shows the laser device’s degrees of movement potential.

PRIMARY GOAL: Use of laser scanner to evaluate pay quantities for earthwork operations Results: Time and manpower cost savings - 18 man-hours/mile (scan) vs. 28 man-hours/mile (conventional) Accurate to within.1 foot on rough terrain to distances of 600 feet Provides multiple ways of displaying data without additional field work – cross sections, skewed sections, intersecting roads Field techniques for collection and office work already within skill sets of survey personnel and resident engineers Need to develop standard practices for error analysis when using scanner

SECONDARY GOAL: Use laser scanner for real-time monitoring of settlement during pile driving operations Results: Values appear to be within error of laser scanning operation – movement of less than.1 foot cannot be measured with confidence Accurate to within +/-.1 foot, requiring additional surveying support to verify accurate measurements Variation likely due to slight movement of scanner during the operation

OTHER GOALS Successful: GIRDER DEFORMATION Accurate; measures movement >.01 foot in single scan Allows for less worker time in roadway and keeps surveyors out of roadway during scanning May be able to scan without any lane closure Scan can be completed in 15 min. Some Success: ARCHAEOLOGICAL INVESTIGATIONS Not feasible to determine characteristics outside of the scanner’s line of sight (eg., depth of excavation) Provides valuable 3D summary of location of visible features Inconclusive: PAVEMENT SMOOTHNESS GS type scanner inconclusive; vertical accuracy ≈.10 foot. GX type scanner may produce better results

OTHER GOALS Unsuccessful: RECONAISSANCE FOR DESIGN - MEASURING FOR PAYMENT BEFORE START OF CONSTRUCTION IN WOODED OR HIGHLY VEGETATIVE SURFACES Limited use/little utility – ground must be mowed, harvested or lightly cleared to ensure that accuracy is within.1 foot Unsuccessful: EVALUATING GRAVEL AND PAVEMENT THICKNESS – GS 200 was not adequate to calculate granular base or pavement thicknesses for quality control purposes – GX type scanner may produce better results due to dual axis compensation