Use of Relative Surface Technology for Creation of Relative Milling Surface Models and During the Automated Machine Guidance Milling Operation

Status: Complete
Report Date: 06/02/2021

Summary:

The Minnesota Department of Transportation needed to correct the existing profiles of the eastbound and westbound lanes of TH2. This roadway was reconstructed 9 years ago, and since then, it has experienced significant pavement movement due to the presence of silt seams in the subgrade material. The movement of the roadway had stabilized and was still considered to be in good structural condition. Consequently, it was decided to move forward with correcting the profile to remove the significant irregularities that were present within the roadway profile. After evaluation of the project constraints, it was decided that the most cost-effective solution was to use a relative system (with respect to the existing surface) for creation of the existing surface and milling-depth models, in lieu of conventional survey and milling methods that later require use of robotic total stations during the milling operation. The project team selected the Topcon SmoothRide Resurfacing solution for both creation of the 3D model and use during the milling operation. The accuracy of the relative surface LiDAR scan was within 3 to 5 mm in the vertical direction and only required approximately 8 hours to collect, clean and review the relative surface measurements, while conventional methods would had required several days, or more. It was found that the relative surface measurements adequately identified and documented the magnitude of the vertical roadway movement and could be used to assist with the correction of irregular profiles of roadways. Consequently, the Topcon SmoothRide Resurfacing solution was also used during the milling operation and was considered successful.

Final Deliverables:

Report #2021-09