As-Built Verification, Condition Assessment, and Forensic Analysis of Mechanically-Stabilized Earth Walls Incorporating Terrestrial Lidar

Terrestrial Lidar scanning has the potential to be a powerful tool for condition assessment, as-built verification, and forensic investigation of MSE and GRS structures. This paper presents a method to extract vertical profiles of wall facing position from a lidar data set. For profiles obtained at one time, the profiles can be compared to each other to check the vertical and horizontal wall alignment or they can be compared to the construction drawings and specifications. Profiles of the same location obtained at different times can be compared to extract the settlement and lateral displacement of the wall facing. A series of laboratory tests are described that were used to conclude that the texture and reflectivity of split-block facing does not interfere with the ability of the lidar to achieve the measurement accuracy specified by the manufacturer. The proposed data processing work flow is demonstrated using two full-scale walls.