Post-Construction Monitoring of Rehabilitated Highway Embankment Slope in Texas

Highway embankments built with expansive soils often undergo shallow slope failure due to permanent deterioration of soil's hydromechanical properties owing to its shrink-swell behavior. The alternate wetting and drying cycles result in the development of desiccation cracks, increase in water infiltration, and subsequent reduction in shear strength. This study provides an overview of the forensic analysis of the rehabilitation work performed on a failed highway embankment near North Texas. The rehabilitation of the embankment was performed by considering the detrimental effects of wet-dry cycles, and perched water table in the slope during rainfall events. The surficial layer was treated with lime and a subsurface drainage system was installed during the rehabilitation. A post-rehabilitation data-monitoring framework was developed and comprehensive analyses are presented to validate the effectiveness of treatment considering the temporal deformation and moisture content. Vertical deformation was monitored using Terrestrial LiDAR Scanners (TLS) and total station. Temporal deformation data showed marginal vertical deformation of embankment and the overlying pavement. Moisture sensor data illustrated minimal changes in volumetric water content of the treated layer, below the treated layer, and of the native soil. The deformation and moisture results align well with the expected performance and validate the efficacy of the surficial lime treatment with a drainage system for a long-term durable performance of the rehabilitated embankment.