Nebraska LTAP


Date of this Version


Document Type



NDOT Research Report SPR-P1(20), 2003

Nebraska Department of Transportation, Lincoln, Nebraska, United States


Highway shoulder rocks are exposed to continuous erosion force due to unexpected floodings caused by climate change. The evaluation methods of the erosion resistance of highway shoulder rocks are not currently well-developed. This study developed a new large-scale testing device, the University of Nebraska-Lincoln Erosion Testing Bed (UNLETB), which has the capability of testing the shoulder gravels. Different gradations were tested using UNLETB, and the results distinguished a high-resistant group and a low-resistant group. The low resistant group was treated with different binding agents: Ammonium Lignosulfonate (LIGNO10), Soybean Soap Stock, and DirtGlue. The treated samples showed better erosion resistance based on the binding agent and the sample type. Then, a hydrodynamics-based analysis was conducted using CFD software. UNLETB was modeled using FLOW3D-Hydro, and a comprehensive parametric study was conducted to obtain the hydrodynamics-input parameters for the tested samples. In addition, this study trained ANN (Artificial Neural Network) with test results to conveniently discern the erosion resistance of different gradations. The ANN quickly predicted the acceptable/non-acceptable erosion characteristics of shoulder rocks with close to 99% accuracy based on three simple parameters related to gradation (D10, D30, and D60).