| dc.description.abstract | The objective of this research was to improve existing knowledge on soil erosion testing, modelling, classification, mitigation, and prediction of natural and improved soils for dam and levee engineering. An improved testing and data reduction procedure for the in-situ Borehole Erosion Test (BET) is proposed based on performing the BET at 13 locations. Nearly 250 erosion tests on natural and improved soils were performed in the Erosion Function Apparatus (EFA) in the Soil Erosion Laboratory at Texas A&M University to better understand the behavior of natural and improved soils under various conditions. Seventy-five tests out of the 250 EFA tests were performed on improved soils such as grass covered soils, lime-treated soils, enzyme-treated soils as well as riprap covered soils. All soils were classified for their erodibility including obtaining the entire erosion curve (erosion rate versus velocity and erosion rate versus shear stress), the critical shear stress and critical velocity, the erosion modulus. The efficiency of soil improvement methods was compared, and advantages and limitations for each method were identified. A new erosion model and erosion classification was developed and applied to natural and improved soils. The automated excel spreadsheet called TAMU-PEM (Prediction of Erosion Movement) was created which allows to estimate how much erosion can take place given the erosion function of the soil and the velocity vs time hydrograph for the water. The 250 erosion tests performed during this research were added to the existing TAMU-Erosion spread sheet along with an improved procedure. A risk chart was proposed for earth dams, tailing dams, levees, and some other structures affected by erosion. | |
