Mechanism Study On The Reinforcement Of EN-1 Ionic Soil Stabilizer To The Loess Slope

The protective measures for highway subgrade slope are an important component of soil and water conservation on highway and the study on them have important significance to the construction of highway soil and water conservation. Through the laboratory test and theory analysis, this text studied the influences of the EN-1 contents(0, 0.01%, 0.05%, 0.10%, 0.15%, 0.20%)on physical and chemical properties for tier soil and loessal soil in the 0-30 cm and 30-100 cm layers, including soil water availability, structural stability, permeability, collapsibility, organic matter and acidity,analyzed soil erosion law,overland flow characteristics and scour resistance with six EN-1 contents and five EN-1 depths,and selected the appropriate EN-1 content and depth. By stepwise regression analysis to establish wash erosion prediction models, and explained the reinforcement mechanism of EN-1 plasma soil stabilizer to the slope soil. Main results are as follows:1. EN-1 reduces the effectiveness of soil moisture, the higher the content, the greater the effect was, the impact on tier soil was slightly larger than that in the loessal soil and on the upper soil (0-30 cm layer) was significantly higher than that in the subsoil (30-100 cm layer). For the tier soil and loessal soil in the 0-30 cm, it was greater benefit to improve soil structural performance since the content was greater than 0.15%, and the 0.20% content was most excellent; it was greater benefit to improve soil structural stability since the content was greater than 0.01%, and the 0.15% content was most excellent. For the loessal soil in the 30-100 cm, they were useful to improve soil structure and stability by using EN-1, and the best soil structure was at 0.01% content, the optimal structural stability was at 0.20% content.2. When the EN-1 contents were from 0.10% to 0.15%, the soil permeability was the largest. The soil resistance to collapse was significantly improved by using EN-1, when the EN-1 contents were more than 0.15% for tier soil, the soil resistance to collapse was more significantly increased; when the EN-1 contents were 0.10% for loessal soil, the soil resistance to collapse was more significantly increased. The higher the content, the higher the soil organic matter content and the lower pH value were.3. Adding EN-1 soil stabilizer into the subgrade slope soil, the mean runoff velocity was increased, and the erosion power was decreased, besides, the runoff morphology was laminar and rapid flow, the impact on the loessal soil slope runoff mean velocity was larger than that in tier soil, EN-1 had a great effect on runoff morphology on tier soil slope and little effect on loessal soil slope. Runoff and sediment yield on the slope were reduced by adding EN-1 into the subgrade slope soil, they were the lowest at the 0.10% content. EN-1 contents had a greater effect on runoff and sediment yield on the tier soil slope than that on the loessal soil slope, the impact on the upper soil (0-30 cm layer)slope runoff was significantly higher than that in the subsoil (30-100 cm layer) and the sediment yield was opposite .4. The maximum mean runoff velocity was got when EN-1 applied depth was 15 cm, while it was the minimum at 20 cm in the tier soil. The maximum mean runoff velocity was got when EN-1 applied depth was 20 cm, while it was the minimum at 10 cm in the loessal soil. The runoff morphology was laminar and rapid flow at different applied depth. The largest Re and f and the smallest Fr were got when the EN-1 applied depth was 10 cm; while the smallest Re and f and the largest Fr were got when the EN-1 applied depth was 20 cm. The deeper of the EN-1 applied, the smaller runoff was in the tier soil slope, while the larger of the runoff in the loessal, the lowest sediment yield was and the slope was the most stabilization.5. Through the stepwise multiple linear regression analysis, the models and indicators for assessing the soil erodibility from these properties was constructed, and they explained reinforce mechanisms of EN-1 to the loess slope with different soil types by. In the 0-30cm layers of tier soil, the slope was reinforced through the increasing of soil saturated hydraulic conductivity and the water-stable aggregates and the decreasing of soil collapse velocity; In the 30-100 cm layers of tier soil, the slope was reinforced through the increasing of organic matter content and the decreasing of saturation moisture content; In the 0-30 cm layers of loessal soil, the slope was reinforced through the decreasing of soil collapse velocity and PH; In the 30-100 cm layers of loessal soil, the slope was reinforced through the increasing of dry aggregates and the decreasing of soil collapse velocity and saturation moisture content. Comprehensive consideration on EN-1 soil stabilizer contents affection on soil water availability, structural stability, permeability, collapsibility, organic matter, acidity and scour resistance, the paper suggests that EN-1 soil stabilizer can be used in protection engineering of highway subgrade slope for loess region, and the optimum content is around 0.10% and depth is 20cm can increase the ability of soil resistance runoff scour of slope significantly, and it can prevent slope instability caused by slope erosion damage.