Investigations To Develop Field Stabilization Methods To Mitigate Surficial Slope Failures

Abstract

Surficial slope failures induced by rainfall have been studied for many years. Current research supported by The United States Army Corps of Engineers (USACE) is undertaken at the University of Texas at Arlington on two sites, Joe Pool Dam and Grapevine Dam located in the Fort Worth district. The objective of the project is to find the best stabilization method to mitigate those failures. A testing area of 5 sections (one control and four treated) was established on each site with used admixtures of 20% compost, 4% lime with 0.30% polypropylene fibers, 8% lime with 0.15% polypropylene fibers, and 8% lime. Based on the previous analysis (Dronamraju et al., 2008), the 8% lime with 0.15% polypropylene fibers was found to be the most effective admixture to prevent surficial failures. Progresses have been successfully reported based on field performance and numerical modeling with residual saturated soil properties. However, studies done by previous researchers have proved that the fully saturated soil conditions do not quite properly describe the real soil behavior in reality. The fully softened shear strength is most likely the dominant condition of soil exposed to the wetting and drying cycles. Furthermore, this research highlights the beneficial usage of treatments on slope stability based on Fully Softened Shear Strength aspect. A complex reliability analysis based on Lab-Testing data is also conducted to give better judgment on the effectiveness of all the treatments on slope stability.