Investigating Shear Strength at Different Degrees of Saturation: A Direct Shear Approach

Understanding the shear strength of soil at different levels of saturation is necessary for various engineering applications, especially in geotechnical and civil engineering projects. The objective of this thesis is to conduct an extensive literature review of the use of geosynthetics to improve the strength of soil material, conduct laboratory testing components to assess the shear strength of soil at different water contents, and participate in the Leadership through Mentoring program to gain mentoring and leadership skills. The laboratory component focuses on analyzing the shear strength of soil samples with different water contents, specifically at 6%, 10%, 12.3%, 15%, 17%, and 19%. The soil-water mixtures were prepared with precision to achieve these specific water contents. Static compaction techniques were then employed to mold the soil samples to desired densities. The experimental setup involved subjecting the molded soil samples to a direct shear test using a direct shear machine. This apparatus allowed for the measurement of normal and shear stress, as well as shear and normal displacements during the testing process. These data were used to determine the cohesion and internal friction characteristics of the soil samples at different degrees of saturation. The results obtained from the direct shear tests revealed valuable insights into the shear strength behavior of the soil under varying saturation levels. The cohesion and internal friction parameters were found to exhibit distinct trends as the water content in the soil changed. The cohesion and internal friction parameters were found to exhibit distinct trends as the water content in the soil changed. The friction angle did not change significantly at different water contents, while the cohesion intercept trend appears to be contradicted the results reported in the literature, as there is a slight increase. The unexpected results might be due to the testing device failing after the third moisture content test. A different approach could have been taken to compact the specimens at optimum moisture content to get the same soil structure for each moisture content. These findings need to be re-evaluated based on the conclusion outlined in this report. Further research in this area could lead to enhanced models and methodologies for predicting soil behavior in real-world scenarios. In addition to the experimental tasks performed, I participated in a program to gain leadership skills through a mentoring format. The goal of the program was to help me understand my strengths and weaknesses to become a better leader. Through interactive assessments, feedback mechanisms, 3 and learning resources, I was able to understand what I was good and bad at. The weekly assessments helped me to constantly be honest with myself and evaluate myself as a student, peer, and leader. The program gave me a graduate student mentor that guided me through the process of learning how to manage projects effectively and understanding how to lead. Through the lessons learned and challenges encountered, I was able to grow and become a more efficient listener as well as analyze information better. These tools helped me to enhance my leadership skills and become a more effective and impactful leader.