| Abstract [eng] |
The objective of this study was to investigate the influence of silt content on the angle of internal friction of sand-silt mixtures. Silt fraction samples were collected from both natural and artificial soils, using quartz sand as a base and previously collected silt samples, mixture containing 0%, 5%, 15%, and 30% silt were prepared. These mixtures were tested for grain size distribution, pycnometer analysis, proctor compaction and liquid and plastic limit determination. To determine the internal friction angle values, direct shear tests were conducted. This method was applied to mixtures under two conditions: 1. Loose state (ID = 0), oven dried soils. 2. Maximum dry density (ID = 1), optimum moisture content (wopt) soils. Based on the tests and data analysis, it was found that soils under the first condition showed a tendency for the internal friction angle values to increase with a higher silt content in the sand. Mixtures tested under this condition also tended to compress during shearing. For mixtures under second condition, the internal friction angle tended to increase up to a 15% silt content, then decrease thereafter. It was also observed that even a relatively small amount of silt (5%) had a significant effect on the internal friction angle values. |
