Document Type : Original Article
Authors
1
Professor, Faculty of Engineering, Department of Civil Engineering, Urmia University, Urmia, Iran
2
Ph.D. Student, Faculty of Engineering, Department of Civil Engineering, Urmia University, Urmia, Iran
10.22065/jsce.2024.416107.3218
Abstract
Undrained behavior of sand containing fine particles is a challenge in geotechnical research. In this article, the effect of low clay content (kaolin) on the anisotropic behavior of sand is studied. In the technical literature, there are different data about the effect of fine particles, especially in high percentages, but there have not been enough studies in low clay content and anisotropic conditions. For this purpose, 30 undrained tests are performed using a Torsional Shear Hollow Cylindrical Apparatus (TSHCA) with constant (α) and (b) values on Firoozkuh sand. The specimens had kaolin contents of 0, 3, 5, 7 and 10%, and the inclination angle (α) is varied from 15o to 60o. The specimens are prepared by dry deposition method (with funnel) and are consolidated under the P'c= 100 and 200 kPa. The results of the experiments show that increasing the (α) leads to more contractive behavior in sand. By adding clay particles to the host sand up to 3% in the angle of 15o and 30o, the peak strength of the sample is increased, and then with the increase of clay content up to 10%, the strength of the sample is decreased. But at α = 60o, with the addition of 5% clay, a decrease in the peak strength is observed and with a further increase in the percentage of clay, unlike the angles of 15o and 30o, an increase in the peak strength of the sample is observed, so that at 10% clay, the strength of the sample is higher than the host sand, which is the behavior can be attributed to the adhesive nature of clay particles and resistance to tensile loading. By increasing the clay content, the anisotropic behavior index is decreased.
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