| Title |
The Effect of Surface Tension on Shear Wave Velocities according to Changes of Temperature and Degree of Saturation |
| Authors |
박정희(Park, Jung-Hee) ; 강민구(Kang, Min-Gu) ; 서선영(Seo, Sun-Young) ; 이종섭(Lee, Jong-Sub) |
| DOI |
https://doi.org/10.12652/Ksce.2012.32.6C.285 |
| Keywords |
겉보기 점착력;포화도;전단파 속도;표면장력;온도 apparent cohesion;degree of saturation;shear waves velocity;surface tension;temperature |
| Abstract |
The surface tension, which is generated in the unsaturated soils, increases the stiffness of the soils. The objective of this study is to estimate the effect of the surface tension, which varies according to the temperature, on the shear wave velocity. Nine specimens, which have the different degree of saturation (0%, 2.5%, 5%, 10%, 20%, 40%, 60%, 80%, 100%), are prepared by using sand-silt mixtures. Experiments are carried out in a nylon cell designed for the measurement of shear waves. A pair of bender elements, which are used for the generation and detection of shear waves, is installed as a cross-hole type. The shear waves are continuously monitored and measured as the temperature of specimens decreases from $15^{\circ}C$ to $1^{\circ}C$. The results show that shear wave velocities of the fully saturated and fully dried specimens change a little bit as the temperatures of specimens decrease. However, the shear wave velocities of the specimens with the degree of saturations of 2.5%, 5%, 10%, 20%, 40%, 60% and 80% continuously increase as temperature decreases from $15^{\circ}C$ to $1^{\circ}C$. Furthermore, a fully saturated specimen is dried at the temperature of $70^{\circ}C$ in order to observe the shear waves according to degree of saturation. The shear wave velocities measured at the temperature of $70^{\circ}C$ are generally lower than those measured at temperature of $15^{\circ}C$. This study demonstrates that the dependence of shear wave velocities on the temperature according to the degree of saturation should be taken into account in both laboratory and field tests. |