석션이력을 고려한 불포화토 거동 특성

Abstract

Many geotechnical problems are occurred when the ground is to a unsaturated condition. This unsaturated soil is more difficult and complicated than a saturated soil in understanding ground behavior characteristics. Therefore, various studies and researches are required about unsaturated soil. In order to do that, it is necessary to obtain the soil water characteristic curve which shows nonlineer relationship between matric suction and volumetric water contents. In this study, an automated soil water retention curve measurement apparatus was introduced and used to investigate an accurate and expeditious soil water characteristic curve. Joomunjin sand with 75% relative density was used and the test was performed both drying and wetting processes to get a more accurated soil water characteristic curve. The test results showed different phenomena between soil water characteristic curve of a drying process and soil water characteristic curve of a wetting process.

Stress state of unsaturated soil is represented by suction stress chracteristic curve which is closely related with soil water chracteristic curve. Therefore, without accurated information about soil water characteristic curve, it is difficult to understand the strength of unsaturated ground. In this study, an accurated suction stress characteristic curve was induced through the soil water characteristic curve parameter. In addition, unsaturated infinite slope consisted of Joomunjin sand was modeled to investigate on the effect of suction stress on the strength of unsaturated ground.