花崗巖質風化土 盛土斜面의 安定檢討에 關한 硏究 = A Study on the Slope Stability Analysis of Embankment with Weathered Granite Soil

다국어 초록 (Multilingual Abstract)

Weathered granite soil which has complicate engineering properties is frequently used as a embankment material in civil works in that it is widely scattered in the hilly side of field.
We intend to investigate the physical and engineering properties of 6 kinds of weathered granite soil collected near Dae-Jeon region and to analyse the slope stability by both indoor model test and theoretical review. The purpose of this study is to check the safety factor in the canal slope embanked by weathered granite soil and to provide some data to be efficiently utilized for the safe embanking construction. The results are summarized as follows.
1. Flow limit can be easily obtained from the flow-table. This flow limit shows similar value obtained from slump test and shows higher value as the content of colored mineral is increased.
2. Strength parameter by direct shear test shows higher value than the one by triaxial test.
3. Shear strength in submerged condition shows smaller value than the one in unsaturated condition especially cohesion is so greatly decreased than internal friction angle that decreasement of shear strength comes up remarkably in submerged condition with cohesive soil.
4. Plane of sliding failure is nearly co incident with seepage line in the embanked slope with weathered granite soil. Primary sliding failure start to occur at the toe of slope when seepage flow comes up and than secondary and tertiary sliding failure continue.
5. Taking into account the seepage through the embanked slope with weathered granite soil, safety factor of formula (1) obtained by using the shear resistance from submerged direct test appear to be better one than the one obtained by using the strength parameter of cohesion and internal friction angle.