The embankments on Nakdong River water system had been builded long ago. They are instability by many localized torrential downpour. So the repair and reinforcement plan of embankments are required. In this study, soil properties of relationship between physical and mechanical characteristics and geotechnical properties of the sub soil under embankments on Hwang River basin in Gyeong Sang Nam-Do are analyzed. The results of the study show the correlation of various kinds soil indexes of the sub soil under embankments. Also it could be used for database of new build, repair and reinforcement embankment. Obtained relationship was as follows ;
The generally sub soil under embankments, coarse soils are SP and SM, GP, SM-SP, fine-grained soils are almost ML.
The result of soil analysis, The average value of in situ water content, specific gravity and void ratio is larger midstream basin than downstream basin.
Considering the physical property, relationship of liquid limit-depth and plastic limit-depth showed similar form ; midstream and downstream basin. Relationship of liquid limit-in situ water content and plastic limit-in situ water content showed similar form of direct proportion ; midstream and downstream basin.
In case of mechanical property for fine-grained soils, value of undrained shear strength was larger midstream basin than downstream basin. Each sub soils under embankments were almost normal consolidation state in relationship of over consolidation ratio-depth.
In relationship of physical and mechanical property for fine-grained soils, relationship of undrained shear strength-in situ water content , undrained shear strength-liquid limit and undrained shear strength-plastic limit showed Linear. Relationship of rate of strength increase-plastic limit showed that midstream basin was direct proportion and downstream basin was inverse proportion.