Evaluation of the shear strength and deformation characteristics of unsaturated soils
In order to prevent and reduce ground disasters in unsaturated earth structures (slope, levee, embankment, etc.) caused by a rainfall, it needs to grasp the failure mechanism of soil structures due to the rain infiltration. For this, the shear tests with the water retention test in the laboratory are carried out according to the confining stress state reproducing the state of ground as well as the deformation mode of soil structures. The shear strength and deformation characteristics of the soil structures are examined based on the obtained results.
Applicability of water repellent soil to overlayer of capillary barrier using laboratory model test
According to the past research results, since the maximum division length (LD) in the laboratory model experiment is less than 300cm, it would be difficult to realize the application to unsaturated ground structures. Thus, laboratory model tests for the capillary barrier (CB) using the wettable and water repellent soils according to rainfall condition in this study are performed, and the applicability of the water repellent soil based on the obtained results is examined. It is expected that the more stable unsaturated ground structure would be realized by applying the water repellent soil to the sand layer of the CB system.