|Budget Amount *help
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 2000 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1999 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Fiscal Year 1998 : ¥1,400,000 (Direct Cost : ¥1,400,000)
By this financial support, the first objective of this research is successfully achieved as follows ; The failure mechanism of slope surface subjected to rainfall, is expressed by three stages model, 1. Descent of wetting front, 2. Appearance of under-ground water, and 3. Failure of slope surface layer.
The second objective was to clarify the effect of plants covering the slope. However, it cannot be completed, because the time is not sufficient, though the effects of plant are to change the seepage characteristic and to reinforce the surface soil layer.
The slope soils are not so homogeneous as alluvial soils. Then, how to determine the soil parameters is the other important problem. In this research some field test methods including new ones were used. Although some conditions of field test to determine the parameters were suggested, development of practical methods will be one of the future themes.