Process Study of the Soil Stratification on Weathered Granite Slopes

Abstract

Anew classification of soil profile patterns was proposed to clarify the process of soil stratification. The distrbution and stability of soil profile patterns was investigated on weathered granite slopes.
(1) The simple dynamic cone penetration test was carried out at 156 points of weathered granite slopes in the northeast part of Aichi Prefecture. The soil profiles were expressed by penetration test. The soil profiles were classified into six patterns.
(2) The thickness of soil horizons and the distribution of soil profile patterns was investigated on the test field.
(3) Amodel that soil profile patterns are formed by creeping and deposition of soil and weathering of the underlaid materials on a unit slope was constructed. The process of soil stratification has four course and main course on each slope forms was presumed by the distrbution of soil profile patterns.
(4) The test field map was divided into 440 cells with 5m × 5m quadrates. The subsurface water level of each cell was estimated by using a runoff model based on saturated-unsaturated Darcy's law. The safety factor of each cell was computed by the infinite slope stability model.
The result showed that the process of soil stratification was different with slope forms and middle slope of convergent slope unit has the cycle of slope failure.