Development of Revegetated Slope Stability Assessment System in South Korea

Abstract

This research was conducted to develop the revegetated slope stability assess (RSSA) system for revegetated cut-slopes in South Korea. A field survey was conducted on potential risk slopes and stable slopes using the twenty three variables. Through a nort-parametric test and a correlation analysis of the field survey results, nine variables were identified as primary determinants of slope failures. Of these variables, six variables were from the soil category, (soil porosity, soil water content, soil depth, soil tensile strength, salt concentration, and soil organic matter) and three variables were from the vegetation category, (vegetation coverage, number of trees, and vegetation community). None of the physical characteristic variables were selected as determinants. Discriminant analysis was conducted to develop evaluation indicators from nine variables. As a result, the discriminant function included four variables: soil porosity, soil tensile strength, soil organic matter, and vegetation coverage as the indicators of the discriminant function. The data of vegetation community was excluded from the discriminant analysis as it was a nominal scale but used for the final screening of stability using the relationship between the discriminant score and vegetation community. RSSA system was developed by combining these two processes. Although RSSA system is not a complete system for slope stability assessment, it is very practical for revegetated slope stability assessment because it requires relatively few indicators which can be easily measured. Therefore, it should be useful for the initial assessment or supplemental assessment with the integrated slope stability assessment system to be developed in the future.