THE NEW FORMULA OF THE LIMIT EQUILIBRIUM HORIZONTAL TOP VERTICAL SLOPE

This paper presents new formulas related to limit equilibrium analysis of the vertical slopes and its applications in slope engineering design. The depth of tension crack and critical slope height are derived from differential equations, which are different from those given by Rankine "state of stress" earth pressure theory. Regardless the difference between the new method presented in this paper and the Rankine theory, their calculation results are almost identical. The results also confirmed that the sliding body slides along the limit angle of the slide. The relationship between critical crack depth and distance from the slope edge, integrating with location of the sliding plane maximum, once can determine the basic (free segment) length of a ground anchor or an earth bar. In addition, the C value could be determined if the both crack depth and distance from the slope edge were measured. The authors also confirmed that active earth pressure equals to the driving force for slide. The new formula reflects physical characterization and reality more closely. In realizing that critical slope height is reduced after a crack is generated within the slope, the authors presented several guidelines for design and construction of vertical slopes.