Mojtaba Ahmadabadi - Lecturer and faculty member at Shiraz Art Institute of Higher Education, Shiraz, Iran
Gholamreza Namvarchi - The member of the Board of Contruction Engineering Organization of Fars province, Shiraz, Iran
Mehdi Sharifi - Consulting Engineers of Bastan pasargad Civil Development
Morteza Rezaei - Consulting Engineers of Bastan pasargad Civil Development

In this paper, based on limit equilibrium principles and using horizontal slices, a simple solution is presented to calculate normal stress in the slopes. Using γH relationship is suitablein vertical slopes, but in non-vertical slopes, using γH relationship is associated with a lot oferrors. Previous researchers have presented a complex relationship, the use of which is onlyuseful in non-cohesive soils. In this method which is derived from the horizontal slicesmethod, primarily, the horizontal slices above the rupture line are divided into a number ofhorizontal slices. In each system, four equations and four unknowns are formed; solving theso-called equations system, horizontal shear force between the slices and the vertical forcebetween the slices are obtained for each slice. Dividing the vertical force between the slicesby the surface, the average normal stress value is obtained. Specific innovation of this study isto present normal stress for cohesive-frictional soil slopes. In addition, the current study set topresent charts to state the shear strength and normal stress relationship, the values of whichcan be calculated with no need for calculations.

shear strength, normal stress, soil slopes, cohesive- frictional, soil internal friction angle