NEW SLIP CIRCLE METHOD FOR ANALYSIS OF SLOPE STABILITY AND BEARING CAPACITY

Takashi Tsuchida, Kenta Mizuno and Hideto Hikiyashiki

ABSTRACT: Modifield Fellenius' slip circle method and Simplified bishop's slip circle method have been commonly used for analysis of slope stability and bearing capacity of gound in practice. However, it is well known that, in the case of sandy ground, Modified Fellenius' method underestimates the safety factor, while Simplified bishop's method overestimates the safety factor. In this study a new slip circle method is developed for the purpose of accurate analysis of sandy ground. The main conclusions are summarized as follows:
1) A new slip circle method is proposed, where the shear force-normal force ratio on lateral surface of each slice is assumed to be 1/3.5.
2) By using the proposed method, a set of bearing capacity factor of shallow foundation, N_c, N_q, N_g, which are almost same as the values of plasticity solution, can be calculated.
3) Based on the back-analyses of case records, it was examined that the safety factor for slope stability calculated by the proosed method explains actual performance of soil structures fairly wel.

Keywords: stability analysis, bearing capacity, slope stability, finite element method, circular slip (IGC: E3/E6)