Abstract
This paper reports a long term stability of geogrid reinforced embankment constructed in 1995 in which it is 20m high and gradient of slope is 64°C. Formerly, the reinforced embankment was designed by two types of stability analysis based on earth pressure theory or Fellenius method. As a result, placement of geogrid was different due to a difference of shapes of slip surface and definition of safety factore in each theory. This embankment was designed by combining two theories and by using applicable soil parameters, so that an optimum placement of geogrid was determined. To verify a stability of the embankment, FE analysis assuming elastic-plastic behavior of soil is applied. This paper proposes a design method of reinforced embankment and determination of soil parameters by comparing the result of FE analysis with limit equilibrium method.