MATHEMATICAL APPROACH FOR ESTIMATING THE STABILITY OF GEOTEXTILE-REINFORCED EMBANKMENTS DURING AN EARTHQUAKE

The Bishop's method gives a safety factor of circular slip surfaces in excellent agreement with those given by the reliable bi-dimensional slices analysis methods such as Spencer, Janbu or Morgenstern and Price methods. However, several significant disturbing factors are not considered by the simplified or rigorous Bishop's method on which depends a lot of commercial computer programs. This paper discusses a mathematical approach to take into account changeable values of cohesion and friction angle in the Mohr-Coulomb criterion in order to consider the reduction of intrinsic characteristics; adapt a new parameter (F-s) to take into account the behavior under seismic solicitations, introduce a force (r) to take into account the of infiltrated part of water. Finally stabilizing forces generated by the geotextile layers (Geo) are statically engaged in Boshop's polygon of forces. The result shows that the seismic factor gives the main disturbing force to the slope equilibrium; whereas the geotextile action gives the main stabilizing force. In other words, this modified Bishop's method is proposed to calculate cases for which the original method could not be used.