Abstract
The effects of the horizontal drains on the ground water level are predicted using the three-dimensional finite element analyses of water flow through unsaturated-saturated soils. The slope stability is evaluated by the total factor of safety, using the three-dimensional elasto-plastic finite element analyses based on the shear strength reduction method. In the elasto-plastic analyses, the initial effective stress in the slope is evaluated by the distribution of pore water pressure wich has been given by the seepage flow analyses.
As indicated in this paper, in cases where the horizontal drains are constructed in inappropriate areas in the slope, the improvement of the total factor of safety is not satisfactory. It is confirmed that the analytical method presented in this paper is expected to be very effective for the evaluation of the performance of actual horizontal drains in slopes.
