Numerical analysis of seepage in earth slopes

Seepage is one of the most prominent factors in causing slope stability problems. Installation of longitudinal drainage trenches along the face of the slope can be an alternative solution to reduce the seepage.; The objective of this study was to investigate the effectiveness of the longitudinal drains in reducing the seepage, by using MODFLOW, a three dimensional finite difference groundwater flow model. The influence of various parameters on the performance of longitudinal drains was investigated. These parameters include the trench spacing (w), seepage depth (h), slope angle (theta), length of slope (L) and soil type (K). Numerical analysis was performed for both laboratory and field conditions under steady state and transient conditions.; The results demonstrate that the longitudinal drainage trenches are very effective in removing the seepage from the soil. Results also show that the transient time is relatively short for the drains to become fully functional.