Stability analysis of embankment dams with defective internal geomembrane liners

Abstract

ABSTRACT Internal geomembranes are alternatives to traditional clay cores and upstream geomembranes. In this research, numerical analysis is performed to assess the impact of leakage through 2-D geomembrane defects such as slits, tears and faulty stitches. Five possible applications of internal geomembranes and an upstream geomembrane were modelled to compare their performance with that of clayey cores. The results show that use of upstream or internal geomembranes significantly decreases the pore pressure developed at the downstream slope thus improving its stability. The effects of leakage through both internal and upstream geomembranes on the stability of embankment slopes under steady state and drawdown at a rate, conditions were analysed. Stability of the downstream slope reduces significantly due to defective geomembranes depending on the defective seam locations. Drawdown simulations show that internal geomembranes can cause instability in steep upstream slopes of dams.