Structural Behavior of Partial Seepage Barriers for Variations in Depth of Pervious Stratum

Abstract

In diversion structures, founded in pervious soils, suspended type cut-off walls or partial seepage barriers are used to handle destabilizing forces such as uplift pressure and exit gradient. Numerical study using FEM software is conducted to ascertain the structural behavior of cut-off walls for variations in depth of pervious soil stratum in relation to the cut-off wall depth. On observing normalized displacement plot, displacement pattern and bending moment pattern in both cut-off walls are congruent for a particular depth ratio, irrespective to their depth. The cut-off walls with similar depth ratios behave similarly with disregard to its actual depth. In all cases, displacement and bending moment in downstream wall are higher than in the upstream cut-off wall. It is also observed that the ideal depth ratio in terms of reduced structural requirement for both upstream and downstream cut-off is 0.60.KeywordsSeepage barriersSuspended type cut-off wallsDiversion damsNumerical modeling