EFFECT OF DISCONTINUOUSLY LONGITUDINAL ARRANGEMENT OF DRAIN LAYER ON REDUCTION OF PHREATIC SURFACE IN RIVER LEVEE

Abstract

 It is necessary to reduce the cost for reinforcement technology of river levee against infiltration. This study aims to conduct 3D permeability numerical analysis to investigate the effect of discontinuous arrangement of drain layer in the longitudinal direction on the reduction of phreatic surface in river levee. In the numerical analysis, we set a model levee with 100 m long and 5.0 m high. The results indicated that discontinuous arrangement of drain layer can reduce the phreatic surface in the cross section with and without the drain layers, showing that the effect of the drain layer diffuses in the longitudinal direction. It was also found that appropriate arrangement of the drain layers in the longitudinal direction can be a cost-effective reinforcement technology against infiltration.