Abstract
The use of concrete for hydraulic structures has special requirements for water and its penetration through the concrete, and the effect of different aggressive agents on the concrete and its components. The requirements are much higher on permeability and durability than in the case of mechanical properties. While in the case of mechanical effects, stress concentrations are greater in region of higher quality concretes (rigidity and strength), the water flow line follow the weaker planes of increased permeability.
This paper reviews typical values of design seepage coefficient from literature and also uses the experimental results of a laboratory study done for clay-cement concrete material. The clay-cement concrete studied was designed to be a low-strength material and its properties fall between those of soil and concrete. The material may be used as anti-seepage material in the foundation and diaphragm wall in earth dams, and canal lining in channel constructions. The three main design criteria considered for anti-seepage requirements, i.e. permeability, deformity, and long-term performance are used in the dam analysis with emphasis on water permeability. Water flow effect in hypothetical earth dam cases were assessed using a finite element-based software program to determine the influence of the design water permeability of cut-off wall based on the seepage regime that develops as a result of the barrier construction.
It was found that construction of an anti-seepage barrier is effective in reducing the hydraulic gradient, even if the permeability coefficient of the barrier is several orders of magnitude high.
Results also indicate that clay-cement concrete anti-seepage effect potentially gives high performance. This study may contribute a better understanding of the fluid flow characteristics in dams having a cut-off wall for improved practices and anti-seepage materials.