The Effect of Horizontal Drainage Lengths on the Stability of a Homogeneous Earth-Fill Dam Under Seepage Conditions

Abstract

Failures can occur from seepage failure in the downstream slope of an earth-fill dam. The excessive pore pressures and seepages must be controlled to achieve the desired safety level in such dams. This safety can be provided with a horizontal drainage cover design. The essential goal of drainage system design is to increase system efficiency in reducing pore water pressures and seepage. Several calculations were made with a downstream slope cover design and downstream horizontal drainage length for homogeneous earth-fill dams. The minimum and maximum effective length of the filtered drainage system was obtained after the analyses. Moreover, the factor of safety regarding the downstream slope was calculated for the drainage system with different geometries. The results showed that the horizontal drainage length affects system performance and the seepage behavior of the dam.