2020 Volume 76 Issue 3 Pages 221-234
To properly construct impermeable embankment, typically the core zone of earth-fill dam, it is required to ensure sufficiently low values of the coefficient of hydraulic conductivity, k. To this end, the grading characteristic of backfill and the moisture content and dry density after compaction in the field are measured and controlled. This conventional method is, however, time-consuming therefore restricting the number of measurements. To develop an indirect but much faster method that can control the field k values to be sufficiently low by upper-bound control of field soil stiffness index, S, we performed a comprehensive series of laboratory and field tests changing the compaction energy level, CEL, and particle size distribution characteristics related to the construction of a 139 m-high fill dam. It was confirmed that, when the CEL and the soil type are controlled to be identical to those used in field tests by which the allowable upper bound of S is determined, the k value is kept lower than the allowable upper bound if all measured S values are kept lower than the specified upper bound.
