Fort Creek Dam—impervious clay core

Abstract

Experience with the construction of an impervious clay core for an earth fill dam are related. For the construction of the impervious core, locally available highly plastic and sensitive glacial lake clay deposit was used. The clay was borrowed at moisture contents 16 to 18% above the optimum and placed at moisture contents 6 to 10% above optimum. The placement of the fill was controlled by checking its moisture content and the undrained shear strength both by laboratory compression tests and field vane tests. Good correlation exists between the relative density, moisture content and shear strength of the compacted material. Construction control included also the monitoring of piezometers installed in the lower half of the clay core and the foundation material. The pore pressures in these piezometers were recorded as the placing of the fill progressed and are presented in this paper. (TRRL)