Field density, gradation, and triaxial testing of large-size rockfill for little blue run dam

The results of field density and gradation tests involving large-size compacted rockfill (sedimentary rocks) were used to establish gradation and compaction requirements for large-size (38-cm-diameter) and conventional (15-cm-diameter) triaxial tests. The gradation requirements were that the gradation curves for triaxial test materials should be parallel to the corresponding field gradation curve, except for minor modifications to avoid excessive inclusion of fines. The angle of internal friction decreased as maximum particle size increased, in a manner similar to that reported by others. Extrapolation was used to check the Φ-values used in design.