Resilient Characteristics of Dune Sand

Resilient-modulus tests were performed on a laboratory compacted dune sand following the standard test procedure described in the 1982 AASHTO Designation T 274-82 . The samples were prepared by impact- and vibratory-compaction methods. Impact-compacted samples were prepared using standard Proctor energy. Vibratory-compacted samples were prepared using a vibration table generating vibrations of 60 Hz at a peak-to-peak amplitude of 1.73 mm (0.0681 in.). Compaction curves by impact and vibratory compaction are identical at lower water contents, but vibratory compaction produces comparatively higher dry density at increased water content. At the same water content and dry density, a vibratory-compacted specimen exhibits significantly less permanent deformation and about 40% larger resilient modulus than an impact-compacted specimen. The compaction water content has little effect on the resilient properties of dune sand. The resilient modulus increases linearly with dry density for relative compaction of 95–103%. A regression equation and a design chart to estimate the resilient modulus were developed.