Review of Relative Density Principles. Relative Density principles apply to compaction of relatively clean, coarse-grained soils. Relatively clean usually taken to be less 12 % or less finer than the #200 sieve. Important for compaction study of filters.
Understand basic tests to obtain reference densities.
Use 1 point compaction test in design and quality control
Summarize minimum and maximum index density tests
Detail the importance of water content in compacting clean sands and gravelsObjectives
Sand dropped no more than 1”
Sample densified by vibration
Measure D height to determine new gd
Plate on which weight sits during vibration
Diagram below illustrates a relative density of about 40 %
gD70 = 1.075 x gd 1pt -9.61, for RD70 and gd 1pt in lb/ft3
gD50 = 1.07 x gd 1pt - 12.5, for RD50 and gd 1pt in lb/ft3
Chart is for silty sands (SM)