The weathered sand is weathered from the granite in the San GOrge. Because of the different weathered degrees and the unstable particulate grade, it belongs to a kind of inhomogeneous material. The mathematical model for its maximum dry unit weight
ρd max and the content
ρ5 of coarse particle is established through the compacting test on the weathered sand. The figure of the three-factors, namely, compactnessd
D, in-situ dry density
ρd and content
ρ5 of coarse particle is given. Through the engineering application in the past three years the good result has been obtained.