Dynamic Properties of Subgrade Soils,Including Environmental Effects.

摘要

Three fine-grained soils,varying in clay content between 20% and 70%,were tested in a unique repetitive loading apparatus to determine how soil suction,temperature,and stress state affect the resilient modulus and residual strains expected under highway and railroad loadings. In developing equations to predict these dynamic properties,three values of soil suction,stress intensity,and temperature were used in tests of each of the three soils in a statistically designed experiment. A fundamental change in the behavior of the tested soils from 'effectively saturated'to 'effectively unsaturated'occurs at a soil suction corresponding to two percent dry of the optimum moisture content. The critical soil suction is directly related to the clay content of the soils. This relation has important implications for the climatic design and stabilization of highway pavements and railroad grade crossings.