Environmental influences on the engineering behavior of unsaturated undisturbed subgrade soils: effect of soil suctions on resilient modulus

摘要

This study evaluated the effect of soil suction on resilient modulus of undisturbed subgrade soil specimens col-lected from a section located on I-40 in Canadian County, Oklahoma. A total of 18 undisturbed specimens were tested for resilient modulus (M_R) and soil suction. AASHTO 2002 Design guide M_R predictive model was used and evaluated for its reli-ability in predicting M_R values. Findings from M_R and soil suction tests showed that M_R increased as total and matric suctions increased. The variation of M_R with both suctions revealed the same trends. Additionally, an existing M_R-stress-suction model was modified to evaluate the variation of M_R with suction and stresses. The modified model was a reliable predictor of M_R values of unsaturated subgrade soils.