Deformation Characteristics of Piedmont Residual Soils

Abstract

Site investigations conducted at the North Carolina State University Research Farm and adjacent construction sites provided the database to study the soil profile and deformation characteristics of Piedmont residual soil. The database includes both laboratory and in-situ test results. The laboratory testing program was composed of oedometer, stress path, triaxial multistage compression, resonant column, and torsional shear tests. In-situ testing included standard penetration tests, dilatometer tests, and pressuremeter tests with Menard and push-in types. A typical soil profile is defined based on Martin's classification system. Test results from triaxial multi-stage compression, resonant column and torsional shear tests show that residual soil's decay pattern of normalized shear modulus with shear strain is similar to and lies between those of sands and San Francisco Bay Mud. The study of soil's compressive stiffness shows that pressuremeter modulus,