Factors Affecting Coefficient of Earth Pressure <i> K _o </i>

Abstract

The coefficient of earth pressure at rest can be accurately determined by conducting constant stress ratio tests in the triaxial apparatus (interpolation method). This method is stress controlled and thus the errors in strain measurements do not interfere with the test procedure and can be corrected for after the test is finished. Strains in a Ko increases with: (1) the increase in porosity, decrease in φμ, crushing; and (2) the increase in the modulus of elasticity of the particles mineral. The effects of allowing small lateral strains and the restraining direction on the value of Ko are examined.