ASTM D4767-11 (R2020) PDF Download

ASTM D4767-11 (R2020) is a standard test method that determines the strength and stress-strain relationships of a cylindrical specimen of cohesive soils under consolidated undrained triaxial compression conditions. The test method is applicable to saturated soils that have been fully consolidated under one set of stresses and are then subjected to a change in stress without further consolidation taking place.

The shear characteristics of the soil are measured under undrained conditions, which is representative of field conditions where soils experience changes in stress without sufficient time for drainage to occur. The test method also allows for the determination of shear strength in terms of effective stress, which is applicable to field conditions where full drainage can occur or where pore pressures induced by loading can be estimated.

The shear strength values obtained from the test method are commonly used in embankment stability analyses, earth pressure calculations, and foundation design. It is important to note that the precision of this test method depends on the competence of the personnel performing it and the suitability of the equipment and facilities used. Compliance with ASTM Practice D3740, which evaluates testing criteria, does not guarantee reliable testing.

The test method provides data that are useful for determining strength and deformation properties of cohesive soils, such as Mohr strength envelopes and Young's modulus. Generally, three specimens are tested at different effective consolidation stresses to define a strength envelope. The standard also provides guidelines for significant digits and rounding of observed and calculated values.

The standard uses the gravitational system of inch-pound units and provides additional clarification regarding the use of pounds to represent both mass and force. It also distinguishes between density and unit weight, with density given only in SI units and unit weight calculated in either SI or inch-pound units.