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Lab Services: Soil testing

Lab Services: Soil testing

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Test Method Title

Standard Test Method for Consolidated Undrained Direct Simple Shear Testing of Cohesive Soils

Reference Number

ASTM D6528



Test Property

Shear strain, shear stress, shear modulus

Description of Test

In this test method a specimen of cohesive soil is constrained axially between two parallel, rigid platens and laterally, such that the cross sectional area remains constant. The specimen is loaded axially and allowed to consolidate one-dimensionally, in steps, allowing for the dissipation of the excess pore water pressures. The specimen is sheared by displacing one platen tangentially relative to the other at a constant rate of displacement and measuring the resulting shear force. The shear strength of a specimen depends of the soil type, normal consolidation stress, time of consolidation, rate of strain and prior stress history of the soil.

Preferred Test Sample Size

Number of Test Specimens


Test Specimen Size

Minimum dimensions; diameter of 45 mm x 12 mm height, with a height to diameter ratio of 0.4 or less and the largest particle size 1/10 the diameter of the specimen.


clays, cohesive soils, consolidated undrained test, consolidation test, constant volume test, recompression, shear apparatus, shear strain, shear strength, shear test, simple shear, undrained shear tests

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