Drainage under saturated condition

The effective shear strength can be tested in the laboratory by means of different test procedures such as a the direct shear test, simple shear test and the triaxial test. Normally testing is performed on saturated material. For every test setup, a clear distinction must be made between testing the material under drained or undrained conditions. From this point of view triaxial tests, type CU (Consolidated Undrained) or CD (Consohdated Drained) allow for a better control of the drainage conditions and porewater pressures than for instance shear box tests. For further elaboration on these types of tests, reference is made to textbooks on Soil Mechanics and laboratory testing (Head, 2006). 

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