Mikasa's Direct Shear Apparatus, Test Procedures and Results

Mikasa's direct shear apparatus and test procedures are presented. This test apparatus was developed in 1960 to conduct constant volume shear tests, which correspond to undrained shear tests for saturated soils. This apparatus overcomes several defects of the traditional apparatus. The advantages of the direct shear test over the triaxial test are discussed, and typical examples of test results are presented. Some modifications of the test apparatus and procedures permitted automation of constant volume shear tests and unconsolidated undrained shear tests.