Direct-Shear Test
To perform the direct-shear test, a soil sample is confined within a split brass housing, and loaded from above by means of a roller pushing down against the cover plate (that load is provided by regulated air pressure) . The top half of the confinement housing is slid to the right, and the force required to do so is determined by micrometer-measurement of the deflection of the proving ring (that ring, and the micrometer, are in the background). The micrometer in the foreground measures the shearing movement.
Direct-Shear Test
To perform the direct-shear test, a soil sample is confined within a split brass housing, and loaded from above by means of a roller pushing down against the cover plate (that load is provided by regulated air pressure) . The top half of the confinement housing is slid to the right, and the force required to do so is determined by micrometer-measurement of the deflection of the proving ring (that ring, and the micrometer, are in the background). The micrometer in the foreground measures the shearing movement.