The Direct Shear Test is a laboratory procedure used to determine the shear strength of soil. In this test, a soil sample is placed in a shear box and subjected to a controlled normal load. The box is then pulled apart horizontally until the soil fails, allowing for the measurement of the shear force at failure. This test helps engineers understand how soil behaves under different loading conditions, which is crucial for construction projects. The results are used to inform the design of foundations, retaining walls, and other structures that rely on the stability of the underlying soil.