Which of the following statements is the correct statement related to shear strength testing of soil? 

Explanation:

Shear Strength Testing of Soil

Shear strength testing of soil is crucial for understanding the soil's ability to resist shearing forces, which is essential for the design and stability of various engineering structures. Different tests are used to determine the shear strength of soils, and the choice of test depends on the soil type and the conditions in which it is tested.

Analyzing the Given Options

1. "Unconfined compression test can be conducted on fissured clays." (Incorrect)

   • The unconfined compression test is not suitable for fissured clays because the presence of fissures can lead to misleading results due to uneven distribution of stress.

2. "Sensitivity of the soil can be determined by both vane shear test and unconfined compression test." (Correct)

   • Sensitivity, which measures the ratio of the undisturbed to the remolded shear strength of the soil, can indeed be determined using both the vane shear test and the unconfined compression test.

3. "The unconfined compression test is a special form of a direct shear test." (Incorrect)

   • The unconfined compression test is not a form of the direct shear test. It is a separate test where a cylindrical soil sample is subjected to axial compression without any lateral confinement.

4. "Vane shear test can be performed only in the field." (Incorrect)

   • The vane shear test can be performed both in the field and in the laboratory. It is used to measure the undrained shear strength of cohesive soils.