Which test is most suitable for evaluating undisturbed and remolded soil sensitivity?

The Vane Test is the most suitable for evaluating undisturbed and remolded soil sensitivity because it specifically measures the in-situ shear strength of saturated cohesive soils. This test involves inserting a four-blade vane into the soil and rotating it, allowing for the direct measurement of the soil's resistance to shear.

The sensitivity of soil is essentially a ratio that compares the undisturbed shear strength to the remolded shear strength. The Vane Test not only provides data on undisturbed conditions but can also be used to assess how the soil behaves after disturbance, making it ideal for determining sensitivity. The ability to evaluate both states in one test allows engineers to understand the potential behavioral changes of the soil under different conditions, which is critical in foundation design and stability analysis.

Other tests like the Unconfined Compression Test and Triaxial Test are useful for measuring shear strength in different contexts, but they do not directly measure sensitivity in the same manner as the Vane Test. The Direct Shear Test, while useful for understanding soil behavior under applied shear load, is not focused on evaluating soil sensitivity and does not provide real-time measurements in the same way as the Vane Test does.