How is the strength of soil determined in the Unconfined Compression Test?

The strength of soil in the Unconfined Compression Test is determined through axial compression of the soil sample. In this test, a cylindrical soil specimen is subjected to axial loading until failure occurs. The applied load is increased until the maximum load is reached, which corresponds to the strength of the soil. The test does not involve any confining pressure, hence the term "unconfined." By observing how much stress the soil can withstand before failure, one can directly assess its strength in a straightforward manner. The axial compression method is critical because it mimics the conditions under which soil often experiences loads in real-world applications, such as foundations or earth structures. This approach provides a clear and direct measurement of soil strength without the complexities introduced by additional confining stresses or dynamic loading.