The purpose of applying confining pressure in a triaxial test is to simulate in-situ conditions and assess the strength of the soil under controlled stress.

Consolidation refers to the process of reduction in volume of soil due to the expulsion of water from the soil pores under load.

The plasticity index indicates the range of moisture content over which soil behaves plastically, calculated as the difference between the liquid limit and plastic limit.

The Standard Proctor Test is used to determine the maximum dry density and optimum moisture content of soil for compaction purposes.

The shear strength of saturated clay is primarily affected by effective stress, as described by Terzaghi's principle of effective stress.

Soil sampling is the primary method for site investigation, allowing for the collection of soil samples for laboratory analysis.

The Atterberg limits test is used to classify soil based on its plasticity, specifically the liquid limit and plastic limit.

The constant head test is used to determine the permeability of granular soils, while the falling head test is used for finer soils.

The Unified Soil Classification System (USCS) is an ASTM standard used for classifying soils based on their grain size and plasticity.

Cantilever walls are most suitable for granular soils as they can effectively resist lateral earth pressures with their design.