For sandy soil, the bearing capacity factor Nq is typically around 3.0, which is used in calculating the ultimate bearing capacity.

The presence of a weak layer generally decreases the overall bearing capacity because it can lead to shear failure at lower loads than would be expected from the stronger layers.

In the Terzaghi bearing capacity equation, 'q' represents the effective stress at the depth of the foundation, which is crucial for determining the bearing capacity.

In cohesive soils, the bearing capacity generally increases with depth due to the increase in effective stress.

The presence of a water table can decrease the effective stress in the soil, leading to a reduction in bearing capacity due to buoyancy effects and increased pore water pressure.

Liquefaction is the primary cause of bearing capacity failure in sandy soils during seismic events, as it can lead to a sudden loss of strength.

The primary factor influencing the bearing capacity of a foundation on cohesive soil is soil cohesion, as it directly affects the shear strength of the soil.

The recommended factor of safety for bearing capacity in foundation design is typically 1.5, ensuring a safe margin against failure.

The ultimate bearing capacity (q_u) can be calculated using the formula q_u = c*N_c, where c is the cohesion and N_c is the bearing capacity factor. For saturated clay, N_c is typically around 5. Therefore, q_u = 50 kPa * 5 = 250 kPa.

All of the listed methods (Standard Penetration Test, Cone Penetration Test, and Plate Load Test) are commonly used to determine the bearing capacity of a foundation.