When to use: Size shallow footings (spread, strip, mat) by computing the soil's ultimate bearing capacity. Uses Terzaghi's equation qu = c·Nc + q·Nq + 0.5·γ·B·Nγ with shape factors for strip, square, and circular footings. The bearing capacity factors Nc, Nq, and Nγ are functions of the soil friction angle φ. Allowable bearing = qu / FS (default FS = 3). Account for the groundwater table, which reduces effective unit weight and bearing capacity.