Bearing capacity problem. Figure 3.26 shows that a square shallow spread footing is designed to support a column. The load on the column, including the column weight, is 650 kN. The foundation rests in homogeneous sandy clay. Subsurface exploration and laboratory testing found that the soil’s effective cohesion is 55 kN∕㎡ and the effective friction angle is 15∘. The groundwater table is 1.2 m below the ground surface. The bulk unit weight above the groundwater table is 18 kN∕m³ the saturated unit weight below the groundwater table is 18.8 kN∕m³. Use Terzaghi’s bearing capacity theory, and assume the general shear failure.
(1) Determine the foundation embedment and design the dimensions of the spread footing. The factor of safety for bearing capacity is 3.0.
(2) Choose the foundation dimensions that are acceptable in the construction, and then calculate the allowable bearing capacity on the basis of these dimensions.
