A square footing shown has a dimension of 1.0 m x 1.0 m has its bottom 2.5 i. below the ground surface. Angle of friction is 30' with Ne = 35, Ng 22 and %3D %3D Ny 19. Unit weight of soil is 18.1 kN/m with a cohesion of 15.7 kN/m". 3 Saturated unit weight of soil is 19.3 kN/m. Use factor of safety of 3. Calculate the allowable load that the footing could carry. O If there is no gronnd water table below the foundation. @ If the ground water table is located at 0.2 m. below the foundation. O If the ground water table is located at the bottom of the foundation. OIf the water table is located at 1.2 m. below the ground surface.

A flexible circular footing of radius R carries a uniform pressure q. Find the depth (in terms of R) at which the vertical stress below the center is 20% of q.

A square footing (B B) must carry a gross allowable load of 1160 kN. The base of the footing is to be located at a depth of 2 m below the ground surface. If the required factor of safety is 4.5, determine the size of the footing. Use Terzaghis bearing capacity factors and assume general shear failure of soil. Given: = 17 kN/m3, c = 48 kN/m2, =31.

A shallow square foundation for a column is to be constructed. It must carry a net vertical load of 1000 kN. The soil supporting the foundation is sand. The standard penetration numbers (N60) obtained from field exploration are as follows: FIG. 17.15 The groundwater table is located at a depth of 12 m. The unit weight of soil above the water table is 15.7 kN/m3, and the saturated unit weight of soil below the water table is 18.8 kN/m3. Assume that the depth of the foundation will be 1.5 m and the tolerable settlement is 25 mm. Determine the size of the foundation.

Repeat Problem 5.1 with the following data: B = 1.5 m, L = 1.5 m, Df = 1 m, H = 0.6 m, = 35, c = 0, and = 15 kN/m3. Use FS = 3. Refer to Figure 5.2 and consider a rectangular foundation. Given: B = 1.5 m, L = 2.5 m, Df = 1.2 m, H = 0.9 m, = 40, c = 0, and = 17 kN/m3. Using a factor of safety of 3, determine the gross allowable load the foundation can carry. Use Eq. (5.3).

Redo Problem 16.13 with the following data: gross allowable load = 184,000 lb, = 121 lb/ft3, c = 0, =26, Df = 6.5 ft., and required factor of safety = 2.5. 16.13 A square footing (B B) must carry a gross allowable load of 1160 kN. The base of the footing is to be located at a depth of 2 m below the ground surface. If the required factor of safety is 4.5, determine the size of the footing. Use Terzaghis bearing capacity factors and assume general shear failure of soil. Given: = 17 kN/m3, c = 48 kN/m2, =31.

A 2 m 3 m spread footing placed at a depth of 2 m carries a vertical load of 3000 kN and a moment of 300 kN m, as shown in Figure P6.14. Determine the factor of safety using Meyerhofs effective area method. Figure P6.14

The following table shows the boring log at a site where a multi-story shopping center would be constructed. Soil classification and the standard penetration number, N60, are provided in the boring log. All columns of the building are supported by square footings which must be placed at a depth of 1.5 m. Additionally, the settlement (elastic) of each footing must be restricted to 20 mm. Since the column loads at different location can vary, a design chart is helpful for quick estimation of footing size required to support a given load. a. Prepare a chart by plotting the variation of maximum allowable column loads with footing sizes, B = 1 m, 1.5 m, 2 m, and 3 m. Use a factor of safety of 3. b. If the gross column load from the structure is 250 kN, how would you use this chart to select a footing size? c. What would be the design footing size for the column in Part (b) if you use Terzaghis bearing capacity equation? For the well graded sand, assume that = 33. Use Fs = 3. d. Compare and discuss the differences in footing sizes obtained in Parts b and c.

It is proposed to place a 9 ft 9 ft foundation at 6 ft depth in a sandy soil, where the average N60 is 25 and the unit weight is 115.0 lb/ft3. Using Meyerhofs expressions presented in Section 9.6, estimate the allowable net pressure that would give 1.2 in. of settlement.

Repeat Problem 20.2 based on limit state design, using the factors given in Table 20.4. 20.2 A continuous foundation is required in a soil where c = 10 kN/m2, =26 and = 19.0 kN/m3. The depth of the foundation will be 1.0 m. The dead load and the live load are 600 kN/m and 400 kN/m, respectively. Determine the required width for the foundation based on allowable stress design with FS = 3, using Eq. (16.3) and Table 16.1.