A concrete pile 20 m long having a cross section of 0.46 m × 0.46 m is fully embedded in a saturated clay layer. For the clay, given: Yat = 18 kN/m², = 0, and Cu = 80 kN/m?. Determine the allowable load that the pile can carry (FS = 3). Use %3D the A method to estimate the skin resistance.

A driven closed-ended pile, circular in cross section, is shown in Figure P 9.4.Calculate the following.a. The ultimate point load using Meyerhof’s procedure.b. The ultimate point load using Vesic’s procedure. Take Irr = 50.c. An approximate ultimate point load on the basis of parts (a) and (b).d. The ultimate frictional resistance Qs. [Use Eqs. (9.40 (L' ≈ 15 D)) through (9.42), and take K = 1.4 and ẟ' = 0.6 Φ'.]e. The allowable load of the pile (use FS = 4).

1) A precast concrete pile with a cross-section of 350mm x 350mm is embedded in sand. The length of the pile is 15 meters. Assume that ysand= 15.8 kN/m², Øsand= 35°, and the relative density of sand is 70%. Estimate the allowable pullout capacity of the pile (FS=4). X

7. If a 45 cm diameter pipe pile is driven into clayey soil to a depth of 12 m. (a) what would the allowable load capacity (Q) be? The water table is 2 m below the ground surface and the soil profile consists of two clay layers (refer to the figure below). Use the ß method to calculate skin friction and the R=30° for all clay layers. (b) Explain how you selected FS value you use. 12 m ▶ 9m 2m 45 cm Y = 18.5kN/m³ = 30kN/m² Ysat = 19kN/m³ C₂ = 30kN/m² Ysat = 20kN/m² S = 60kN/m²

7. If a 45 cm diameter pipe pile is driven into clayey soil to a depth of 12 m. (a) what would the allowable load capacity (Q) be? The water table is 2 m below the ground surface and the soil profile consists of two clay layers (refer to the figure below). Use the ß method to calculate skin friction and the R=30° for all clay layers. (b) Explain how you selected FS value you use. 12 m 9m 2 m 45 cm Y = 18.5kN/m²³ C= 30kN/m² Ysat = 19kN/m³ Cu = 30kN/m² Ysat = 20kN/m² S = 60kN/m²

114 A driven closed-ended pile, circular in cross section, is shown in Figure P11.4. Calculate the following: a. The ultimate point load using Meyerhof's procedure. b. The ultimate point load using Vesic's procedure. Take I,, = 50. e. An approximate ultimate point load on the basis of parts (a) and (b).

2. Consider a group of 450 mm x 450 mm reinforced concrete piles were driven into thick loose sand layer with the average unit weight and internal friction angle of 16 kN/m3 and 30°, respectively. Estimate the group pile capacity with the arrangement as shown in Figure Q2 if the length of pile embedment is 30 m assuming ground water table is far below the ground surface. Use 8 = 0.80 and K = 1.5Ko. 3B 3B 3B 1 3 3.5B b 'P 9. 10 11 a 3.5B 2 4 1.5B 1.5B 1.5B 1.5B 1.5B 1.5B Figure Q2

Questions A group of 16 piles (4 in each row) was installed in a layered clay soil deposit shown below. The diameter of each pile is 500 mm and their c/c distance is 1m. The length of the pile group is 18m. Estimate the safe load capacity of the group with a factor of safety of 2.50. The adhesion factor (a) between the pile and soil in each soil layer are shown in the figure. 8 m 10 m C= 25 kPa;= 0°; a = 1.0 C₁= 40 kPa;p= 0; a = 0.7 TTTTTT Soil Profile O O O boor Plan View of pile group

● ● ● Example: 25/1 Consider a concrete pile that is 0.305 m x 0.305 m in cross section placed in sand. The pile is 15.2 m long. The following variations of N60 with depth. are the Estimate Q, using: - Estimate Qf for the pile using: Meyerhof (1976) equation Briaud et al. (1985) - Meyerhof (1976) equation Briaud et al. (1985) - • Determine the allowable load- carrying capacity of the pile based on Meyerhof's method and Briaud's method. Use a factor of safety of 3. Depth below ground surface (m) 1.5 3.0 4.5 6.0 7,5 9.0 10.5 12.0 13.5 15.0 16.5 18.0 19.5 21.0 Neo 8 10 12 14 18 11 17 20 28 29 32 30. 28