Question 5: A structure weighing 2500 kN (excluding pile cap weight) is to be supported on a pile...

Question 5: A structure weighing 2500 kN (excluding pile cap weight) is to be supported on a pile group (driven precast concrete piles). The soil profile is shown in figure 1. Design a pile foundation such that the maximum settlement of the group does not exceed 20 mm, and pile group is safe from shear failure of the soil. OCR for the clay till is 4 to 5 and OCR of clay shale is 6 to 8. Marks (24) (CLO) Hint: Because of high OCR value, ignore the consolidation settlement of pile group, however, immediate settlement of the pile group would occur. Deprem ground TO Solprofile Topsol Slysand 802.40 - 2700. est 0129 Nm. 18 1213.60 20 16 14.8 10 18 2016.00 Den 4-3728 est 31 m. 2407.20 16 14 16 288.4 329.60 12 13252 6630 Nm.) 36 10.83 40 (12.01 12 Figure 1 Soil profile (qu = unconfined compressive strength, w = natural moisture content)

Question 5: A structure weighing 2500 kN (excluding pile cap weight) is to be supported on a pile group (driven precast concrete piles). The soil profile is shown in figure 1. Design a pile foundation such that the maximum settlement of the group does not exceed 20 mm, and pile group is safe from shear failure of the soil. OCR for the clay till is 4 to 5 and OCR of clay shale is 6 to 8. Hint: Because of high OCR value, ignore the consolidation settlement of pile group, however, immediate settlement of the pile group would occur. Depth below ground 0 Soil profile Topsoil SM Silty sand 4(1.21 .8 (2.4) 2700 pst (129 kN/m.?) 12 18 Water Table 12 (3.6) 20 Clay til 16 (4.8) CL 10 18 Depth, ftin) 20 (6.0) - 2728 pst (131 kN/m2) 16 24 (7.2) 14 28 (8.4) 16 32 19.6) Clay shale 13152 psf (630 kN/m.) 12 36 (10.8) 12 40 (12.0) Figure 1 Soil profile (qu = unconfined compressive strength, w = natural moisture content)