1. The plan of a group pile is shown in Figure P 9.27. Assume that the piles are embedded in a saturated homogeneous clay having a cu 5 90 kN/m2. Given: diameter of piles (D) 5 316 mm, center-to-center spacing of piles 5 600 mm, and length of piles 5 20 m. Find the allowable load-carrying capacity of the pile group. Use Table 9.10 and FS 5 3.

2. Redo Problem 9.27 with the following: center-to-center spacing of piles 5 30 in., length of piles 5 45 ft,D 5 12 in., cu 5 860 lb/ft2, and FS 5 3. Use Table 9.10.

3. The section of a 4 3 4 group pile in a layered saturated clay is shown in Figure P 9.29. The piles are square in  cross  section  (356  mm  3 356 mm). The center-to-center spacing (d) of the piles is 1 m. Determine the allowable load- bearing capacity of the pile group. Use FS 5 3 and Table 9.10.