The plan of a group pile is shown in Figure P12.34. Assume that the piles are embedded in a saturated homogeneous clay having a c_u = 90 kN/m². Given: diameter of piles (D) = 316 mm, center-to-center spacing of piles = 600 mm, and length of piles = 20 m. Find the allowable load carrying capacity of the pile group. Use Table 12.11 and FS = 3.

Figure P12.34.

Table 12.11

Table 12.11

Variation of a (Interpolated

Values Based on

Terzaghi et al., 1996)

c_u/p_a ……………………………. α

≤ 0.1 ………………………….. 1.00

0.2 ………………………….. 0.92

0.3 ………………………….. 0.82

0.4 ………………………….. 0.74

0.6 ………………………….. 0.62

0.8 ………………………….. 0.54

1.0 ………………………….. 0.48

1.2 ………………………….. 0.42

1.4 ………………………….. 0.40

1.6 ………………………….. 0.38

1.8 ………………………….. 0.36

2.0 ………………………….. 0.35

2.4 ………………………….. 0.34

2.8 ………………………….. 0.34

Note: p_a = atmospheric pressure ≈ 100 kN/m²

Transcribed Image Text:

k-d -d- 1.