Pile Spacing Requirements

Per CRSI 13-16, for d_p≤ 12",

Minimum c/c Pile Spacing,

L = \max {\begin{matrix} 3'-0" \\ 3 \times Pile Diameter = 2'-0" \\ Clear Between Piles = 2'-8" \end{matrix} = 3'-0"

Per CRSI 13-18, for P ≤ 60 tons,

Minimum Distance Pile Cap Edge to Center of Piles, E = 1'-3"

Individual Pile Capacity Check

We must make an assumption regarding the pile cap depth before proceeding. We will use an estimated total depth, D = d + d_c = 57"

Total service load supported at underside of pile cap,

P_{service} = P_{service} + Pile Cap Weight

= 625 + [\frac{57 (138) (102)}{12^{3}}] (\frac{150}{1, 000}) = 695 kips

P'_u = 1.6 (695) = 1,111 kips

Load supported by single pile,

P_{p} = (\frac{695}{12}) = 57.9 kips (service)

Also, for these assumptions, d = 57 - 6 - 3 1.128 - 0.5(1.128) = 46.3" (47.4")

P_{p} = \frac{{P^{'}}_{u}}{n} \pm \frac{M_{u \min} x_{p}}{\sum_{1}^{n} x_{p}^{2}} \pm \frac{M_{u maj} y_{p}}{\sum_{1}^{n} y_{p}^{2}}

where

n	=	Total number of piles in group
x_p, y_p	=	x, y coordinates of pile under consideration
(I_pg)_x	=	2 x 4 x 362 = 10,368 in²
(I_pg)_y	=	(36/2)2 x 6 + (1.5 x 36)2 x 6 = 19,440 in²