The following tables show the measurements of the minimum foundations for anchoring columns and posts, calculated according to the Sultzberger formula for K=5, K=10 and K=15 kg/cm3, as the soil volume compressibility coefficient, depending on if the soil is soft, normal or rocky, respectively.
Balance is considered stable if the equation is verified:
Being:
1,5 Mv = (M1 + M2)
Where:
Mv = F(H + 2/3 h)
M1 = 0,278 a h3K
M2 = P x 0,4a
Where:
F = horizontal stress on top (Tn)
H = height (m)
h = depth of foundations (m)
a = horizontal measurements of foundations (m)
P = weight of foundations and luminaire (Tn)
The horizontal stress at top is caused by the action of the wind on the column and its luminaire.
CURVED POSTS / VALUES OBTAINED
| H (m) | ROCKY K=15 a (cm) | ROCKY K=15 h (cm) | NORMAL K=10 a (cm) | NORMAL K=10 h (cm) | SOFT K=5 a (cm) | SOFT K=5 h (cm) |
|---|---|---|---|---|---|---|
| 4×1 | 40 | 60 | 50 | 65 | 50 | 75 |
| 5×1 | 45 | 60 | 50 | 65 | 50 | 80 |
| 6×1 | 45 | 65 | 50 | 70 | 50 | 80 |
| 6×1,5 | 45 | 65 | 50 | 70 | 50 | 85 |
| 7×1 | 45 | 65 | 50 | 70 | 50 | 85 |
| 7×1,5 | 45 | 70 | 50 | 75 | 50 | 90 |
| 8×1 | 45 | 70 | 50 | 75 | 50 | 90 |
| 8×1,5 | 45 | 70 | 50 | 75 | 50 | 95 |
| 9×1 | 40 | 75 | 50 | 80 | 50 | 95 |
| 9×1,5 | 45 | 75 | 50 | 80 | 55 | 95 |
| 9×2 | 45 | 75 | 50 | 80 | 55 | 95 |
| 10×1 | 45 | 75 | 50 | 85 | 55 | 95 |
| 10×1,5 | 45 | 80 | 50 | 85 | 55 | 100 |
| 10×2 | 45 | 80 | 50 | 85 | 55 | 105 |
| 12×1 | 60 | 90 | 65 | 100 | 70 | 120 |
| 12×1,5 | 60 | 90 | 65 | 100 | 75 | 120 |
| 12×2 | 65 | 100 | 70 | 110 | 80 | 125 |
| 12×2,5 | 65 | 102 | 75 | 115 | 80 | 125 |
COLUMNS / VALUES OBTAINED
| H (m) | Ø (m) | ROCKY K=15 a (cm) | ROCKY K=15 h (cm) | NORMAL K=10 a (cm) | NORMAL K=10 h (cm) | SOFT K=5 a (cm) | SOFT K=5 h (cm) |
|---|---|---|---|---|---|---|---|
| 4 | 76 | 45 | 60 | 50 | 65 | 55 | 77 |
| 5 | 60 | 45 | 60 | 50 | 65 | 55 | 77 |
| 5 | 76 | 45 | 65 | 50 | 70 | 55 | 80 |
| 6 | 50 | 45 | 60 | 50 | 65 | 55 | 77 |
| 6 | 60 | 45 | 65 | 50 | 70 | 55 | 80 |
| 6 | 76 | 45 | 70 | 55 | 70 | 60 | 85 |
| 7 | 50 | 45 | 65 | 50 | 70 | 55 | 80 |
| 7 | 60 | 45 | 70 | 55 | 70 | 60 | 85 |
| 7 | 76 | 45 | 75 | 55 | 75 | 60 | 90 |
| 8 | 50 | 45 | 70 | 55 | 70 | 60 | 85 |
| 8 | 60 | 45 | 70 | 55 | 75 | 60 | 90 |
| 8 | 76 | 50 | 75 | 55 | 75 | 60 | 90 |
| 8 | 88 | 50 | 75 | 55 | 80 | 60 | 95 |
| 8 | 102 | 50 | 85 | 55 | 95 | 60 | 110 |
| 8 | 124 | 50 | 90 | 55 | 100 | 60 | 120 |
| 9 | 50 | 50 | 70 | 55 | 75 | 60 | 90 |
| 9 | 60 | 50 | 75 | 55 | 75 | 60 | 90 |
| 9 | 76 | 50 | 75 | 55 | 80 | 60 | 95 |
| 9 | 88 | 50 | 85 | 55 | 95 | 60 | 110 |
| 9 | 102 | 50 | 90 | 55 | 100 | 60 | 115 |
| 10 | 50 | 50 | 70 | 55 | 75 | 60 | 90 |
| 10 | 60 | 50 | 75 | 55 | 80 | 60 | 95 |
| 10 | 76 | 50 | 75 | 55 | 95 | 60 | 110 |
| 10 | 88 | 50 | 90 | 55 | 100 | 60 | 115 |
| 10 | 102 | 50 | 95 | 55 | 105 | 60 | 120 |
| 12 | 60 | 50 | 90 | 55 | 100 | 60 | 115 |
| 12 | 76 | 50 | 95 | 55 | 105 | 60 | 120 |
| 14 | 76 | 65 | 105 | 70 | 120 | 75 | 125 |