Footing result
This is a sample calculation. Enter your own footing to run a real check.
Run your own footing
Wall footing
B 48 × h 12 in
qa 3 ksf
f′c 3,000 psi
fy 60 ksi
#4 bottom bars
d 8.75 in
PASS
All checks pass: bearing, flexure, shear, development length, wall interface.
Soil bearing, overturning and sliding
PASS
D/C bearing (q max / q net)
0.46
- qmax (maximum service pressure)
- 1.25 ksf
- qnet (net allowable pressure)
- 2.67 ksf
| Quantity | Value |
|---|---|
| qmax (maximum pressure, ksf) | 1.25 |
| qmin (minimum pressure, ksf) | 1.25 |
| qnet (qa less overburden and self-weight, ksf) | 2.67 |
| e (eccentricity, in) | 0.00 |
| B/6 (kern limit, in) | 8.00 |
| Footing self-weight (kip/ft) | 0.60 |
| Soil weight above footing (kip/ft) | 0.72 |
| Fresist (friction resistance, kip/ft) | 2.50 |
| FSot (overturning factor of safety, minimum 1.5) | N/A (no overturning moment) |
| FSslide (sliding factor of safety, minimum 1.5) | N/A (no lateral force) |
| Bearing (qmax ≤ qnet) | Satisfied |
| Kern (e ≤ B/6, full contact) | Within kern |
| Overturning (FS ≥ 1.5) | Satisfied |
| Sliding (FS ≥ 1.5) | Satisfied |
Service loads; friction-only sliding resistance
ACI 318-19 §13.2.1 · §13.2.2
Flexure
PASSTransverse bars (per 1-ft strip)
D/C moment
0.13
- φMn (design moment capacity)
- 15.04 kip-ft/ft
- Mu (factored moment at column face)
- 1.97 kip-ft/ft
| Quantity | Value |
|---|---|
| b (design width, in) | 12.0 |
| d (effective depth, in) | 8.75 |
| As,req (steel required for Mu, in²) | 0.05 |
| As,min (minimum steel, in², §13.3.3.2) | 0.26 |
| Bars (number of #4 bars per ft strip) | 2 |
| As,prov (steel provided, in²) | 0.40 |
| s (center-to-center spacing, in) | 5.50 |
| Clear spacing (in, minimum max(db, 1 in), §25.2.1) | 5.00 |
| a (stress block depth, in) | 0.78 |
| φMn (design moment strength, kip-ft/ft) | 15.04 |
| Status | PASS |
φ = 0.90; critical section at the wall face
ACI 318-19 §13.2.7.1 · Table 21.2.2 · §25.2.1
One-way shear
PASSTransverse (per 1-ft strip)
D/C shear
0.25
- φVc (design shear capacity)
- 5.39 kip/ft
- Vu (factored shear at d from the face)
- 1.35 kip/ft
| Quantity | Value |
|---|---|
| ρw (As,prov / (bw·d)) | 0.0038 |
| Vc (concrete shear strength, kip/ft) | 7.19 |
| φVc (design shear strength, kip/ft) | 5.39 |
| Vu (factored shear, kip/ft) | 1.35 |
| Status | PASS |
φ = 0.75; no shear reinforcement
ACI 318-19 §13.2.7.2 · Table 22.5.5.1
Development length
PASSTransverse bars
D/C development length
0.80
| Quantity | Value |
|---|---|
| ld (development length, in) | 13.1 |
| ld adjusted (reduced for excess steel, minimum 12 in, in) | 12.0 |
| lavail (available length beyond the critical section, in) | 15.0 |
| cb (cover or half spacing term, in) | 2.75 |
| ψt (casting position) | 1.00 |
| ψe (coating) | 1.00 |
| ψs (bar size) | 0.80 |
| ψg (grade) | 1.00 |
| Status | PASS |
Straight bars in tension, no hooks
ACI 318-19 §13.2.7.1 · Eq. 25.4.2.4a · Table 25.4.2.5
Wall to footing interface
PASS
D/C bearing on concrete
0.01
- φBn (design bearing strength)
- 413.41 kip/ft
- Pu (factored load)
- 7.00 kip/ft
| Quantity | Value |
|---|---|
| A1 (loaded area, in²) | 144 |
| A2 (supporting area (frustum base), in²) | 432 |
| φBn (design bearing strength, kip/ft, §22.8.3.2) | 413.41 |
| As,dowel,min (minimum dowel area, in²/ft) | 0.17 |
Feasible dowel sizes
Sizes whose compression development length fits in the footing depth. A design aid; detailing is the engineer’s responsibility.
No dowel size from #4 to #8 develops in the available depth. Increase the footing thickness.
φ = 0.65 for bearing
ACI 318-19 §22.8.3.2 · §16.3.4.1 · §25.4.9.2
Warnings
No dowel size #4 to #8 develops in 8.5 in available depth (25.4.9.2); increase footing thickness