Tower Crane Foundation Design Calculation Example Link [repack] Page
Tower Crane Foundation Design: Calculations and Examples Designing a tower crane foundation is a critical temporary works task that ensures the stability of the crane under maximum reactions and moments. The foundation must be designed as a freestanding structure to ensure it independently resists all vertical loads, horizontal shears, and overturning moments. Common Foundation Types
- American Society of Civil Engineers (ASCE) - www.asce.org
- International Organization for Standardization (ISO) - www.iso.org
- Construction Industry Institute (CII) - [www.construction institute.org](http://www.construction institute.org)
Check: e > B/6 = 5.0/6 = 0.833 m → partial uplift occurs.
Max bearing pressure under trapezoidal distribution: tower crane foundation design calculation example link
Final trial: thickness = 1.5 m, L×B = 5.5×5.5 m
Self-weight = ( 5.5^2 \times 1.5 \times 25 = 1,134 , kN )
( V_d = 1.35(950 + 1134) = 2,813 , kN )
[
\sigma_max = \frac281330.25 + \frac6 \times 39005.5 \times 30.25 = 93.0 + 140.8 = 233.8 , kPa
]
Still high → the soil is too weak. Conclusion: Either use piles or improve bearing capacity to ~250 kPa. American Society of Civil Engineers (ASCE) - www
For eccentric loading where $e < B/6$: The pressure distribution is trapezoidal. Check: e > B/6 = 5
The Design Philosophy: The primary objective is to ensure stability against Overturning (OT), Sliding (Shear), and Bearing Capacity failure. The foundation must be heavy enough and large enough so that the crane does not tip over, even in the worst-case wind loading scenario.
- Width ($B$): 18.0 ft
- Depth ($D$): 5.0 ft
- Pedestal: (Often ignored in simplified preliminary calcs, but here we assume the footing is a pure block).
Comparison: $$2.06 \text ksf < 3.0 \text ksf (SBC)$$ Pass. The soil can safely support this foundation.
A standard calculation procedure typically follows these steps: