Designing a tower crane foundation requires rigorous structural checks to ensure it can withstand the extreme overturning moments and vertical loads of a freestanding crane. Most foundations are designed as isolated footings (spread footings), though pile caps are used if soil bearing capacity is low. Step-by-Step Calculation Example
A standard calculation procedure typically follows these steps: tower crane foundation design calculation example link
Tower Crane Footing Structural Design For All Cranes PDF - Scribd Concrete: Grade C30/37 (Density = $25 \text kN/m^3$)
Figure 1: Stability against over turning. assume h=1.50m ==> over turning moment MOT = 4908+91*1.5 = 5044.5 KN. m footing weight = Tower Crane Foundation Design Details | PDF - Scribd C. Material Properties
The concrete foundation itself must be designed to resist bending moments and shear forces. The crane mast exerts a massive upward pull on the anchor bolts on one side and a downward push on the other.
Sliding resistance:
( R_slide = (V_d) \times \tan(2/3 \phi') + c' \cdot A_base )
( V_d ) (ULS, with wind) = ( 1.35 \times 950 + 1.0 \times 1134 = 2,416 , kN )
( \tan(2/3 \times 30°) = \tan(20°) = 0.364 )
Friction term = ( 2416 \times 0.364 = 879 , kN )
Cohesion term = ( 5 \times 30.25 = 151 , kN )
Total resistance = ( 879 + 151 = 1,030 , kN )
Driving force ( H_d = 1.5 \times 75 = 112.5 , kN )
( FOS_slide = 1030 / 112.5 = 9.2 \gg 1.5 ) → OK.