We apply safety factors.
Potain MD 265 (typical for 6–10 story buildings) Max working load: 12 t at 15 m radius Max free-standing height: 45 m
$$e = \frac1,2001,457.5 = 0.823 \text m$$ $$e_limit = \frac5.56 = 0.917 \text m$$
Where Z = section modulus = (B * L²) / 6.
): The most critical factor. It is caused by the off-center weight of the jib/load and lateral wind forces acting at a high altitude. Load Conditions to Analyze
We use the max pressure calculated previously: $\approx 130 \text kN/m^2$.
within acceptable structural codes (like Eurocode 7 or ACI 318), calculate maximum soil pressure ( qmaxq sub m a x end-sub
qmax=2×21503×6.0×(6.02−1.71)=430018×1.29=430023.22=185.18 kPaq sub m a x end-sub equals the fraction with numerator 2 cross 2150 and denominator 3 cross 6.0 cross open paren 6.0 over 2 end-fraction minus 1.71 close paren end-fraction equals the fraction with numerator 4300 and denominator 18 cross 1.29 end-fraction equals 4300 over 23.22 end-fraction equals 185.18 kPa Result: OK. The soil can safely support the peak pressure. Step 5: Structural Concrete and Reinforcement Design
| | Description | Typical Application | | :--- | :--- | :--- | | Spread Footing (Isolated Block) | A large concrete pad that distributes crane loads directly to the soil. | Good soil conditions with high bearing capacity (e.g., dense sand or rock). | | Cruciform (Cross-Shaped) | A cross-shaped concrete base with long arms extending from the mast. | 400–600 kN·m class cranes; provides large overturning resistance with less concrete. | | Pile Foundation | Uses driven or cast-in-place piles (e.g., 4-pile square pattern) connected by a cap to reach deeper, stronger soil layers. | Poor soil conditions (soft clay, high water table) or heavy cranes >1000 kN·m. | | Combined Pile–Cap Foundation | Reinforced concrete cap bridging multiple piles; often used in deep basement excavations. | High-rise construction where soil near the surface is weak. |
We estimate the dimensions based on a rule of thumb: The foundation weight should be roughly 1.5 to 2 times the vertical load to provide stability.
In this article, we provide a detailed design calculation example for a typical tower crane foundation (pad footing + anchor bolts) and, crucially, direct you to authoritative, downloadable calculation links at the end.
The twisting force generated when the crane starts or stops rotating. Key Calculation Steps
, the shear span outside the critical section is small, and the concrete cross-section easily handles the structural shear force without stirrups.
We apply safety factors.
Potain MD 265 (typical for 6–10 story buildings) Max working load: 12 t at 15 m radius Max free-standing height: 45 m
$$e = \frac1,2001,457.5 = 0.823 \text m$$ $$e_limit = \frac5.56 = 0.917 \text m$$
Where Z = section modulus = (B * L²) / 6. tower crane foundation design calculation example link
): The most critical factor. It is caused by the off-center weight of the jib/load and lateral wind forces acting at a high altitude. Load Conditions to Analyze
We use the max pressure calculated previously: $\approx 130 \text kN/m^2$.
within acceptable structural codes (like Eurocode 7 or ACI 318), calculate maximum soil pressure ( qmaxq sub m a x end-sub We apply safety factors
qmax=2×21503×6.0×(6.02−1.71)=430018×1.29=430023.22=185.18 kPaq sub m a x end-sub equals the fraction with numerator 2 cross 2150 and denominator 3 cross 6.0 cross open paren 6.0 over 2 end-fraction minus 1.71 close paren end-fraction equals the fraction with numerator 4300 and denominator 18 cross 1.29 end-fraction equals 4300 over 23.22 end-fraction equals 185.18 kPa Result: OK. The soil can safely support the peak pressure. Step 5: Structural Concrete and Reinforcement Design
| | Description | Typical Application | | :--- | :--- | :--- | | Spread Footing (Isolated Block) | A large concrete pad that distributes crane loads directly to the soil. | Good soil conditions with high bearing capacity (e.g., dense sand or rock). | | Cruciform (Cross-Shaped) | A cross-shaped concrete base with long arms extending from the mast. | 400–600 kN·m class cranes; provides large overturning resistance with less concrete. | | Pile Foundation | Uses driven or cast-in-place piles (e.g., 4-pile square pattern) connected by a cap to reach deeper, stronger soil layers. | Poor soil conditions (soft clay, high water table) or heavy cranes >1000 kN·m. | | Combined Pile–Cap Foundation | Reinforced concrete cap bridging multiple piles; often used in deep basement excavations. | High-rise construction where soil near the surface is weak. |
We estimate the dimensions based on a rule of thumb: The foundation weight should be roughly 1.5 to 2 times the vertical load to provide stability. It is caused by the off-center weight of
In this article, we provide a detailed design calculation example for a typical tower crane foundation (pad footing + anchor bolts) and, crucially, direct you to authoritative, downloadable calculation links at the end.
The twisting force generated when the crane starts or stops rotating. Key Calculation Steps
, the shear span outside the critical section is small, and the concrete cross-section easily handles the structural shear force without stirrups.