Tower Crane Loads on Foundation 2

[EricHimawan]

Dear all,

I am trying to design a tower crane foundation, standing on a pile cap. The manufacturer's brochure told me the necessary loads for foundation, namely the compression (around 2000 kN) and uplift (around 1600 kN) loads, which I would apply on opposite corners of where the TC mast would stand, positions of the loads would be rotated along with load combinations.

The problem is, the Tower Crane's free standing height is around 40 meter, while our building would reach 100 meter + height, which would need the usage of tie-ins to the building. But what about the foundation load? We have 2 competing views in this matter:
1. That the additional mast heights should be added to the foundation loads
2. That the tie-ins would help distribute the loads and therefore we can use the values stated in the brochure, no addition.

It is to be noted that the same brochure stated the free-standing weight is around 1000 kN, and even with all the extra mast height it still haven't reached the value of Compression Load stated.

What do you think? Do you have any references regarding foundation loads for TC that surpasses free-standing weight? Thank you.

 

[Agent666]

Usually the tie in would be for lateral loads only. Once you're past the manufacturers configuration it would pay to discuss the configuration with the manufacturer. Their engineering department might need to be involved. But I'd find it hard to get past needing to take the full 3 lifts at foundation level.

On the plus side once you're at a height where you are tied in, then potentially any overturning at foundation level is lower than for the cantilevered mast.

The info they give you is foundation loads only, and even then typically the loads don't usually match the load combinations that might be required by your local crane design codes. They don't give you anything on the superstructure and whether you can achieve the configuration you're after stacked 3 times higher.

 

[hokie66]

What Agent666 said.