GGU-SLAB: Analysis of the torsional stiffness for circular footings

The GGU-FOOTING program calculates the differential settlement s of the two characteristic points of the circular footing. The settlement calculations are carried out according to DIN 4019 with limiting depth calculation. The distance L between the two characteristic points for a circular footing with the diameter D is

L = 0,845 · D

This allows the torsion j of the footing to be calculated.

With the moment M, the differential setting Ds has been determined. This gives the torsional stiffness k_j of the entire system.

The equation contained in many data sheets of wind turbine manufacturers

assumes an infinitely extended, elastic-isotropic half-space and is therefore not applicable for stratified systems. The equation thus assumes an unrealistically large limiting depth for the settlement calculation. Therefore, the settlements are overestimated.

For the torsional stiffness to be calculated in GGU-FOOTING using the above-mentioned equation of the wind turbine manufacturers, simulate an infinitely large limiting depth by entering a very large, fixed limiting depth.