A Simple, Closed-Form Method for Determining the Superelevation of Tall Reinforced Concrete Buildings

The vertical shortening of tall buildings is not negligible, and it is important to account for these deformations to minimize differential movement and ensure that the finished building is level. Compensation via superelevation is common in reinforced concrete construction, but traditional methods of calculating these corrections require stepwise analysis accounting for construction sequence nonlinearity. In this paper, the shortening subsequent to storey construction is derived based upon the elastic displacement profile of the full structure. It is shown that the shortening prior to storey construction may be approximated as a parabola. Long-term volumetric effects may also be included using a strain multiplier approach. The simplified formulation is validated by comparison with detailed construction sequence finite element analyses for a sample column and a case-study wall, showing excellent agreement at a fraction of the computational cost. The proposed method therefore gives practicing engineers a conceptually simple but theoretically sound way to account for vertical shortening in tall reinforced concrete buildings.