Pi, F.; Ren, W.; Yang, X., and Liu, G., 2020. A simplified method to calculate the additional interstory drift of high-rise steel frame based on the P-Δ effect. In: Gong, D.; Zhang, M., and Liu, R. (eds.), Advances in Coastal Research: Engineering, Industry, Economy, and Sustainable Development. Journal of Coastal Research, Special Issue No. 106, pp. 618–623. Coconut Creek (Florida), ISSN 0749-0208.

The additional interstory drift of high-rise steel frame structure caused by the P-Δ effect usually consists of additional shear interstory drift and additional overall bending interstory drift. For the lateral displacement calculation of structures, the influence of the additional interstory drift is ignored in the first order, and the additional overall bending interstory drift is not considered in the second order. To study the influence of additional deformation on the high-rise steel frame structure, the elastic, simplified formula of additional overall bending interstory drift caused by P-Δ effect is deduced. Then, the simplified calculation method of additional interstory drift is proposed. The numerical simulation using the finite-element and the simplified method of a two-span, 18-story steel frame under horizontal, uniform load is conducted. The results of the two methods are in good agreement, which proves that the simplified method is feasible. In addition, the additional overall bending interstory drift and its proportion in additional interstory drift are analyzed when the aspect ratio of structure is different. The results show that the proportion increases with an increasing aspect ratio and the story numbers; the proportion at the top story is all greater than 70%. Therefore, the additional overall bending interstory drift should be considered in the second-order lateral-displacement calculation.