Hugo Esquivel
Guang Lin

This article aims to amend the traditional formulas for polar moment of inertia suggested in Section R۸.۴.۴.۲.۳ of ACI ۳۱۸-۱۹ and other sources. The authors claim that these formulas have been incorrectly derived as far back as ۱۹۶۰s due to an incorrect implementation of Steiner’s theorem (parallel axis theorem) for sections spanning in three-dimensional space. To support the claim, a formal proof using elementary calculus is presented in order to obtain the correct formulas with mathematical rigor. Then, the implications of using the traditional formulas versus the correct ones are investigated with the solution of a design problem related to a combined footing. Doi: ۱۰.۲۸۹۹۱/CEJ-۲۰۲۳-۰۹-۱۱-۰۱۵ Full Text: PDF

ACI ۳۱۸-۱۹; Jc Method; Slab-Column Connections; Structural Design; Two-Way Shear Action.