Title: Torque Capacity of U- and H-Shaped Reinforced Concrete Walls using Warping-Equivalent Bending Moment

Author(s): Ryan D Hoult and João Pacheco de Almeida

Publication: Structural Journal

Volume:

Issue:

Appears on pages(s):

Keywords: core, design, high-rise, seismic, torque, twist, ultimate, walls

DOI: 10.14359/51740574

Date: 2/14/2024

Abstract:
Non-planar reinforced concrete core walls form the backbone of millions of mid- and high-rise buildings, resisting both gravity and lateral loads from wind and earthquakes. The latter inevitably induce torsional demands, even in the case of full plan-wise-symmetric structures, which add to bending, shear, and axial deformations. Unfortunately, current international building codes are not applicable to the design of non-planar sections governed by warping torsion rather than circulatory torsion. This lack of information and guidance in building codes has resulted in a very limited number of structures being designed to account for warping stresses, even though the latter can be of a similar order of magnitude to bending stresses and, therefore, of major significance. A simple procedure is herein presented to estimate the ultimate warping moment and ultimate torque of non-planar RC sections based on “warping-equivalent” ultimate bending moments from sectional analysis. A circular and bilinear bending moment-torque interaction relationship is proposed and compared to the existing albeit limited experimental and numerical results available in the literature.