Title: ACI Shear and Torsion Provisions for Prestressed Hollow
Author(s): Thomas T. C. Hsu
Publication: Structural Journal
Appears on pages(s): 787-799
Keywords: code provisions; concrete structures; design; guideways; hol-low
sections; prestressed concrete; reinforced concrete; shear; torsion.
New torsion design provisions have been proposed for the 1995 ACI Build-ing Code. As compared to the I989 provisions, these generalized I995 pro-visions have three advantages: First, they are applicable to closed cross sections of arbitrary shapes. Second, they are applicable to prestressed concrete. Third, they are considerably simplified by deleting the torsional concrete contribution and its interaction with shear: These new provisions are suitable for application to concrete guideways and bridges, because these large structures are always prestressed and are often chosen to have hollow box sections of various shapes. This paper discusses the back-ground of the new code provisions, suggests modifications to code formulas, and illustrates the application of the code provisions to prestressed hollow girders by way of a guideway example.