Title: Behavior of Reinforced Concrete Horizontally Curved Beams
Author(s): Thomas T.C. Hsu, Mehmet Inan, Leonard Fonticiella
Publication: Journal Proceedings
Appears on pages(s): 112-123
Keywords: beams (supports); cracking (fracturing); curved beams; deformation; elastic analysis; failure mechanisms; flexural strength; guideways; loads (forces); rapid transit railways; reinforced concrete; statistically indeterminate structures.
Seven reinforced concrete horizontally curved beams have been tested. Each beam had a cross section of 6 x 12 in. (15.24 x 30.48 cm), a radius of 9 ft (2.74m), and a subtending angle of 90 deg. Each beam was designed to be fixed at both ends and subjected to a concentrated load at midspan. These tests showed that significant redistribution of torsional and bending moments was observed after cracking. Therefore, the conventional design based on "Building Code Requirements for Reinforced Concrete (ACI 318-71)" and the elastic analysis assuming an uncracked section may cause premature yielding or failure at the supports. It is suggested that elastic analysis of moments should be based on cracked sections. The post-cracking torsional sttiffness of curved beams can be reasonably predicted by a theoretical equation derived by the first author.