Title:
Strut-and-Tie Model Analysis for Strength Prediction of Deep Beams
Author(s):
Jung-woong Park and Daniel Kuchma
Publication:
Structural Journal
Volume:
104
Issue:
6
Appears on pages(s):
657-666
Keywords:
deep beams; failure strength; shear strength; strut-and-tie model
DOI:
10.14359/18947
Date:
11/1/2007
Abstract:
In this paper, a strut-and-tie-based method is presented for calculating the strength of reinforced concrete deep beams. The proposed method employs constitutive laws for cracked reinforced concrete, considers strain compatibility, and uses a secant stiffness formulation. This method accounts for the failure modes due to crushing of the nodal compression zone at the top of the diagonal strut, yielding of the longitudinal reinforcement, as well as that of strut crushing or splitting. This method is used to calculate the capacity of 214 normal- and high-strength concrete deep beams that have been tested in laboratories. This method is illustrated to provide more accurate estimates of capacity than the strut-and-tie provisions in either ACI 318-05 or the Canadian code. The comparison shows that the proposed method consistently predicts the strengths of deep beams with a wide range of horizontal and vertical web reinforcement ratios, concrete strengths, and shear span-to-depth ratios (a/d) well. The proposed approach provides valuable insight into the design and behavior of deep beams.