Title:
Simplification of Softened Strut-and-Tie Model for Strength Prediction of Discontinuity Regions
Author(s):
Shyh-Jiann Hwang, Ren-Jie Tsai, Weng-Kin Lam, and Jack P. Moehle
Publication:
Structural Journal
Volume:
114
Issue:
5
Appears on pages(s):
1239-1247
Keywords:
compressive softening effect; diagonal compression; discontinuity region; reinforced concrete; shear; strength; strut-and-tie
DOI:
10.14359/51689787
Date:
9/1/2017
Abstract:
A geometric discontinuity caused by abrupt changes in cross-sectional dimensions and a force discontinuity caused by concentrated loads results in discontinuity regions due to the disturbance in the flow of internal forces. A softened strut-and-tie model has been developed for determining the shear strength of discontinuity regions that fail under diagonal compression. The softened strut-and-tie model requires complicated computations, consequently making it challenging to apply in engineering practice. In this paper, a further simplification of the softened strut-and-tie model is proposed to facilitate design practice. Strength predictions of the simplified model correlate well with 449 test results of deep beams, corbels, squat walls, and beam-column joints available from the
literature. The simplified model incorporates the shear-resisting mechanisms as postulated by the softened strut-and-tie model, and it is a function of the concrete compressive strength, steel yield strength, shear reinforcement ratio, and geometric configuration of the discontinuity region.