Title:
Punching Shear Strength of Isolated Concrete Column Footings with Low Shear Span-Depth Ratios
Author(s):
Ngoc Hieu Dinh, Juok Noh, Kyoung-Kyu Choi, and Hong-Gun Park
Publication:
Structural Journal
Volume:
121
Issue:
3
Appears on pages(s):
25-41
Keywords:
analytical model; design codes; punching shear; reinforced concrete (RC) footings; soil-bearing stiffness
DOI:
10.14359/51740457
Date:
5/1/2024
Abstract:
In the present research, an experimental study was performed to
investigate the punching shear strength of isolated concrete column
footings having low shear span-depth ratios (a/d). The primary
test parameters included the a/d, concrete compressive strength,
and soil-bearing stiffness. Twelve column footings were tested for
a/d ranging from 1.0 to 2.5. A support system using rubber-wood
composite blocks was designed to simulate the equivalent soilbearing stiffness. The test results showed that as the a/d decreased, the punching shear strength of the footings significantly increased with a change in the angle of the punching failure surface.
Contrarily, the soil-bearing stiffness did not significantly affect
the punching shear strength, although it did affect the stiffness and
deflection of the footings, as well as the contact pressure distribution
beneath the footings. Furthermore, to evaluate the punching
shear strength of footings with low a/d, an analytical model was
proposed based on the web-shear cracking mechanism.