Journal of Structural and Construction Engineering

Journal of Structural and Construction Engineering

Experimental and numerical Investigation on 3D strut & tie model of concrete pile caps

Document Type : Original Article

Authors
mojtaba ahmadi 1
Reza Morshed 2
1 Master of Structural Engineering,, Civil Engineering Department, Yazd University, Yazd,, ,Iran
2 Associate Professor, Civil Engineering Department, Yazd University, Yazd, Iran
10.22065/jsce.2023.397774.3120
Abstract
Pile caps are used to transfer forces from one or more columns to a group of piles. Despite their importance in the structure, most Codes do not have a certain design method that leads to a clear understanding of resistance and behaviour of these elements. Strut & Tie model was proposed by creating a correct understanding of this behaviour and improving the previous design provisions for discontinuity regions. In the new edition of the American Building Code, ACI 318-19, the confinement effect is taken into account in calculation of compressive strength; so designing with the S&T method in three-dimensional model turn outs to be more economical and effective. In this research, 2 samples of Pile caps were tested in laboratory. The first sample had a concentrated rebar arrangement and the second sample had a uniform rebar arrangement. Both samples had 4 rows of rebar in each direction. The first sample was analyzed by ACI 318-19 S&T method. Also the behaviour of both Samples were evaluated by the finite element method. The loading capacity obtained from the S&T model was lower and more conservative than the other two methods. All piles had failed in shear mode and the failure had started from the bottom node on the bearing support. The Sample with uniform arrangement of rebar showed more load and displacement capacity than the sample with concentrated rebar arrangement.
Keywords
Pile cap
Strut &
tie method
Shear strength
Experimental Investigation
Reinforced concrete

Subjects

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  • Receive Date 10 June 2023
  • Revise Date 17 November 2023
  • Accept Date 27 November 2023