Title:
Evaluation of Column Load for Generally Uniform Grid Reinforced Pile Cap Failing in Punching
Author(s):
Honglei Guo
Publication:
Structural Journal
Volume:
112
Issue:
2
Appears on pages(s):
123-134
Keywords:
building code; pile cap; punching shear resistance; strut-and-tie model (STM).
DOI:
10.14359/51687420
Date:
3/1/2015
Abstract:
Currently, the punching shear resistance of pile caps is frequently evaluated empirically, and although the strut-and-tie model (STM) may be used to calculate the issue, the two weaknesses of STM—conservative nature and difficult configuration—hinder its rational solution. To attempt to solve these issues, this paper presents a generalized method of spatial STMs to evaluate punching shear resistance of general pile caps with uniform grid reinforcement (TPM). Based on results of the spatial strut-and-tie bearing mechanism of pile cap punching failure, three-dimensional (3-D) rather than two-dimensional (2-D) strut strength is derived. During this
process, nonlinear finite element analysis in conjunction with the derivation of a gradual least-square method for multiple variables is adopted. TPM is verified by 98 specimens in the literature, whose parameters (reinforcement ratio of tension tie, punching-span ratio, concrete strength, pile number, and pile arrangement) vary, respectively; the comparisons with the other four methods are made. It is indicated that TPM is extensively applicable to the evaluation of the punching shear resistance of general pile caps with uniform grid reinforcement.