Unified solutions on axial bearing capacity of round-ended concrete-filled steel tube short columns with binding bars

The currently formulae with many coefficients are too complicated to calculate the bearing capacity of concrete-filled steel tube (CFST) short columns. In this paper, an optimal calculation method was proposed for calculating the eccentric bearing capacity of CFST short columns by means of mechanical derivation. Additionally, the calculating results are compared with experimental data. It is shown that the optimal calculating formulae are highly accurate and easily applicable in engineering design.

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Nonlinear Finite Element Analysis of Stiffened T-Shaped Thin-Walled Concrete-Filled Steel Tube Composite Columns

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.193-194.1461 ◽

2012 ◽

Vol 193-194 ◽

pp. 1461-1464

Author(s):

Bai Shou Li ◽

Ai Hua Jin

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Bearing Capacity ◽

Steel Tube ◽

Ultimate Bearing Capacity ◽

Element Analysis ◽

Concrete Filled Steel Tube ◽

Composite Columns ◽

Short Columns ◽

Thin Walled

Based on the characteristics of the special-shaped concrete-filled steel tubes and consideration of material nonlinearity of constitutive relation, stimulation of 6 T-shaped thin-walled ribbed and un-ribbed concrete-filled steel tube short columns is implemented, as well as comparable analysis of stress, strain, displacement and bearing capacity, through the finite element analysis software ANSYS. The result indicates that the rib can effectively improve the ductility, delaying the buckling occurs, which enhances the core concrete confinement effect, so as the stimulated ultimate bearing capacity which is greater than nominal ultimate bearing capacity.

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Experimental Verification on Bearing Capacity of Concrete-Filled Steel Tube Short Columns Based on Unified Theory

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.163-167.1999 ◽

2010 ◽

Vol 163-167 ◽

pp. 1999-2004 ◽

Cited By ~ 4

Author(s):

Jing Ji ◽

Wen Fu Zhang ◽

Hai Yan Sui

Keyword(s):

Mechanical Properties ◽

Bearing Capacity ◽

Axial Force ◽

Calculation Method ◽

Steel Tube ◽

Ultimate Bearing Capacity ◽

Unified Theory ◽

Concrete Filled Steel Tube ◽

Short Columns ◽

Load Displacement

To verify the rationality of calculation method on unified theory of concrete - filled steel tube short columns under axial force, Experimental Study on mechanical properties of the 12 concrete -filled steel tube short columns with 7 different sections under axial force is preformed. Failure process and Failure mode of them are observed, load-displacement curves are obtained, and the influence for confinement coefficient ξ to the mechanical properties of short columns under axial load is analyzed. Based on load-displacement curves, ultimate bearing capacities of them are given. By comparison for ultimate bearing capacity obtained by testing and the bearing capacity according to unified theory, the results show both are in good agreement. Calculation method on unified theory of concrete - filled steel tube is fit for calculating ultimate bearing capacity of short columns under axial force with different sections, and the results are safe and reliable.

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Unified solutions on axial bearing capacity of T-shaped concrete-filled steel tube short columns with binding bars

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/636/1/012024 ◽

2021 ◽

Vol 636 ◽

pp. 012024

Author(s):

Qingyun Ge ◽

Fulian Yang ◽

Wenxiu Dong ◽

Zhu Bian

Keyword(s):

Bearing Capacity ◽

Steel Tube ◽

Concrete Filled Steel Tube ◽

Short Columns

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Bearing capacity of composite shear wall incorporating a concrete-filled steel tube boundary and column-type reinforced wall

Advances in Structural Engineering ◽

10.1177/1369433220911156 ◽

2020 ◽

Vol 23 (10) ◽

pp. 2188-2203

Author(s):

Zhao Nannan ◽

Wang Yaohong ◽

Han qing ◽

Su Hao

Keyword(s):

Bearing Capacity ◽

Residual Deformation ◽

Shear Walls ◽

Shear Wall ◽

Steel Tube ◽

Concrete Filled Steel Tube ◽

Composite Shear Wall ◽

Boundary Shear ◽

Column Type ◽

Composite Shear

Composite shear walls are widely used in high-rise buildings because of their high bearing capacity. To improve the bearing capacity of ordinary shear walls, restraining elements are usually installed at both boundaries or within the wall body. In this article, two different restraining elements, namely, a rectangular steel tube and a column-type reinforcement (the whole wall body was restrained by segmented stirrups and tied by diagonal bars), were applied to the boundary frame and wall body of the shear wall either jointly or separately. A new type of steel-concrete composite shear wall, referred to as a composite shear wall incorporating a concrete-filled steel tube boundary and column-type reinforced wall, was proposed. In addition, three specimens with different restraining elements, namely, a column-type reinforced shear wall, a concrete-filled steel tube boundary shear wall and an ordinary reinforced concrete shear wall, were presented for comparison. The influences of the two different restraining elements on the seismic performance and bearing capacity of the shear walls were analyzed from four perspectives of failure mode, hysteresis behavior, stiffness and residual deformation, and the equivalent lateral pressures of the two restraining elements were calculated. Based on the plane-section assumption, expressions for the crack, yield, peak and ultimate bearing capacities were derived, and the effects of the two restraining elements on the peak and ultimate bearing capacities were considered. The results show that these two restraining elements significantly improved the bearing capacity of the shear wall specimens, and the concrete-filled steel tube restraining element was more effective than the column-type reinforced restraining element. Finally, the calculated values of the bearing capacity of the four different restraining elements of the shear wall specimens proposed in this article were in good agreement with the experimental values.

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Study of the Ultimate Bearing Capacity of Concrete-filled Steel Tube K-Joints

KSCE Journal of Civil Engineering ◽

10.1007/s12205-019-1268-7 ◽

2019 ◽

Vol 23 (5) ◽

pp. 2254-2262 ◽

Cited By ~ 5

Author(s):

Kaizhong Xie ◽

Hongwei Wang ◽

Jinhao Pang ◽

Jianxi Zhou

Keyword(s):

Bearing Capacity ◽

Steel Tube ◽

Ultimate Bearing Capacity ◽

Concrete Filled Steel Tube

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Axial behaviour of slender concrete-filled steel tube square columns strengthened with square concrete-filled steel tube jackets

Advances in Structural Engineering ◽

10.1177/1369433219888726 ◽

2019 ◽

Vol 23 (6) ◽

pp. 1074-1086 ◽

Cited By ~ 2

Author(s):

Tao Zhu ◽

Hongjun Liang ◽

Yiyan Lu ◽

Weijie Li ◽

Hong Zhang

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Bearing Capacity ◽

Element Model ◽

Steel Tube ◽

Load Bearing Capacity ◽

Load Bearing ◽

Concrete Filled Steel Tube ◽

Experimental Parameters ◽

Modified Formula

This article investigates the behaviour of slender concrete-filled steel tube square columns strengthened by concrete-filled steel tube jacketing. The columns were realised by placing a square outer steel tube around the original slender concrete-filled steel tube column and pouring strengthening concrete into the gap between the inner and outer steel tubes. Three concrete-filled steel tube square columns and seven retrofitted columns ranging from 1200 to 2000 mm were tested to failure under axial compression. The experimental parameters included three length-to-width ( L/ B1) ratios, three width-to-thickness ( B1/ t1) ratios and three strengths of concrete jacket (C50-grade, C60-grade and C70-grade). Experimentally, the retrofitted columns failed in a similar manner to traditional slender concrete-filled steel tube columns. After strengthening, the retrofitted columns benefitted greatly from the component materials, with their load-bearing capacity and ductility notably enhanced. These enhancements were mainly brought about by sectional enlargement and good confinement of concrete. A finite element model was developed using ABAQUS to better understand the axial behaviour of the retrofitted specimens. A parametric study was conducted, with parameters including the length of the column, thickness of the outer steel tube, strength of the concrete jacket, yield strength of the outer steel tube, thickness of the inner steel tube and strength of the inner concrete. Furthermore, the finite element model was adopted to study the behaviour of rust-damaged and post-fire slender concrete-filled steel tube square columns strengthened by square concrete-filled steel tube jacketing. A modified formula was proposed to predict the load-bearing capacity of retrofitted specimens, and the numerical results agreed well with the experiments and the finite element results of undamaged, rust-damaged and post-fire specimens. It could be used as a reference for practical application.

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The Horizontal Bearing Capacity of Composite Concrete-Filled Steel Tube Piles

Advances in Civil Engineering ◽

10.1155/2020/3241602 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Yunxiu Dong ◽

Zhongju Feng ◽

Haibo Hu ◽

Jingbin He ◽

Qilang Zhang ◽

...

Keyword(s):

Bearing Capacity ◽

Soil Compaction ◽

Soil Mass ◽

Steel Tube ◽

Continuous Increase ◽

Concrete Filled Steel Tube ◽

Concrete Piles ◽

Compaction Zone ◽

Reinforced Concrete Piles ◽

Centrifugal Model

Steel casings (SCs) are extensively and increasingly used to stabilize the borehole wall in the construction of bridge pile foundations. Steel casings (SCs), together with reinforced concrete piles (RCPs), form composite concrete-filled steel tube piles (CCFSTPs), which differ significantly from ordinary RCPs in horizontal bearing capacity. In this study, based on the characteristics of CCFSTPs, the horizontal bearing capacity of a CCFSTP was examined through a centrifugal model test with the length of the steel casing (LSC) and the modulus of the soil mass in the steel casing soil compaction zone (ESCSC_zone) as variables. Pile-side soil resistance, load-displacement curves, and pile moment curves were obtained for the CCFSTP. The results show that increasing LSC within a range of 12 cm significantly increases the ultimate horizontal bearing capacity of the CCFSTP, and further increasing LSC beyond 12 cm produces a continuous increase in the ultimate horizontal bearing capacity of the CCFSTP but only to an insignificant extent. In addition, increasing ESCSC_zone increases the ultimate horizontal bearing capacity of the CCFSTP, but to a relatively small extent. The results of this study provide a theoretical basis and technical support for the design and construction of CCFSTPs.

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Experimental Study on the Axial Loading Tests of RC Columns Strengthened with Steel Tube

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.204-208.2878 ◽

2012 ◽

Vol 204-208 ◽

pp. 2878-2882 ◽

Cited By ~ 5

Author(s):

Miao Zhou ◽

Jian Wei Li ◽

Jing Min Duan

Keyword(s):

Experimental Study ◽

Bearing Capacity ◽

Axial Loading ◽

Steel Tube ◽

Experimental Results ◽

Engineering Practice ◽

Rc Columns ◽

Short Columns ◽

Loading Tests ◽

Engineering Staff

This paper carries out a series of experimental study on 6 column specimens, analyses and compares with the different parameters on the axial loading tests of RC columns and RC columns strengthened with steel tube. The experimental results show that the RC columns strengthened with steel tube take full advantage of loading properties of both materials, thus greatly improve the bearing capacity of specimens. With the same wall thickness steel tube, the improving degree of bearing capacity of long columns is bigger than the short columns, and the reinforcement effect is more obvious. The experimental results can offer reference for scientific research and engineering staff, and promote this reinforcement method to be widely used in engineering practice.

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