EVALUATIONS OF FLEXURAL CAPACITY IMPROVEMENT METHOD FOR RC PIERS AND CISS FOUNDATION CONNECTIONS IN BRIDGES

Author(s):  
Jung-Kyun Kim ◽  
Hak-Eun Lee

Recently, cast-in-steel shell (CISS) pile has been used as the foundation of bridges and a pier is directly connected to the pile. In this case, plastic hinge is generally formed at the connection between the CISS pile and reinforced concrete pier. To increase the flexural capacity of such structure, a proper improvement method is necessary for the connection. In this study, a steel tube, a steel pipe that has 270mm diameter with 4.5mm thickness, has been used to enhance flexural capacity of the connection and the effect by the such method was evaluated through cyclic compression-bending test. From the test results, it can be found that the flexure capacity is considerably increased by applying the steel tube at the connection when it was compared to a general reinforced concrete (RC) pier with 10% larger diameter cross-section.

2020 ◽  
pp. 136943322098166
Author(s):  
Shuhao Yin ◽  
Bin Rong ◽  
Lei Wang ◽  
Yiliang Sun ◽  
Wuchen Zhang ◽  
...  

This paper studies the shear performance of the connection with the external stiffening ring between the square steel tubular column and unequal-depth steel beams. Two specimens of interior column connections were tested under low cyclic loading. The deformation characteristics and failure modes exhibited by the test phenomena can be summarized as: (1) two specimens all exhibited shear deformation in steel tube web of the panel zone and (2) weld fracture in the panel zone and plastic hinge failure at beam end were observed. Besides, load-displacement behaviors and strain distributions have been also discussed. The nonlinear finite element models were developed to verify the test results. Comparative analyses of the bearing capacity, failure mode, and load-paths between the equal-depth and unequal-depth beam models have been carried out.


2010 ◽  
Vol 163-167 ◽  
pp. 1574-1577 ◽  
Author(s):  
Tong Feng Zhao ◽  
Hong Nan Li ◽  
Jia Huan Yu

Moment-deformation curves of square steel tube filled with steel reinforced concrete subjected to bending load were simulated by the ABAQUS software. Calculated and experimental curves agreed well with each other. Through studying further the calculated member, the behavior of materials subjected to moment is given. Finally, flexural capacity formula of square steel tube filled with cross steel reinforced concrete is proposed.


2009 ◽  
Vol 417-418 ◽  
pp. 833-836 ◽  
Author(s):  
Qing Xiang Wang ◽  
Shi Run Liu

The test results of six connections under cyclic loading are presented in the paper. Each test specimen was properly designed to model the interior joint of a moment resisting frame, and was identically comprised of three parts that including the circular concrete filled steel tube columns, the reinforced concrete beams, and the short fabricated connection stubs. Energy dissipation was designed to occur in the beams during a severe earthquake. Steel bars which were embedded into concrete core and welded to the connection stubs, were used to transfer the force distributed by the reinforcing bars of concrete beam to the concrete core. The results indicated that the embedded steel bars were very efficient in eliminating the stress concentration on the tube wall and there was no visible deformation occurred on the tube wall until the collapse of the specimen. Furthermore, the connection of each specimen had enough capacity and thus the plastic hinge appeared in the beams. As results, the ductility of this new type structure directly depended on the RC beams.


2011 ◽  
Vol 268-270 ◽  
pp. 659-663
Author(s):  
Hua Chen ◽  
Kan Kang ◽  
Lang Ni Deng

The method of applying prestress to CFRP plates can make full use of the characteristics of high-strength, enhance the force properties, prevent peeling damage and reduce the strain lag. Construction technology of prestressed CFRP plates strengthening reinforcement concrete beams was introduce in this paper, and bending test of 6 reinforcement concrete beams strengthened with prestressed CFRP plates were carried out based on the self-developed prestressed CFRP plates supporting anchorages. The test results indicate that the flexural capacity and crack resistance capacity can be increased compared with non-prestressed CFRP plates, and the construction technology can be adopted in practical projects.


Author(s):  
R. C. Fenwick ◽  
L. M. Megget

In regions, described as plastic hinge zones, in beams and columns, tensile yielding of the reinforcement through flexural action can occur in severe earthquakes. Where the beams and columns are lightly loaded, axially, member elongation can occur. Test results show that axial extensions of the order of several percent of the member depth may be expected. This deformation, which is ignored in current design practice, can have a major influence on the distribution of forces in a structure and its ability to survive without collapse. This paper describes the way in which elongation develops in plastic hinge zones together with the form of load deflection characteristics associated with the development of different types of plastic hinge zone.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Chengzhi Wang ◽  
Xin Liu ◽  
Pengfei Li

The findings of an experimental study that was undertaken to investigate the performance of concrete-filled steel tubular members subjected to lateral loads are reported in this study. Columns of pure concrete, concrete with reinforcing bars, and two steel tube thicknesses were considered. Two different tests were conducted in this study. One test is used to research the performance of steel tube-reinforced concrete model piles under a lateral loading. The other test is used to research the effect of the depth of rock embedment for piles embedded in a foundation to simulate actual engineering applications in an experimental study. According to these test results, a detailed analysis was carried out on the relationships, such as the stress-strain and load-displacement relationships for the specimen. These tests show that the steel tube thickness and steel bars will significantly enhance the lateral bearing capacity and rigidity of the composite components. Additionally, the ultimate bending moment formula of a steel tube-reinforced concrete pile is deduced. The comparison of the calculated results with the experimental results shows that this formula is applicable for this type of pile foundation.


2011 ◽  
Vol 368-373 ◽  
pp. 410-414 ◽  
Author(s):  
Hong Zhen Kang ◽  
Lei Yao ◽  
Xi Min Song ◽  
Ying Hua Ye

To study axial compressive strength of high strength concrete-filled steel tube composite columns, tests of 18 specimens were carried out. Parameters of the specimens were the confinement index of concrete-filled steel tube, the cubic strength and the stirrup characteristic value of concrete outer of steel tube. Test results show that the concrete-filled steel tube and the reinforced concrete deformed simultaneously in the axial direction before and at the peak value of axial compressive force; after failure of the reinforced concrete, the concrete-filled steel tube can still bear the axial load and deformation; the main influential factors of axial compressive capacity are confinement index, the cubic strength and the stirrup characteristic value of concrete outer of steel tube. The accuracy of the formula of axial compressive strength of composite columns provided by CECS 188:2005 is proved by the test results of this paper.


2013 ◽  
Vol 798-799 ◽  
pp. 374-377
Author(s):  
Shuan Jiang

The ultimate tendon stress is the key to calculation of flexural capacity in reinforced concrete beam prestressed with external FRP tendons (RCBPEFT). Based on the theory of equivalent plastic hinge zone, the general formulas for calculating the ultimate tendon stress increment and ultimate tendon stress in RCBPEFT are therefore proposed. Comparisons indicate that the predictions are in good agreement with the test results.


2013 ◽  
Vol 351-352 ◽  
pp. 138-142
Author(s):  
Zhi Bin Wang ◽  
Li Ying Liu

Concrete-filled steel tube reinforced concrete (CFSTRC) columns are currently being studied as a popular method to improve the shear strength, the ductility and the seismic behaviour of reinforced concrete (RC) columns. Owing to the complexity of confinement provided by steel tubes and stirrups, the behaviour of CFSTRC column is difficult to be accurately simulated. Thus,so far there is not a finite element (FE) model for CFSTRC columns. For studying the performance of this composite column, a FE model was developed based on the existing test results and theories. The predicted results using this FE model agree with the test results, which means that this model can be applied to carry out the further mechanism analysis.


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