scholarly journals Temperature Load Parameters and Thermal Effects of a Long-Span Concrete-Filled Steel Tube Arch Bridge in Tibet

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Tuo Shi ◽  
Jielian Zheng ◽  
Nianchun Deng ◽  
Zheng Chen ◽  
Xiao Guo ◽  
...  
Keyword(s):  
Finite Element ◽  
Thermal Effects ◽  
Thermal Load ◽  
Concrete Strength ◽  
Large Diameter ◽  
Steel Tube ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Average Temperature ◽  
Cfst Arch Bridge

Zangmu Bridge is a concrete-filled steel tube (CFST) arch bridge along the Sichuan-Tibet railway in Tibet, with a main span of 430 m. Owing to the unique temperature conditions in Tibet, there have been no large-scale experimental studies on the thermal load design of CFST bridges in this area. Therefore, to determine the thermal load calculation parameters and thermal effects of Zangmu Bridge, a long-term continuous field test was conducted to measure the temperature variations in a test arch with the same pipe diameter. The test results were then compared with current design specifications and relevant literature. Finally, the thermal effects in a CFST arch bridge were analysed using the finite element method. According to the results, the following recommendations were made: (1) the average temperature of concrete in the pipe after the formation of concrete strength should be used to calculate the closure temperature of CFST arch bridges in Tibet; however, the standard calculation formula was still applicable; (2) the daily average temperature in extreme weather should be taken as the maximum and minimum effective temperature; (3) we presented recommended values for the influence range and gradient temperature for a single large-diameter pipe; and (4) a refined finite element model that included the arch base should be used to verify the temperature effects during bridge design.

scholarly journals Artificial Neural Network-Based Method for Seismic Analysis of Concrete-Filled Steel Tube Arch Bridges

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zhen Liu ◽  
Shibo Zhang
Keyword(s):  
Neural Network ◽  
Finite Element Method ◽  
Artificial Neural Network ◽  
Finite Element ◽  
Seismic Analysis ◽  
Steel Tube ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Cfst Arch Bridge ◽  
Artificial Neural

Seismic analysis of concrete-filled steel tube (CFST) arch bridge based on finite element method is a time-consuming work. Especially when uncertainty of material and structural parameters are involved, the computational requirements may exceed the computational power of high performance computers. In this paper, a seismic analysis method of CFST arch bridge based on artificial neural network is presented. The ANN is trained by these seismic damage and corresponding sample parameters based on finite element analysis. In order to obtain more efficient training samples, a uniform design method is used to select sample parameters. By comparing the damage probabilities under different seismic intensities, it is found that the damage probabilities of the neural network method and the finite element method are basically the same. The method based on ANN can save a lot of computing time.

scholarly journals Static and dynamic evaluation of a butterfly-shaped concrete-filled steel tube arch bridge through numerical analysis and field tests

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110446
Author(s):  
Gang Wu ◽  
Wei-Xin Ren ◽  
Ya-Fei Zhu ◽  
Syed M Hussain
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Field Tests ◽  
Element Model ◽  
Steel Tube ◽  
Model Errors ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Cfst Arch Bridge

The butterfly-shaped concrete-filled steel tube (CFST) arch bridge is an irregular bridge with unique esthetics. In this paper, this new shape of CFST arch bridge is introduced, and a refined three-dimensional finite element model (FEM) is established to evaluate static and dynamic behavior of the bridge. In order to reduce model errors, the FEM is calibrated according to numerical analysis and field tests. Static calculation results show that the butterfly-shaped bridge has good structural performance. The bending moment and axial force of the arch ribs increase when the camber angle of suspender changing from 15° to 50°. Dynamic test is carried out by ambient vibration testing under traffic and wind-induced excitations. The modal parameters of the bridge were calculated by the stochastic subspace identification method in the time domain. In terms of natural frequencies and mode shapes, the FEM analysis was validated by experimental modal analysis. The updated model thus obtained can be treated as a baseline finite element model, which is suitable for long term monitoring and safety evaluation of the structure in different severe circumstances such as earthquakes and wind loading in future.

Research on Overall Stability of Concrete-Filled Steel Tubular Bowstring Arch Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 1988-1994 ◽  
Author(s):  
Zi Lin Li ◽  
Pei Yuan Zhou
Keyword(s):  
Finite Element ◽  
Steel Tube ◽  
Construction Process ◽  
Ansys Software ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Overall Stability ◽  
The Stability ◽  
Tied Arch Bridge ◽  
Element Theory

Based on the finite element theory, the computational model, one through concrete filled steel tube tied-arch bridge was established under the considerations of both geometrical non-linearity and material non-linearity. And using the ANSYS software to study the bridge's arch rib construction process and the overall stability after the complete construction, the results show that the full-bridge’s stability coefficient are larger than other concrete-filled steel tube arch bridge; the in-plane stiffness is larger than the out-plane stiffness, and the influence of material non-linearity on the stability is notable. The results provide a good reference for the similar bridge's design and construction.

Outsourcing of Concrete Filled Steel Tube Strengthened CFST Axial Compression Short Columns Finite Element Analysis

2014 ◽  
Vol 525 ◽  
pp. 568-572
Author(s):  
Yang Feng Wu ◽  
Hong Mei Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Pipe Wall ◽  
Concrete Strength ◽  
Steel Tube ◽  
Element Analysis ◽  
Pipe Wall Thickness ◽  
Concrete Filled Steel Tube ◽  
Strength Grade

A new composite strengthening method that the CFST short column was strengthened with concrete filled steel tube was presented. Through the finite element analysis of five specimens with strengthening circular concrete filled steel tube columns and a specimen without strengthening circular concrete filled steel tube to explore the impact of the outer layer of concrete strength grade, external pipe wall thickness for the ultimate bearing capacity of concrete filled steel tube columns. The results show that with the increase of the outer pipe wall thickness, double concrete filled steel tube column yield strength and ultimate strength have increased. As the outer concrete strength grade increased as the specimen bearing capacity increased. When the concrete strength grade greater than C40, the improvement of concrete strength for specimen ultimate bearing capacity is not great.

A Study on Dynamic Performance of Concrete Filled Steel Tube Arch Bridges

2014 ◽  
Vol 1065-1069 ◽  
pp. 926-929 ◽  
Author(s):  
Xue Wen Dong ◽  
Qiu Yang Liu
Keyword(s):  
Analytical Method ◽  
Theoretical Study ◽  
Dynamic Performance ◽  
Steel Tube ◽  
Vibration Characteristic ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Cfst Arch Bridge ◽  
Arch Bridges ◽  
Bridge Models

With the span of CFST (Concrete Filled Steel Tube) arch bridges getting much longer, the dynamic performance of them is becoming more and more advanced. In order to evaluate the structure of CFST arch bridges in a comprehensive way, it is necessary to take the dynamic performance of this kind of bridges into consideration. Methods of doing the dynamic analysis can be divided into two kinds: one is traditional theoretical analytical method, which is only suitable for simple arch bridge models; the other is FEM (Finite Element Methods), which is able to simulate the real structure and lead to more precise results. This paper attempts to study the calculation theory of free vibration characteristic of arch bridges through theoretical analytical method, and then it will do an empirical study on the dynamic performance of a CFST arch bridge by FEM to test the conclusion of theoretical study.

The Influence of Bearing Capacity of Self-Stressed CFST Members for Different Strength Grades and Self-Stressed Magnitudes of Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 1546-1551 ◽  
Author(s):  
Shui Xing Zhou ◽  
Yue Ma ◽  
Dong Sheng Sun ◽  
Lu Li ◽  
Cheng Wu
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Concrete Strength ◽  
Steel Tube ◽  
The Self ◽  
Confined Concrete ◽  
Constitutive Relationship ◽  
Unified Theory ◽  
Concrete Filled Steel Tube ◽  
Relationship Model

According to the unified theory of general concrete filled steel tube, this paper puts forward a constitutive relationship model of the self-stressed concrete filled steel tube, which was verified by experiments and finite element methods. On the basis of the above, the influences on the bearing capacity of self-stressed CFST members were analyzed about the strength grades and magnitudes of self-stress of confined concrete. The results show that the bearing capacity of the self-stressed concrete filled steel tube members will be improved with the increase of the magnitudes of self-stress and concrete strength grades. Compared to the general CFST in the same condition, the maximum of the bearing capacity can be approximately enhanced 20%.

The Analysis of Double-Nonlinearity Stability of Concrete Filled Steel-Tube Arch Bridge

2013 ◽  
Vol 724-725 ◽  
pp. 1709-1713 ◽  
Author(s):  
Xing Han ◽  
Bing Zhu ◽  
Gui Man Liu ◽  
Jun Ping Wang ◽  
Bao Shan Xiang
Keyword(s):  
Finite Element ◽  
Nonlinear Analysis ◽  
Steel Tube ◽  
Eigenvalue Analysis ◽  
Finite Element Program ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Element Program ◽  
Load Displacement ◽  
The Stability

Taking a concrete-filled steel tube arch bridge with a span of 80m for example, the paper studies the stability of this bridge by using the general finite element program. The analysis introduces the method to deal with the stability of these bridges by FEM, also demonstrates the result of the eigenvalue analysis and dual nonlinear analysis according to an example. In eigenvalue analysis, the influence of the brace and the X-brace to this arch bridge`s stability are compared under different load cases; in dual nonlinear analysis, the load-displacement curves of three different load cases of the rib failure are given. All of these are some valuable to the stability of the concrete-filled steel tube arch bridge.

scholarly journals Axial Compression Performance and Ultrasonic Testing of Multicavity Concrete-Filled Steel Tube Shear Wall under Axial Load

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Hongbo Li ◽  
Pengfei Yan ◽  
Hao Sun ◽  
Jianguang Yin
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
Ultrasonic Testing ◽  
Axial Load ◽  
Limit Equilibrium ◽  
Concrete Strength ◽  
Shear Wall ◽  
Steel Tube ◽  
Concrete Filled Steel Tube ◽  
Core Concrete

In this study, the mechanical performance of multicavity concrete-filled steel tube (CFST) shear wall under axial compressive loading is investigated through experimental, numerical, and theoretical methodologies. Further, ultrasonic testing is used to assess the accumulated damage in the core concrete. Two specimens are designed for axial compression test to study the effect of concrete strength and steel ratio on the mechanical behavior of multicavity CFST shear wall. Furthermore, a three-dimensional (3D) finite element model is established for parametric studies to probe into compound effect between multicavity steel tube and core concrete. Based on finite element simulation and limit equilibrium theory, a practical formula is proposed for calculating the axial compressive bearing capacity of the multicavity CFST shear wall, and the corresponding calculation results are found to be in good agreement with the experimental results. This indicates that the proposed formula can serve as a useful reference for engineering applications. In addition, the ultrasonic testing results revealed that the damage process of core concrete under axial load can be divided into three stages: extension of initial cracks (elastic stage), compaction due to hooping effect (elastic-plastic stage), and overall failure of the concrete (failure stage).

scholarly journals Effects of SWS Strength and Concrete Air Void Composite Defects on Performance of CFST Arch Bridge Rib

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Zhengran Lu ◽  
Chao Guo
Keyword(s):  
Bearing Capacity ◽  
Ultimate Strength ◽  
Large Diameter ◽  
Steel Tube ◽  
Scale Model ◽  
Welding Temperature ◽  
Arch Bridge ◽  
Cfst Arch Bridge ◽  
Arch Bridges ◽  
Air Void

Most large-diameter concrete-filled steel tube (CFST) arch bridges adopt spiral-welded steel tubes for technical and economic reasons. However, during the steel tube manufacturing process, the welding temperature and other factors lead to a decreased spiral-welded seam (SWS) strength initially. Furthermore, for the CFST arch bridges using ordinary concrete, the laitance and air void defects inevitably appear, especially 20 years ago when there was no air-entraining agent in China. This paper presents a group of scale model experiments and finite element model analysis of the bearing capacity of a serviced CFST arch bridge rib with decreased SWS strength and concrete air void composite defects, under small eccentric axial compression on ultrasonic scanning field data. Parametric analyses were also performed to investigate the influence of the air void and SWS strength on the bearing capacity of the rib. Finally, a new ultimate strength index of the rib with composite defects was proposed, and a simplified formula was presented to estimate the effects of the air void and SWS strength decrease on the ultimate strength of the CFST arch bridge rib.

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