Experimental Study on Temperature Fields of Dumbbell-Shape Section of CFST Arch Rib and its Effects

2010 ◽  
Vol 163-167 ◽  
pp. 2564-2570
Author(s):  
Bin Yang ◽  
Jin Hua Huang ◽  
Chun Jiao Lin ◽  
Xing Kun Wen ◽  
Mao Jun Liu
Keyword(s):  
Temperature Field ◽  
Temperature Effect ◽  
Time History ◽  
Steel Tube ◽  
Hydration Heat ◽  
Temperature Fields ◽  
Molding Process ◽  
Single Wave ◽  
Arch Bridge ◽  
The Impact

Based on the investigation of a constructing dumbbell-shaped concrete-filled steel arch bridge in Nanning, Guangxi, continuous on-site experimental researches on temperature field and its effects were carried out under the influence of hydration heat of concrete in the molding process of concrete-filled dumb-bell steel tubular arch bridge. On the basis of measured data, analysis on time-history law of temperature field and its effect under the impact of hydration heat of concrete of composite structure of concrete-filled steel tubes is made. The results reveal that temperature variation of hydration heat of the concrete within the steel tube is showed as follows: “Temperature up-continuous high temperature-temperature down-balance”. The structural temperature field, generated under the effect of hydration hea in the process of molding arch rib, is nonlinear temperature field. Concrete hydration temperature effect of crown section basically changes with temperature field simultaneously, while the residual strain of arch foot section is relatively large; hydration temperature effect of L/4 Section emerges peak fluctuations in concrete pouring process and finally levels off. Hydration temperature field of concrete has a great effect on crown section, which makes the steel tube continuously withstand the tension and compression alternatively, while the influence on the arch foot steel tube is not obvious. Surface strains of L/8, L/4, 3L/8 sections of steel tube transit from single-wave peak to dual-wave peak and finally turn into a single wave peak.

scholarly journals Temperature Effects and Calculation Method of Closure Temperatures for Concrete-filled Steel Tube Arch Rib of Dumbbell-shape Section

2011 ◽  
Vol 5 (1) ◽  
pp. 179-189 ◽  
Author(s):  
Bin Yang ◽  
Jinhua Huang ◽  
Chunjiao Lin ◽  
Xinkun Wen
Keyword(s):  
Temperature Field ◽  
Temperature Effects ◽  
Time History ◽  
Steel Tube ◽  
Hydration Heat ◽  
Molding Process ◽  
Obvious Effect ◽  
Structural Temperature ◽  
Residual Internal Stress ◽  
Nonlinear Temperature

This paper has done continuous on-site experimental researches on temperature field and temperature effects that are under the influence of hydration heat of concrete during the molding process of dumb-bell CFST arch bridge. Analysis on time-history law of temperature field and temperature effects is made. Results reveal that temperature variation of hydration heat of the concrete within the steel tube is showed as follows: temperature rising-continuous high temperature—temperature dropping—equalizing. The structural temperature field, generated under the effect of hydration- heat in the process of molding arch rib, is nonlinear temperature field. Temperature field of concrete hydration heat has an obvious effect on crown section. Finally, practical methods to calculate the closure temperature of CFST arch rib and the effective measures to reduce the residual internal stress of temperature of arch rib are proposed.

Novel Hanger Design to Improve the Robustness of Through Arch Bridges

2011 ◽  
Vol 90-93 ◽  
pp. 862-868
Author(s):  
Qi Ming Wu ◽  
Dang Qi Yang ◽  
Fei Cui ◽  
Xiao Wei Yi ◽  
Rui Juan Jiang
Keyword(s):  
Progressive Collapse ◽  
Time History ◽  
Structural Members ◽  
New Approach ◽  
Arch Bridge ◽  
Structural Robustness ◽  
Arch Bridges ◽  
Dynamic Time ◽  
The Impact ◽  
Emergency Measures

Hangers in through arch bridges are important components since they suspend the bridge deck from the arch ribs. Local damage at a hanger may lead to progressive damage of various components in the arch bridge or even progressive collapse of the bridge. In this paper, the conventional design of double-hangers in through arch bridges is reviewed. Then a new approach to design the double-hangers is put forward. The suitability and robustness of this approach is then verified by a numerical simulation of a real through arch bridge. The impact effects induced by local hanger fracture on other structural members are simulated by dynamic time-history analyses. The new approach to design the hangers for through arch bridges is shown to improve the structural robustness. With the application of the new way put forward here, when one or more hangers are damaged to fail, the through arch bridge will not be endangered and will still maintain the overall load-bearing capacity during an appropriate length of time to allow necessary emergency measures to be taken, which illustrates the leading principle of structural robustness well.

IMPACT FORCE RESPONSE OF SHORT CONCRETE FILLED STEEL TUBULAR COLUMNS UNDER AXIAL LOAD

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1361-1368 ◽  
Author(s):  
GOUPING REN ◽  
ZHU LI
Keyword(s):  
Impact Force ◽  
Time History ◽  
Material Model ◽  
Critical Energy ◽  
Steel Tube ◽  
Peak Force ◽  
Impact Speed ◽  
Tubular Columns ◽  
Unitary Model ◽  
The Impact

The impact test on short concrete filled steel tubular column was conducted through DHR-9401 dropped hammer tester. Based on analysis on recorded time-history curve of impact force, the relations of impact force with respect to confining effect coefficient and impact speed are obtained. So are done that of the impact duration. By use of ANSYS/LS-DYNA, values of impact peak force in relation with those of impact speed were computed in the case of unitary material model and composite material model respectively. The simulation results show that peak force-speed curve of unitary model has better description of test data than that of composite one. Critical energy is found to increase linearly with the steel ratio when steel tube and concrete remain unchanged.

Numerical Analysis on the Temperature Distribution of Steel Tube Reinforced Concrete Columns Subjected to 3-Side Heating

2012 ◽  
Vol 170-173 ◽  
pp. 2657-2660
Author(s):  
Lei Xu ◽  
Yu Bin Liu
Keyword(s):  
Temperature Field ◽  
Concrete Columns ◽  
Theoretical Models ◽  
Heating Time ◽  
Steel Tube ◽  
Area Ratio ◽  
Core Area ◽  
Temperature Fields ◽  
Nonlinear Fem ◽  
Section Surface

The temperature fields of steel tube filled concrete columns are analyzed by a nonlinear FEM model in the paper. The theoretical results are validated by relative test results, and a good agreement is obtained. Using the theoretical models, the influencing laws of temperature rising time; section perimeter; steel reinforcement ratio and sectional core area ratio on temperature field of STRC subjected to 3-side fire are further discussed. By above parametric analysis, it has been found that the effects of heating time, sectional dimension and sectional core area ratio on temperature field are significant, but steel ratio has very little effect on temperature both of steel tube and of section surface.

Experimental Research and ANSYS Analysis of Temperature Field of Concrete Specimens Reinforced by Paste Method in the Fire

2013 ◽  
Vol 405-408 ◽  
pp. 2677-2680
Author(s):  
Yan Bo Li ◽  
Jian Zhong Liu ◽  
Su Juan Fu
Keyword(s):  
Mechanical Properties ◽  
Temperature Field ◽  
High Temperature ◽  
Experimental Research ◽  
Fire Retardant ◽  
Experimental Results ◽  
Temperature Fields ◽  
Ansys Analysis ◽  
Reinforcement Material ◽  
The Impact

In this paper, the temperature fields of concrete specimens reinforced by paste method were analyzed by experiment and ANSYS in the fire, it proved that the impact of reinforcement material on the temperature field of the specimens can be ignored, it identified that the best thickness of the fire-retardant coating is 40mm for steel-confined specimens and 50mm for CFRP-confined specimens. The calculations agreed well with the experimental results, it provides conditions for mechanical properties of the concrete reinforced by paste method at high temperature.

Impact Factor Statistics Analysis of Concrete Filled Steel Tube Arch Bridge Considered Random Roughness of Bridge Deck

2015 ◽  
Vol 648 ◽  
pp. 80-88
Author(s):  
Xiang Wei Hao ◽  
Feng Ma ◽  
Qing Yang Ma
Keyword(s):  
Impact Factor ◽  
Bridge Deck ◽  
Steel Tube ◽  
Statistic Analysis ◽  
Coupling Vibration ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Random Roughness ◽  
Vehicle Impact ◽  
The Impact

The essence of the axle coupling vibration in case of random bridge deck is random vibration, therefore, it is quite necessary to research the effect of vehicle impact on basis of statistic analysis. With some large concrete-filled steel tube arch bridge as the object, by applying a self-made analysis program on axle coupling vibration that was demonstrated by a dynamic test, a dynamic response analysis on axle was implemented for many groups of random roughness swatches. On basis of the analysis result, a statistic analysis was conducted for the dynamic impact effect of bridge under the conditions of different deck status and vehicle speeds, in the determination of vehicle speed and roughness, the impact factor obeys the normal distribution. The analysis result shows that, the level of deck status may apparently affect the mean value and the MSD(mean square deviation), the differences of vehicle impact factors in case of different assurance rates are large. It will effectively improve the reasonableness and scientificalness of the value of a vehicle impact factor to determine the impact factor according to the level of bridge importance and a statistic analysis method.

Sensitivity Analysis on Dynamic Properties of Large Span Concrete-Filled Steel Tube Arch Bridge

2012 ◽  
Vol 204-208 ◽  
pp. 1976-1979
Author(s):  
Hang Sun ◽  
Xiao Jian Han ◽  
Xiu Yun Gao
Keyword(s):  
Dynamic Properties ◽  
Steel Tube ◽  
Design Parameters ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Space Model ◽  
Long Span ◽  
Current Design ◽  
Arch Bridges ◽  
The Impact

The calculation formula of the vertical fundamental frequency of arch bridge has been given in current design codes, in which the rise-span ratio is the only variable on condition that the structure mass and stiffness are known. However, the dynamic properties of long-span concrete filled steel tube arch bridges have their own characteristics, which are influenced by a series of factors. Thus this article establishes a space model of a concrete-filled steel tube arch bridge. By analyzing the main design parameters’ influence on the structure dynamic properties, including rise-span ratios, arch-axis coefficient and wide-span ratios, some of conclusions has been made, which can be used for further research of the impact effect and earthquake dynamic response, and provide the necessary basis for the dynamic design of bridges of this kind

Dynamic Response of a Heterotypic Concrete Filled Steel Tube Arch Bridge Subjected to Moving Vehicles

2011 ◽  
Vol 255-260 ◽  
pp. 1696-1700
Author(s):  
Yan Li ◽  
Xin Yi Huang
Keyword(s):  
Surface Roughness ◽  
Dynamic Response ◽  
Impact Factor ◽  
Damping Ratio ◽  
Steel Tube ◽  
Impact Factors ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Moving Vehicles ◽  
The Impact

As a new type structure, the dynamic behavior of the irregular concrete filled steel tube arch bridge under moving vehicles was rarely studied. In this paper, taking the bridge crossing Yitong river in Changchun of China as an example, the dynamic response of the bridge is investigated by the self-compiling vehicle-bridge coupled vibration analysis program. The surface roughness and vehicle speed are considered in the analysis. The results show that impact factors of the bridge increase as surface roughness deteriorated; the impact factor varies obviously for the different component; the tension impact factor of the short suspender is larger than that of long ones; damping ratio of structure has little effect on the impact factors. The research conclusions can be referred in the design and assessment for the similar bridges.

Seismic Assessment of RC Arch Bridge: A Case of 2015 Gorkha Earthquake

2019 ◽  
Vol 15 (1) ◽  
pp. 47-53
Author(s):  
Prakash Gaire ◽  
Ma Hongwang
Keyword(s):  
Ground Motion ◽  
Time History ◽  
Time History Analysis ◽  
Nonlinear Time History Analysis ◽  
Gorkha Earthquake ◽  
Arch Bridge ◽  
History Analysis ◽  
2015 Gorkha Earthquake ◽  
Seismic Force ◽  
The Impact

Nepal Himalayas is one of the most seismic vulnerable zones. The active tectonic action impels the assessment of structures in possible seismic hazards including the bridge structures. This paper presents the impact of the 2015 Gorkha earthquake on the existing reinforced concrete arch bridge at Chobhar, Nepal. A three-dimensional model of the bridge is constructed using Open Sees platform. Nonlinear pushover analysis was performed to find the displacement capacity of the bridge. Ground motion from the main shock of the 2015 Gorkha earthquake is used in this study. Nonlinear time history analysis is performed with three orthogonal ground motions applied in the transverse, longitudinal and vertical direction of the bridge. The study investigates the safety of the bridge scaling up the ground motion to potential PGA in Nepal Himalayas; the result demonstrated the necessity of retrofit to ensure the safety level. Moreover, the horizontal seismic force obtained from the time history analysis is compared with the force obtained from the design code of the bridge. Also, the design force as per the present code (revised code) is presented.

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