scholarly journals Temperature Gradient and Its Effect on Long-Span Prestressed Concrete Box Girder Bridge

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
B. Gu ◽  
F. Y. Zhou ◽  
W. Gao ◽  
F. Z. Xie ◽  
L. H. Lei
Keyword(s):  
Temperature Distribution ◽  
Temperature Gradient ◽  
Prestressed Concrete ◽  
Longitudinal Direction ◽  
Measured Data ◽  
Box Girder ◽  
Long Span ◽  
Concrete Box Girder ◽  
Girder Bridge ◽  
Gradient Models

Temperature variations in the girder at two cross-sections of a long-span prestressed concrete box girder bridge (PCBG) were analysed based on measured data. The results show that the temperature distribution in the concrete box girder (CBG) is strongly influenced by its size, and the temperature distribution in the girder changes along the longitudinal direction of the bridge. To clarify the temperature distribution in the long-span PCBG bridge, a two-dimensional (2D) temperature prediction model, validated by the measured data, was proposed, and the effect of the girder size on the temperature distribution of the CBG was studied using the model. Based on the results of the studies, simplified vertical and transverse temperature gradient models that could consider changes along the longitudinal direction of the bridge were proposed and validated by using the measured data and three-dimensional (3D) mechanical finite element model (FEM) of the bridge. Then, the deformations and stresses derived from the proposed temperature gradient models and the models according to different codes were studied and compared. Finally, conclusions and recommendations for future bridge design are provided.

Research of Temperature Field of Long Span Concrete Box Girder Bridge Caused by Solar Radiation

2012 ◽  
Vol 256-259 ◽  
pp. 1635-1639
Author(s):  
Cun Ren Jiang ◽  
Jian Min Ren ◽  
Zhuo Ling Wang
Keyword(s):  
Temperature Field ◽  
Temperature Gradient ◽  
Solar Radiation ◽  
Structure Design ◽  
Box Girder ◽  
Qinghai Province ◽  
Long Span ◽  
Concrete Box Girder ◽  
Girder Bridge ◽  
Bottom Slab

When stimulate temperature field of concrete box girder caused by solar radiation with ANSYS, it’s feasible to turn boundary conditions to third boundary condition. Taking Ping'an Huangshui River Super-large Bridge in Qinghai Province for example, the research analyzes box girder temperature field distribution and deduces realistic temperature gradient mode by comparing calculations with measurements. Calculations show that bottom slab of box girder also has quite big temperature gradient which should be taken seriously in bridge structure design.

Influence of Stiffness Weakening at Construction Joints on the Deflection of Cantilevering-Cast Prestressed Concrete Box Girder

2015 ◽  
Vol 777 ◽  
pp. 34-37
Author(s):  
Hong Jiang Li
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Joint Stiffness ◽  
Finite Element Models ◽  
Box Girder ◽  
Long Span ◽  
Stiffness Reduction ◽  
Rigid Frame ◽  
Concrete Box Girder ◽  
Girder Bridge

For a long-span prestressed concrete box-girder bridge erected by the double-cantilever segmental method, concrete of segmental joints and concrete in their nearby area may be different from integrally-cast concrete in structural performances. For example, the stiffness of segmental joints could be weakened significantly. To reveal influences of weakening in the stiffness of segmental joints on the deflection at mid-span of box girder, a typical continuous rigid frame bridge in China was taken as the analysis example, and its finite element models were established. In these models, weakening joints were simulated. After the validity of finite element models were warranted, the deflection in the completed construction stage and the long-term deflection in the running period of box girder were calculated, and then the variation of these deflections with the stiffness reduction in all segmental joints was described. Results showed that, compared with the shearing stiffness reduction in segmental joints, the bending stiffness reduction played more significant role in affecting the deflection of box girder. When the weakening times of joint stiffness arrived at 100, deflection values of the box girder increased significantly. However, in the practical engineering, the determination of stiffness reduction in segmental joints according by their damages, and the incorporation of weakening segmental joints into the bearing capacity assessment for existing box girders were all worth further study.

Thermal Effects on Box Girder Concrete Bridges

2017 ◽  
Vol 738 ◽  
pp. 273-283
Author(s):  
Martin Moravcik ◽  
Lukas Krkoska
Keyword(s):  
Temperature Gradient ◽  
Prestressed Concrete ◽  
Design Procedure ◽  
Concrete Bridges ◽  
Temperature Gradients ◽  
Box Girder ◽  
Bridge Structures ◽  
Concrete Box Girder ◽  
Girder Bridge ◽  
Recorded Temperature

Thermal load, especially vertical temperature gradient, is an important factor that should be considered during the bridge design procedure. In the world, several researches focusing on temperature gradient was made, mostly in USA and China, but only a few analyzed actual temperature gradients measuring at European bridges. In this paper, short overview of temperature loading of bridge structures is described. Then, the temperature measurement of prestressed concrete box girder bridge built by launching method is analyzed. Recorded temperature gradient has been compared with temperature gradients for the concrete box girder cross section recommended by Eurocode design specifications.

Three‐dimensional nonlinear creep and shrinkage effects of a long‐span prestressed concrete box girder bridge

2018 ◽  
Vol 20 (2) ◽  
pp. 638-649 ◽  
Author(s):  
Shiwei Li ◽  
Yongqing Yang ◽  
Qianhui Pu ◽  
Deng Yang ◽  
Baolin Sun ◽  
...  
Keyword(s):  
Prestressed Concrete ◽  
Three Dimensional ◽  
Nonlinear Creep ◽  
Box Girder ◽  
Long Span ◽  
Concrete Box Girder ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Creep And Shrinkage

Study on Crack Causes and Strengthening Measures of Large Span PC Continuous Box Girder Bridges

2010 ◽  
Vol 163-167 ◽  
pp. 3551-3554
Author(s):  
Wei Peng ◽  
Zhi Xiang Zha
Keyword(s):  
Prestressed Concrete ◽  
Load Test ◽  
Box Girder Bridges ◽  
Element Analysis ◽  
Box Girder ◽  
Girder Bridges ◽  
Long Span ◽  
Concrete Box Girder Bridges ◽  
Girder Bridge ◽  
Engineering Projects

This template Based on cracks observation and finite element analysis of real engineering projects as well as bridge load test after reinforcement, causes and types of cracks in prestressed concrete box girder bridges and treating measurements are systematically studied. The results obtained from the calculation are presented to demonstrate the effect of sensitive factors, such as arrangement of longitudinal prestressed tendons, the magnitude of vertical prestressed force, temperature gradient, etc. The results show that the arrangement of longitudinal prestressed tendons and the magnitude of vertical prestressed force take key roles in cracks control of box girder webs. Lots of treating measurements are presented in accordance with different types of cracks, some of them are applied to a reinforcement engineering of a long span pretressed concrete continuous box girder bridge with cracks. Load test after reinforcement of the bridge demonstrates the reasonability of the treating measurements. Several design recommendations and construction measures about reinforcements and some sensitive factors mentioned above are proposed to control cracks.

Optimization on Closure Scheme of Multi-Span Prestressed Concrete Box-Girder Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 2369-2375 ◽  
Author(s):  
Ming Yuan ◽  
Dong Huang Yan
Keyword(s):  
Stress State ◽  
Prestressed Concrete ◽  
Box Girder ◽  
Rigid Frame ◽  
Closure Scheme ◽  
Concrete Box Girder ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Cantilever Construction ◽  
Rigid Frame Bridge

The stress state of finished bridge and service stage is influenced by various closure schemes in cantilever construction of multi-span prestressed concrete box-girder bridge. Two typical bridges—multi-span prestressed concrete continuous rigid frame bridge and girder bridge are investigated, The stress state in different closure schemes are analyzed using finite element(FE) analysis. Meanwhile, compared the healthy monitoring data, it has been found that taking the closure sequence from side span to middle span in cantilever construction of multi-span prestressed concrete box-girder bridge can lower stress of girder and pier in finished bridge stage, as well as reducing deformation of girder in service stage. Hence, the closure sequence from side span to middle span is more suitable for cantilever construction of multi-span prestressed concrete box-girder bridge.

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