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.

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.

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.

Live-load strain evaluation of the prestressed concrete box-girder bridge using deep learning and clustering

2019 ◽  
Vol 19 (4) ◽  
pp. 1051-1063 ◽  
Author(s):  
Hanwei Zhao ◽  
Youliang Ding ◽  
Aiqun Li ◽  
Zhaozhao Ren ◽  
Kang Yang
Keyword(s):  
Deep Learning ◽  
Gaussian Mixture Model ◽  
Mixture Model ◽  
Prestressed Concrete ◽  
Gaussian Mixture ◽  
Live Load ◽  
Box Girder ◽  
Concrete Box Girder ◽  
Box Girder Bridge ◽  
Girder Bridge

The monitoring data makes it feasible to quickly evaluate the cracking of the prestressed concrete box-girder bridge. The live-load strain can accurately quantify the load effect and cracking of bridges due to its explicit datum point of signal. Based on the live-load strain data from bridge monitoring system, this study develops a comprehensive data-driven method of state evaluation and cracking early warning for the prestressed concrete box-girder bridge. The feature of vehicle-induced strain is extracted using the deep learning and classification of long short-term memory network. The vehicle-induced strain features are clustered via Gaussian mixture model, and the cracking early warning of the bridge is conducted according to the reliability of heavy vehicle clustering data. This method can be used as an indicator for the bridge inspection, truck-weight-limit and reinforcement work. The results demonstrate that (1) using the long short-term memory network, a deep learning model can be trained to intelligently classify the non-stationary and stationary sections of vehicle-induced strains, of which the test accuracy of classification surpasses 99%, and (2) according to the Gaussian mixture model probability distribution of data, the vehicle-induced strain features can be clustered by the corresponding Gaussian mixture model crest, which is the premise for reflecting relational mapping between vehicle loading and strain response.

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.

scholarly journals Effect of Time Dependent Variables on Different Types of PSC Box Girder Bridges.

2019 ◽  
Vol 11 (02) ◽  
pp. 123-128
Author(s):  
Norine George ◽  
Kiran Umachagi ◽  
Sunil Kumar Tengli
Keyword(s):  
Cross Section ◽  
Prestressed Concrete ◽  
Cell Types ◽  
Time Dependent ◽  
Box Girder ◽  
Temperature Creep ◽  
Dependent Variables ◽  
Concrete Box Girder ◽  
Girder Bridge ◽  
Creep And Shrinkage

Time dependent variables such as temperature gradient, effective temperature, creep, and shrinkage lead to long term deflection in prestressed concrete girders. This in turn effects the serviceability and sustainability of the bridge in the long run. Therefore, research and analysis is of paramount importance before deciding the type of girder to be used. A parametric study was carried out in order to determine the most desirable and efficient type of box girder to be used for a prestressed concrete bridge having a continuous span. Three prestressed concrete box girder bridge models of single, multi-cell rectangular and multi-cell trapezoidal cross section, having similar span, width and depth were taken into consideration. The finite element models were analysed using MIDAS Civil. The behaviour of the box girder cell types under various time dependent properties such as temperature, creep and shrinkage are presented in this paper. The results show that the prestressed concrete box girder bridge of multi-cell rectangular cross section exhibits greater forces and moments due to time dependent variables in comparison to the other two box girder cell types.

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