scholarly journals Toward A Non-Prestressed Precast Long-Span Bridge Girder Using UHP-FRC

2019 ◽  
Author(s):  
Shih-Ho Chao ◽  
Venkatesh Kaka ◽  
Missagh Shamshiri
Keyword(s):  
Long Span ◽  
Long Span Bridge ◽  
Bridge Girder

scholarly journals Numerical Simulation of Characteristics of Wind Field at Bridge Sites in Flat and Gorge Terrains under the Thunderstorm Downburst

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Peng Hu ◽  
Yilin Chen ◽  
Yan Han ◽  
Fei Zhang ◽  
Yongjian Tang
Keyword(s):  
Numerical Simulation ◽  
Wind Field ◽  
Wind Fields ◽  
Monitoring Point ◽  
Wind Speeds ◽  
Flat Terrain ◽  
Long Span ◽  
Long Span Bridge ◽  
Bridge Girder ◽  
Large Wind

To investigate the effects of thunderstorm downburst on the characteristics of wind field at bridge sites in flat and gorge terrains, firstly, numerical simulation of wind fields in the flat terrain under the thunderstorm downburst was conducted through the SST k-ω turbulence model, combined with the impinging jet technology. After verification of the reliability of the numerical model, settings, and methods, the characteristics of wind field over a long-span bridge site in a gorge terrain under the thunderstorm downburst were investigated and the distributions of wind speed and wind attack angle in the flat and gorge terrains were compared. The results show that, under the effects of the thunderstorm downburst, the wind speeds are relatively maximum at the midspan point of the girder in the flat terrain. Besides, the farther away from the midspan point, the smaller the wind speeds, which is opposite to the case in the gorge terrain. The wind speeds at each typical monitoring point are basically the same in the two terrains, before the thunderstorm downburst hits the bridge girder. Later the wind speeds at each point in the gorge terrain are much higher than those in the flat terrain. Most wind attack angles are negative at the monitoring points in the flat terrain, but the farther away they are from the midspan point, the greater the wind attack angles will be. However, the wind attack angles at the monitoring points in the gorge terrain are generally larger than those in the flat terrain, and they gradually turn to be positive farther away from the midspan point. In the flat terrain, both wind speeds and wind attack angles (or their absolute values) at the girder are large within about t = 75∼130 s, indicating that the thunderstorm downburst may exert significant effects on the bridge. However, in the gorge terrain, due to the large wind speeds and wind attack angles (or their absolute values) at the girder after t = 75 s, full attention needs to be paid to the effects of the thunderstorm downburst during this period.

Flutter control of a streamlined box girder with active flaps

2020 ◽  
pp. 107754632093274
Author(s):  
Lingjun Zhuo ◽  
Haili Liao ◽  
Mingshui Li
Keyword(s):  
Control Algorithm ◽  
Suboptimal Control ◽  
Aerodynamic Stability ◽  
Box Girder ◽  
Identification Method ◽  
Long Span ◽  
Long Span Bridge ◽  
Bridge Girder ◽  
Interaction Simulation ◽  
Flutter Derivatives

Flutter control is necessary in the design of a long-span bridge. With the help of active flaps, flutter control can suppress flutter vibration and increase aerodynamic stability. This study aims to build a theoretical framework for active flutter control using a system consisting of a streamlined box girder with adjacently mounted active flaps (noted as a “deck–flap system”). An adaptive expression was proposed for the system’s self-excited forces, and an identification method was established for obtaining the system flutter derivatives in consideration of the bluff characteristics of the bridge deck and the aerodynamic interactions between the bridge girder and flaps. Then, the suboptimal control algorithm was implemented into the deck–flap system to simultaneously stabilize the divergent oscillation at the designed wind speed. Based on the proposed approach, numerical simulations were conducted to investigate the system flutter derivatives and the effectiveness of the control law. A comparison between the critical speeds of the two-dimensional flutter analysis and a fluid–structure interaction simulation showed a satisfactory performance from the theoretical model and the reliability of the identification method. The vibrations of the deck–flap system were successfully suppressed by the controlled motions of the active flaps under the application of the suboptimal control algorithm. This study provides a reliable framework for conducting an analysis of active control for bridge flutter and for significantly increasing the flutter stability of a deck–flap system.

Strait Crossing Cable Stayed Bridge Girder Evolution

2011 ◽  
Vol 250-253 ◽  
pp. 1407-1417
Author(s):  
Long Guo ◽  
Ai Rong Chen ◽  
Li Ping Xu
Keyword(s):  
Traffic Safety ◽  
Wind Load ◽  
Wind Effect ◽  
Live Load ◽  
Long Span ◽  
Long Span Bridge ◽  
Prime Concern ◽  
Structural Engineer ◽  
Earthquake Load ◽  
Bridge Girder

The design of bridges, in particular long spanned ones, is challenging in the sense that there are many complicated issues to be considered. Amidst the loads to be considered, like dead load, live load, wind load, and earthquake load, the wind load becomes the prime concern for the design of the bridges. The paper will introduce several newly evolved kinds of girder that were based on commonly known physic natural law by structural engineer. Further structural analysis and wind effect research should be done in the future to validate and decide the structural member dimensions. The main problem to be solved in strait crossing bridge is lateral wind load that will effect traffic safety as well as wind effect on structures (statically and dynamically) for long span bridge arrangement.

Handling and Shipping of Long Span Bridge Beams

PCI Journal ◽  
1987 ◽  
Vol 32 (6) ◽  
pp. 86-101 ◽  
Author(s):  
George Laszlo ◽  
Richard R. Imper
Keyword(s):  
Long Span ◽  
Long Span Bridge ◽  
Bridge Beams

scholarly journals Test Research on Toughness Evaluation of Long-span Bridge Welded Joint

2021 ◽  
Vol 787 (1) ◽  
pp. 012192
Author(s):  
Changqing Wu ◽  
Qiming Yu ◽  
Botao Zhu ◽  
Huangyi Ling ◽  
Jiaqi Zheng ◽  
...  
Keyword(s):  
Welded Joint ◽  
Long Span ◽  
Long Span Bridge ◽  
Toughness Evaluation

Super-long span bridge aerodynamics: on-going results of the TG3.1 benchmark test – Step 1.2

2019 ◽  
Author(s):  
Giorgio Diana ◽  
Stoyan Stoyanoff ◽  
Andrew Allsop ◽  
Luca Amerio ◽  
Tommaso Argentini ◽  
...  
Keyword(s):  
Numerical Models ◽  
Experimental Tests ◽  
Numerical Comparison ◽  
Aeroelastic Stability ◽  
Turbulent Wind ◽  
Long Span Bridges ◽  
Buffeting Response ◽  
Long Span ◽  
Long Span Bridge ◽  
Sectional Model

<p>This paper is part of a series of publications aimed at the divulgation of the results of the 3-step benchmark proposed by the IABSE Task Group 3.1 to define reference results for the validation of the software that simulate the aeroelastic stability and the response to the turbulent wind of super-long span bridges. Step 1 is a numerical comparison of different numerical models both a sectional model (Step 1.1) and a full bridge (Step 1.2) are studied. Step 2 will be the comparison of predicted results and experimental tests in wind tunnel. Step 3 will be a comparison against full scale measurements.</p><p>The results of Step 1.1 related to the response of a sectional model were presented to the last IABSE Symposium in Nantes 2018. In this paper, the results of Step 1.2 related to the response long-span full bridge are presented in this paper both in terms of aeroelastic stability and buffeting response, comparing the results coming from several TG members.</p>

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