Evolution of long-span bridge response to wind-numerical simulation and discussion

2003 ◽  
Vol 81 (21) ◽  
pp. 2055-2066 ◽  
Author(s):  
S.R. Chen ◽  
C.S. Cai
2019 ◽  
Vol 19 (12) ◽  
pp. 1950149
Author(s):  
Shenghong Huang ◽  
Qiusheng Li ◽  
Man Liu ◽  
Fubin Chen ◽  
Shun Liu

Wind-driven rain (WDR) and its interactions with structures is an important research subject in wind engineering. As bridge spans are becoming longer and longer, the effects of WDR on long-span bridges should be well understood. Therefore, this paper presents a comprehensive numerical simulation study of WDR on a full-scale long-span bridge under extreme conditions. A validation study shows that the predictions of WDR on a bridge section model agree with experimental results, validating the applicability of the WDR simulation approach based on the Eulerian multiphase model. Furthermore, a detailed numerical simulation of WDR on a long-span bridge, North Bridge of Xiazhang Cross-sea Bridge is conducted. The simulation results indicate that although the loads induced by raindrops on the bridge surfaces are very small as compared to the wind loads, extreme rain intensity may occur on some windward surfaces of the bridge. The adopted numerical methods and rain loading models are validated to be an effective tool for WDR simulation for bridges and the results presented in this paper provide useful information for the water-erosion proof design of future long-span bridges.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Peng Hu ◽  
Yilin Chen ◽  
Yan Han ◽  
Fei Zhang ◽  
Yongjian Tang

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.


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5584
Author(s):  
Zhi-Yong Yang ◽  
Xiang Zhan ◽  
Xin-Long Zhou ◽  
Heng-Lin Xiao ◽  
Yao-Yao Pei

The cross beam of a long-span bridge will freeze in low temperature. When the temperature rises, the ice on the cross beam will thaw and fall off. If the ice is too heavy, it may cause vehicle damage and casualty. In order to reduce the risk of falling ice, a scale model of the cross beam was taken as an example, and a kind of numerical simulation method is presented to study the icing distribution characteristics on surface of the cross beam. This paper simulates the ice accretions process of the cross beam by Fluent module and FENSAP-ICE module of ANSYS and investigates the influence of wind and temperature in the process. This is a new numerical simulation method for studying ice accretions of buildings. The results indicate that water freezes mainly on the windward surface, and the thicker ice is near the top and bottom edge of windward surface. According to the results of numerical simulation, a measure of ice melting based on electric heating method is proposed in this paper, and the feasibility and effectiveness of this method are verified by numerical simulation. The results show that the icing distribution characteristics are accord with the fact and the ice-melting measure is feasible and effective.


2013 ◽  
Vol 361-363 ◽  
pp. 1094-1100
Author(s):  
Jian Guo ◽  
Wei Chang Gan ◽  
Ding Yu Jiang ◽  
Bing Nan Sun ◽  
Wei Peng

In the research on calculation of interaction of wind and structure, the key to the question is wind field numerical simulation. This paper introduces a practical wind field simulation method of long-span Bridge. The main bridge of Jintang Bridge was analyzed as engineering example, which is a cross-sea cable stayed bridge in Zhoushan of Zhejiang Province , and the linear filter method was applied to calculate along-wind and vertical wind field on main girder, MATLAB program also was adopted to simulate wind field of long-span Bridge. The results show that simulated spectrum is in better agreement with the target spectrum, which verifies validity of the method and correctness of the program.


2011 ◽  
Vol 255-260 ◽  
pp. 1134-1137
Author(s):  
Bing Bai ◽  
Ze Yu Wu ◽  
Xiao Shan Deng

Based on the numerical simulation and finite element method, the longitudinal seismic action of a long-span continuous bridge is systematically analyzed. Four load cases are considered, i.e. bridge without piers, bridge with piers, neglecting friction force and combining friction force and pier scouring respectively. Calculation results show that: when considering the piers, the contribution of piers to bridge longitudinal seismic forces is depending on the concrete problems; when the friction force of rubber supports is regarded, sliding support greatly enhances the longitudinal overall rigidity of the bridge, but the force is resolved to each rubber support and can improve the stress state of the fixed support; considering effect of scouring, the elongation of piers will lead to the decrease of longitudinal overall rigidity, thereby lowering the longitudinal seismic forces. From comparison of the two piers that, the relatively flexible structure has shock absorption to a certain extent, so it is more suitable for the bridge.


2012 ◽  
Vol 204-208 ◽  
pp. 3369-3372
Author(s):  
Chun Guang Li ◽  
Zheng Qing Chen ◽  
Zhi Tian Zhang

With the increase of the span length of bridge, the wind field characteristics at bridge site play crucial role for the safety of bridge. The present paper discusses the results of a numerical simulation of the wind flow over mountainous area called Aizhai, located in Hunan province, where a super long span bridge with main span of 1176m will be constructed. The results indicate that it is inappropriate to describe the mean wind velocity profiles by power law using the same roughness exponent along the span wise direction in the mountainous valley terrain. The speed-up effect and the significant change in wind direction of the mean flow were observed, which provide the information necessary for determining the design wind speed such as for a long span bridge across the valley.


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