Field measurement of basic wind characteristics oftrumpet river valley(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2020年6期
- Page:
- 47-56
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Field measurement of basic wind characteristics oftrumpet river valley
- Author(s):
- LI Jiawu1; 2; XU Runze1; 2; DANG Jiamin1; 2; ZHU Changyu1; 2; WANG Zijian1; 2
- (1. School of Highway, Changan University, Xian 710064, Shaanxi, China;2. Wind Tunnel Laboratory, Changan University, Xian 710064, Shaanxi, China)
- Keywords:
- bridge engineering; wind characteristic; field wind speed monitoring; wind profile; complex terrain
- PACS:
- -
- DOI:
- -
- Abstract:
- In order to further study the wind field characteristics of complex terrain, and at the same time obtain the wind parameters at the actual bridge site, the topography of the trumpet valley was taken as the research object for a sixmonth field measurement. In this area, rivers enter into flat areas from mountainous areas. Therefore, such river valleys have both the characteristics of mountain valleys and plains, and the landforms were complex. During the measurement, a threedimensional scanning wind lidar was used to make multipoint measurements in the river valley. The measurement points were arranged based on a local two towers cablestayed bridge. A virtual wind measuring tower was installed every 141 m along the axis of the bridge, for a total of 4 virtual wind towers. And wind profiles of these 4 measuring points were obtained. Finally, wind profiles at different locations, the average wind speed and direction at different locations and different heights in the trumpet river valley were obtained, and the wind field characteristics under the terrain were obtained through analysis. The results show that the wind speed is accelerated at a certain height, and this phenomenon mainly occurs in the middle and lower height of the river valley. The cause is related to the change of the incoming wind direction and the terrain. The wind profile of the trumpet valley is more complicated than the model listed in the windresistant design specification for highway bridges (JTG T 336001—2018), and it is difficult to describe with the existing model. But it can still be described with the power function. Affected by the incoming current and the surrounding terrain, at the height of the bridge deck, the wind speed at the midspan position is greater than the wind speed on sides when wind speed is high. Affected by the direction of the incoming flow and the terrain, there are differences in the wind direction at different locations at the height of the bridge deck. When the atmospheric wind direction is northwest, the wind direction in the valley changes greatly from low altitude to high altitude. When the atmospheric wind direction is southeast, the difference in the vertical direction of the wind direction in the valley is small. The results obtained in this paper are quite different from the current description of wind characteristics in the specification, so these results can supplement the content of the specification and also provide a reference for the prediction of wind characteristics in complex terrain. 2 tabs, 16 figs, 31 refs.
Last Update: 2020-12-17