考虑风速风向联合分布和地形效应的山区桥梁设计风速确定
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摘要
为研究风向对基本风速的折减,以及其与地形效应对山区桥梁设计风速确定的共同影响,以一座山区大跨度桥梁为研究背景,采用风速风向联合分布函数和计算流体力学软件FLUENT对桥址区的风场进行数值计算。首先利用桥位附近气象站的风速资料,在风速观测数据不足的情况下,采用极值Ⅰ型分布获得了风速的月极值分布和年极值分布的关系,并由此计算出不考虑风向影响的百年一遇基本风速。再应用风速风向联合分布函数,计算考虑风向影响时各个风向的百年一遇基本风速,探讨风速风向联合分布对基本风速的折减效应;并应用FLUENT软件对2种情况下的桥位区风场进行数值模拟计算,分别得到不同风向下桥位处的最大风速(即设计风速)。研究结果表明:风速风向联合分布和地形效应会对设计风速的确定产生影响。若不考虑风速风向联合分布的作用,当该地区最大基本风速的风向与地形放大效应最大的方向不一致时,会使设计风速值偏于保守。最后基于研究成果提出了可用于山区桥梁设计风速确定的分析流程,该方法更具合理性和工程实用性,可为山区桥梁设计风速的确定提供依据。
The reduction of the wind direction to the basic wind speed and topographic effect on the design wind speed of bridge in mountainous area are investigated by taking a long-span bridge crossing a deep valley as a case study.The wind field of the bridge site is numerically calculated using the joint distribution function of the wind speed and wind direction and computational fluid dynamics software,FLUENT.First,the relationship between the monthly extreme value distribution and the annual extreme value distribution is obtained using the wind speed data ofaweather station near the bridge and adopting the extreme-value type Ⅰ method when the wind speed observation data is insufficient such that the 100-year basic wind speed without considering the influence of wind direction is calculated.Second,by using the joint distribution function of the wind speed and wind direction,the 100-year basic wind speed considering the effect of wind direction is calculated to investigate the reduction effect of the joint distribution of wind speed and wind direction on the basic wind speed.FLUENT software is applied to simulate the wind field in the bridge area under the two conditions above and the maximum wind speed,namely the design wind speed,is obtained under different wind directions.The results show that the joint distribution of wind speed and wind direction and the topographic effect affect the design wind speed.If the joint distribution of wind speed and wind direction is not considered,the design wind speed will be conservative when the wind direction of the local maximum basic wind speed is different from the wind direction of the maximum terrain amplification effect.Finally,an analysis framework for determining the bridge design wind speed is proposed using the research results.This method is more reasonable and better suited for engineering applicability,and it provides a reference for the determination of the bridge design wind speed in a mountainous area.
The reduction of the wind direction to the basic wind speed and topographic effect on the design wind speed of bridge in mountainous area are investigated by taking a long-span bridge crossing a deep valley as a case study.The wind field of the bridge site is numerically calculated using the joint distribution function of the wind speed and wind direction and computational fluid dynamics software,FLUENT.First,the relationship between the monthly extreme value distribution and the annual extreme value distribution is obtained using the wind speed data ofaweather station near the bridge and adopting the extreme-value type Ⅰ method when the wind speed observation data is insufficient such that the 100-year basic wind speed without considering the influence of wind direction is calculated.Second,by using the joint distribution function of the wind speed and wind direction,the 100-year basic wind speed considering the effect of wind direction is calculated to investigate the reduction effect of the joint distribution of wind speed and wind direction on the basic wind speed.FLUENT software is applied to simulate the wind field in the bridge area under the two conditions above and the maximum wind speed,namely the design wind speed,is obtained under different wind directions.The results show that the joint distribution of wind speed and wind direction and the topographic effect affect the design wind speed.If the joint distribution of wind speed and wind direction is not considered,the design wind speed will be conservative when the wind direction of the local maximum basic wind speed is different from the wind direction of the maximum terrain amplification effect.Finally,an analysis framework for determining the bridge design wind speed is proposed using the research results.This method is more reasonable and better suited for engineering applicability,and it provides a reference for the determination of the bridge design wind speed in a mountainous area.
引文
[1]项海帆,林志兴,鲍卫刚,等.公路桥梁抗风设计指南[M].北京:人民交通出版社,1996.XIANG Hai-fan,LIN Zhi-xing,BAO Wei-gang,et al.Wind Resistant Design Guideline for Highway Bridges[M].Beijing:China Communications Press,1996.
[2]陈万隆.峡谷中风状况的分析[J].南京气象学院学报,1979,3(增1):28-33.CHEN Wan-long.Analysis of the Canyon Wind[J].Journal of Nanjing Institute of Meteorology,1979,3(S1):28-33.
[3]庞加斌,宋锦忠,林志兴.山区峡谷桥梁抗风设计风速的确定方法[J].中国公路学报,2008,21(5):39-44.PANG Jia-bin,SONG Jin-zhong,LIN Zhi-xing.Determination Method for Wind-resistant Design Wind Speed of Mountainous-valley Bridge[J].China Journal of Highway and Transport,2008,21(5):39-44.
[4]朱乐东,任鹏杰,陈伟,等.坝陵河大桥桥位深切峡谷风剖面实测研究[J].实验流体力学,2011,25(4):15-21.ZHU Le-dong,REN Peng-jie,CHEN Wei,et al.Investigation on Wind Profile in the Deep Gorge at the Balinghe Bridge Site via Field Measurement[J].Journal of Experiments in Fluid Mechanics,2011,25(4):15-21.
[5]王凯,廖海黎,李明水,等.山区峡谷桥梁设计基准风速的确定方法[J].西南交通大学学报,2013,48(1):29-35.WANG Kai,LIAO Hai-li,LI Ming-shui,et al.Determination Method for Basic Design Wind Speed of Mountainous-valley Bridge[J].Journal of Southwest Jiaotong University,2013,48(1):29-35.
[6] MILLER C A,DAVENPORT A G.Guidelines for the Calculation of Wind Speed-ups in Complex Terrain[J].Journal of Wind Engineering and Industrial Aerodynamics,1998,74-76:189-197.
[7] KIM H G,PATEL V C.Test of Turbulence Models for Wind Flow over Terrain with Separation and Recirculation[J].Boundary-layer Meteorology,2000,94(1):5-17.
[8]李永乐,胡朋,蔡宪棠,等.紧邻高陡山体桥址区风特性数值模拟研究[J].空气动力学报,2011,29(6):770-776.LI Yong-le,HU Peng,CAI Xian-tang,et al.Numerical Simulation of Wind Characteristics Above Bridge Site Adjacent a High-steep Mountain[J].Acta Aerodynamica Sinica,2011,29(6):770-776.
[9]沈炼,韩艳,董国朝,等.基于WRF的山区峡谷桥址风场数值模拟[J].中国公路学报,2017,30(5):104-113.SHEN Lian,HAN Yan,DONG Guo-chao,et al.Numerical Simulation of Wind Field on Bridge Site Located in Mountainous Site Located in Mountainous Area and Gorge Based on WRF[J].China Journal of Highway and Transport,2017,30(5):104-113.
[10] BS 5400-2:2006,Steel,Concrete and Composite Bridges,Part 2:Specification for Loads[S].
[11]刘晖,黄斌,瞿伟廉,等.多风向影响下的跨海大桥风致行车安全分析[J].地震工程与工程振动,2011,31(4):57-63.LIU Hui,HUANG Bin,QU Wei-lian,et al.Analysis of Riding Safety for a Cross Sea Bridge During Wind Exciting Considering Wind Direction Influence[J].Journal of Earthquake Engineering and Engineering Vibration,2011,31(4):57-63.
[12]韩万水,马麟,院素静,等.基于风速风向联合分布的桥面侧风所致车辆事故概率性分析[J].中国公路学报,2010,23(2):43-49.HAN Wan-shui,MA Lin,YUAN Su-jing,et al.Probability Analysis of Bridge Deck Side Wind-induced Vehicle Accidents Based on Joint Distribution of Wind Speed and Wind Direction[J].China Journal of Highway and Transport,2010,23(2):43-49.
[13]王浩,王龙花,樊星辰,等.基于健康监测的苏通大桥风速风向联合分布研究[J].桥梁建设,2013,43(5):55-61.WANG Hao,WANG Long-hua,FAN Xing-chen,et al.Study of Joint Distribution of Wind Speed and Direction of Sutong Bridge Based on SHMS[J].Bridge Construction,2013,43(5):55-61.
[14] JTG/T D60-01—2004,公路桥梁抗风设计规范[S].JTG/T D60-01—2004,Wind-resistant Design Specification for Highway Bridge[S].
[15] JENKINSON A F.The Frequency Distribution of the Annual Maximum(or Minimum)Values of Meteorological Elements[J].Quarterly Journal of the Royal Meteorological Society,1955,81:158-171.
[16]杨咏昕,葛耀君,项海帆.风速风向联合分布的平均风速统计分析[J].结构工程师,2002(3):29-46.YANG Yong-xin,GE Yao-jun,XIANG Hai-fan.Statistical Analysis of Wind Speed Based on the Joint Distribution of Wind Speed and Wind Direction[J].Structural Engineer,2002(3):29-46.
[17]于舰涵,李明水,廖海黎.山区地形对桥位风场影响的数值模拟[J].西南交通大学学报,2016,51(4):654-662.YU Jian-han,LI Ming-shui,LIAO Hai-li.Numerical Simulation of the Effect of Mountainous Topography on Wind Field at Bridge Site[J].Journal of Southwest Jiaotong University,2016,51(4):654-662.
[2]陈万隆.峡谷中风状况的分析[J].南京气象学院学报,1979,3(增1):28-33.CHEN Wan-long.Analysis of the Canyon Wind[J].Journal of Nanjing Institute of Meteorology,1979,3(S1):28-33.
[3]庞加斌,宋锦忠,林志兴.山区峡谷桥梁抗风设计风速的确定方法[J].中国公路学报,2008,21(5):39-44.PANG Jia-bin,SONG Jin-zhong,LIN Zhi-xing.Determination Method for Wind-resistant Design Wind Speed of Mountainous-valley Bridge[J].China Journal of Highway and Transport,2008,21(5):39-44.
[4]朱乐东,任鹏杰,陈伟,等.坝陵河大桥桥位深切峡谷风剖面实测研究[J].实验流体力学,2011,25(4):15-21.ZHU Le-dong,REN Peng-jie,CHEN Wei,et al.Investigation on Wind Profile in the Deep Gorge at the Balinghe Bridge Site via Field Measurement[J].Journal of Experiments in Fluid Mechanics,2011,25(4):15-21.
[5]王凯,廖海黎,李明水,等.山区峡谷桥梁设计基准风速的确定方法[J].西南交通大学学报,2013,48(1):29-35.WANG Kai,LIAO Hai-li,LI Ming-shui,et al.Determination Method for Basic Design Wind Speed of Mountainous-valley Bridge[J].Journal of Southwest Jiaotong University,2013,48(1):29-35.
[6] MILLER C A,DAVENPORT A G.Guidelines for the Calculation of Wind Speed-ups in Complex Terrain[J].Journal of Wind Engineering and Industrial Aerodynamics,1998,74-76:189-197.
[7] KIM H G,PATEL V C.Test of Turbulence Models for Wind Flow over Terrain with Separation and Recirculation[J].Boundary-layer Meteorology,2000,94(1):5-17.
[8]李永乐,胡朋,蔡宪棠,等.紧邻高陡山体桥址区风特性数值模拟研究[J].空气动力学报,2011,29(6):770-776.LI Yong-le,HU Peng,CAI Xian-tang,et al.Numerical Simulation of Wind Characteristics Above Bridge Site Adjacent a High-steep Mountain[J].Acta Aerodynamica Sinica,2011,29(6):770-776.
[9]沈炼,韩艳,董国朝,等.基于WRF的山区峡谷桥址风场数值模拟[J].中国公路学报,2017,30(5):104-113.SHEN Lian,HAN Yan,DONG Guo-chao,et al.Numerical Simulation of Wind Field on Bridge Site Located in Mountainous Site Located in Mountainous Area and Gorge Based on WRF[J].China Journal of Highway and Transport,2017,30(5):104-113.
[10] BS 5400-2:2006,Steel,Concrete and Composite Bridges,Part 2:Specification for Loads[S].
[11]刘晖,黄斌,瞿伟廉,等.多风向影响下的跨海大桥风致行车安全分析[J].地震工程与工程振动,2011,31(4):57-63.LIU Hui,HUANG Bin,QU Wei-lian,et al.Analysis of Riding Safety for a Cross Sea Bridge During Wind Exciting Considering Wind Direction Influence[J].Journal of Earthquake Engineering and Engineering Vibration,2011,31(4):57-63.
[12]韩万水,马麟,院素静,等.基于风速风向联合分布的桥面侧风所致车辆事故概率性分析[J].中国公路学报,2010,23(2):43-49.HAN Wan-shui,MA Lin,YUAN Su-jing,et al.Probability Analysis of Bridge Deck Side Wind-induced Vehicle Accidents Based on Joint Distribution of Wind Speed and Wind Direction[J].China Journal of Highway and Transport,2010,23(2):43-49.
[13]王浩,王龙花,樊星辰,等.基于健康监测的苏通大桥风速风向联合分布研究[J].桥梁建设,2013,43(5):55-61.WANG Hao,WANG Long-hua,FAN Xing-chen,et al.Study of Joint Distribution of Wind Speed and Direction of Sutong Bridge Based on SHMS[J].Bridge Construction,2013,43(5):55-61.
[14] JTG/T D60-01—2004,公路桥梁抗风设计规范[S].JTG/T D60-01—2004,Wind-resistant Design Specification for Highway Bridge[S].
[15] JENKINSON A F.The Frequency Distribution of the Annual Maximum(or Minimum)Values of Meteorological Elements[J].Quarterly Journal of the Royal Meteorological Society,1955,81:158-171.
[16]杨咏昕,葛耀君,项海帆.风速风向联合分布的平均风速统计分析[J].结构工程师,2002(3):29-46.YANG Yong-xin,GE Yao-jun,XIANG Hai-fan.Statistical Analysis of Wind Speed Based on the Joint Distribution of Wind Speed and Wind Direction[J].Structural Engineer,2002(3):29-46.
[17]于舰涵,李明水,廖海黎.山区地形对桥位风场影响的数值模拟[J].西南交通大学学报,2016,51(4):654-662.YU Jian-han,LI Ming-shui,LIAO Hai-li.Numerical Simulation of the Effect of Mountainous Topography on Wind Field at Bridge Site[J].Journal of Southwest Jiaotong University,2016,51(4):654-662.