利用美国WRF(Weather Research Forecast)模式对"海棠"台风(0505)登陆前后的雨带变化进行分析和模拟试验。结果显示:台风登陆前后其雨带会产生断裂,这种现象可发生在陆地和海上,使非对称降水更加明显。分析得出雨带断裂不仅...利用美国WRF(Weather Research Forecast)模式对"海棠"台风(0505)登陆前后的雨带变化进行分析和模拟试验。结果显示:台风登陆前后其雨带会产生断裂,这种现象可发生在陆地和海上,使非对称降水更加明显。分析得出雨带断裂不仅与地形有关,而且与高层台风环流和中纬度系统的相互作用有关:台风登陆前后,200hPa南亚高压和台风外围的辐散气流结合形成在台风西北方向的弱倒槽,台风中心西侧及西北侧的中低层辐散流场稳定维持,使高层气旋性流场加强,与气旋性流场相伴的正涡度一部分随气流逆时针旋转,并逐步平流至台风中心附近的正涡度区形成一个沿22～25°N的正涡度输送带并延伸至台风中心东部,而中心东部高层的正涡度带中有下沉运动,不利于降水发展而导致雨带断裂是非对称降水的主要原因。高层台风的带状涡度向外围的传播可导致中纬度气旋性环流的进一步加强和正涡度向台风输送的加强,使雨带断裂更加明显。展开更多
Field measurement on wind characteristic and buffeting response of existing bridge is of great value to the development of bridge wind engineering,and the structural health monitoring system(SHMS) em-ployed in many lo...Field measurement on wind characteristic and buffeting response of existing bridge is of great value to the development of bridge wind engineering,and the structural health monitoring system(SHMS) em-ployed in many long-span bridges provide a research basis for the field measurement.In order to pro-vide reliable basis for wind resistant evaluation of Runyang Suspension Bridge(RSB),two anemome-ters and 85 accelerometers were installed in the SHMS of RSB.In August 2005,Typhoon Matsa crossed over Jiangsu,the SHMS timely recorded the typhoon and structural vibration responses.In this paper by using the time-frequency technique and statistical theory,the recorded data were analyzed to obtain the strong wind characteristics,the buffeting response characteristics of the cable and deck,and the variation of buffeting response RMS versus wind speed.Results obtained in this study can be em-ployed to validate the credibility of current buffeting response analysis theory techniques,and provide reference values for wind resistant evaluation of other long-span bridges.展开更多
文摘利用美国WRF(Weather Research Forecast)模式对"海棠"台风(0505)登陆前后的雨带变化进行分析和模拟试验。结果显示:台风登陆前后其雨带会产生断裂,这种现象可发生在陆地和海上,使非对称降水更加明显。分析得出雨带断裂不仅与地形有关,而且与高层台风环流和中纬度系统的相互作用有关:台风登陆前后,200hPa南亚高压和台风外围的辐散气流结合形成在台风西北方向的弱倒槽,台风中心西侧及西北侧的中低层辐散流场稳定维持,使高层气旋性流场加强,与气旋性流场相伴的正涡度一部分随气流逆时针旋转,并逐步平流至台风中心附近的正涡度区形成一个沿22～25°N的正涡度输送带并延伸至台风中心东部,而中心东部高层的正涡度带中有下沉运动,不利于降水发展而导致雨带断裂是非对称降水的主要原因。高层台风的带状涡度向外围的传播可导致中纬度气旋性环流的进一步加强和正涡度向台风输送的加强,使雨带断裂更加明显。
基金Supported by the National Hi-Tech Research and Development Program of China ("863" Project) (Grant No. 2006AA04Z416)the Key Project of the National Natural Science Foundation of China (Grant No. 50538020)the Outstanding Youth Fund of the National Natural Science Foundation of China (Grant No. 50725828)
文摘Field measurement on wind characteristic and buffeting response of existing bridge is of great value to the development of bridge wind engineering,and the structural health monitoring system(SHMS) em-ployed in many long-span bridges provide a research basis for the field measurement.In order to pro-vide reliable basis for wind resistant evaluation of Runyang Suspension Bridge(RSB),two anemome-ters and 85 accelerometers were installed in the SHMS of RSB.In August 2005,Typhoon Matsa crossed over Jiangsu,the SHMS timely recorded the typhoon and structural vibration responses.In this paper by using the time-frequency technique and statistical theory,the recorded data were analyzed to obtain the strong wind characteristics,the buffeting response characteristics of the cable and deck,and the variation of buffeting response RMS versus wind speed.Results obtained in this study can be em-ployed to validate the credibility of current buffeting response analysis theory techniques,and provide reference values for wind resistant evaluation of other long-span bridges.
基金新加坡国家研究基金会(the National Research FoundationSingapore)颁发给Adam D.Switzer博士的NRF研究项目(编号:NRF-RF2010-04)厦门大学近海海洋环境科学国家重点实验室授予余凤玲博士的青年访问学者野外经费(批准号:2010-2012)共同资助
