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
In this dissertation, wind, vehicle and bridge are regarded as an interacting coupling vibration system. In the analysis model of the system, many factors are considered in detail, such as the fluid-solid coupling int...In this dissertation, wind, vehicle and bridge are regarded as an interacting coupling vibration system. In the analysis model of the system, many factors are considered in detail, such as the fluid-solid coupling interaction between wind and bridge, the solid contact coupling interaction between vehicle and bridge, the stochastic wind load of vehicle, the time variation characteristics of the system induced by train movement. The main research achievements are as follows:Firstly, a reliable but simple identification method by the name of the Weighting Ensemble Least-Square method (WELS), has been developed to extract flutter derivatives of bridge deck from free vibration records. According to the properties of both the structural style and the vibration mode of long cable-stayed bridge, and considering the correlation characteristics of natural wind, a practical method is introduced to simplify stochastic wind velocity field of long cable-stayed bridges for taking pylon wind field effect into account. The method turns a three-dimension stochastic wind field on a plane into one-dimension stochastic wind fields on lines. The computational work of simulating wind velocity field is reduced by a big margin by the method. Based on wind speed observation record with drawback, it is proved that the exponent expressing terrain roughness can be calculated according to the monthly maximum wind speed records at various height levels. Wind gradient characteristics on bridge site are determined by statistical method. In order to measure respective aerodynamic parameters of deck and vehicle when vehicle is on deck, a simple but well-performed device is developed, which is called Crossed Slot System. The device can separate the wind loads on bridge and on vehicles from each other. Based measured aerodynamic parameter and simulated wind speed field, time-domain expression of static wind load, buffeting load and self-excited load for bridge and vehicle are introduced.Secondly, Germany high-speed spectrums with weak disturbance ar展开更多
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.
文摘In this dissertation, wind, vehicle and bridge are regarded as an interacting coupling vibration system. In the analysis model of the system, many factors are considered in detail, such as the fluid-solid coupling interaction between wind and bridge, the solid contact coupling interaction between vehicle and bridge, the stochastic wind load of vehicle, the time variation characteristics of the system induced by train movement. The main research achievements are as follows:Firstly, a reliable but simple identification method by the name of the Weighting Ensemble Least-Square method (WELS), has been developed to extract flutter derivatives of bridge deck from free vibration records. According to the properties of both the structural style and the vibration mode of long cable-stayed bridge, and considering the correlation characteristics of natural wind, a practical method is introduced to simplify stochastic wind velocity field of long cable-stayed bridges for taking pylon wind field effect into account. The method turns a three-dimension stochastic wind field on a plane into one-dimension stochastic wind fields on lines. The computational work of simulating wind velocity field is reduced by a big margin by the method. Based on wind speed observation record with drawback, it is proved that the exponent expressing terrain roughness can be calculated according to the monthly maximum wind speed records at various height levels. Wind gradient characteristics on bridge site are determined by statistical method. In order to measure respective aerodynamic parameters of deck and vehicle when vehicle is on deck, a simple but well-performed device is developed, which is called Crossed Slot System. The device can separate the wind loads on bridge and on vehicles from each other. Based measured aerodynamic parameter and simulated wind speed field, time-domain expression of static wind load, buffeting load and self-excited load for bridge and vehicle are introduced.Secondly, Germany high-speed spectrums with weak disturbance ar
