Model Test On Vehicle-Bridge Couped Vibration For The Long-span Bridge With High-pier

With China's rapid development of road transportation, high-pier and long-span continuous beam bridge and continuous rigid frame bridge have been widely applied in our country. Particularly in the western gully region, this bridge often becomes the preferred solution because of its strong span ability and economy. To the research of vehicle-bridge coupling vibration for this type of bridge, we mainly use real bridge test and the finite element numerical method. However, there is little research to vehicle-bridge coupling effect of high-pier and long-span bridges by the method of model test. In view of model test which enjoys the characteristics of economy, pertinence and accurate results, it is necessary to study the model test of vehicle-bridge coupling vibration.This paper supplemented by the ministry of communications technology projects:"Study on Couping Vibration of Vehicle-Bridge in the High-pier&Long-span Continuous Rigid Frame Bridge" and, it is based on the model test to analyze and explore the problems of vehicle-bridge coupling vibration, combining theory with practice. It adopts a rigid-continuous combination system bridge as real bridge, based on the similarity principle and dimensional analysis, then determines the similarity criteria which must be followed in model design, and designs a 1/20 large scale model bridge according to the static and dynamic similarity between model and real bridge, and also designs the static-dynamic test scheme of model bridge.According to the characteristics of vehicle-bridge coupling test, we analyze the model bridge by finite element numerical method. Main analysis including:the influence to the frequency of bridge when model car on different positions, the response of vehicle-bridge coupling vibration system under positioning disturbing force, the response of vehicle-bridge coupling vibration system when a vehicle through the bridge at different speeds. At the same time in the laboratory we make static tests and test the displacement and strain of control sections. Dynamic tests mainly test the characteristics such as natural frequency, vibration mode and damping ratio, and also test the influence to the frequency of bridge when model car on different positions and the response of vehicle-bridge coupling vibration system under positioning disturbing force. Combining the finite element numerical analysis results and actual results analyse the variations of bridge frequency.In order to better combine the finite element model and actual model, we apply the optimization analysis function of ANSYS, study the finite element model updating method of vehicle-bridge coupling which based on actual data, and make use of the displacement from static test and frequency from dynamic test as state variables, to update the finite element model by constructing objective function.