Stress Monitoring And Wind Resistance Analysis On Long-span Rigid Frame Continuous Bridge

Generally speaking, the construction of long-span bridges is rather complicatedwhich takes a considerable long time. During the cantilevered construction of Long-span prestressed concrete bridge, with the increasing number of cantilever beams, thestructural characteristics, internal force and line style changes, and these changes maycause the deviation between target value and reality. If the deviation can not be foundand made up promptly, the stress and line style would go into a bad condition, what’sworse, the closure of the bridge structure would be very difficult, leaving serious risk onthe safety of long-span bridge structures. At the cantilever status, the bridge is sensitiveto wind load, thus it may be damaged or lose its stability under wind load. In order toensure the safety of bridge during the construction and enable strength, rigidity andstability to reach the design requirements, construction monitoring and stress analysis isof great importance during the construction.In this paper, regarding bridge in the north of Changbai Mountain InternationalTourism Resort as the project instance, using professional finite element analysisprogram Doctor Bridge and Midas Civil to build simulation analysis model.Comparingthe theoretical results of the two software with each other, the accuration confirmdedthrough the analysis.Stress monitoring of the background project is taken duringcantilever construction phase.The comparation of the theoretical results with monitoringresults shows that mechanical properties of the structure conforms with design andspecification.Through static load test,a conclusion can be drawn that the bridgepossesses a good working performance,the bearing capacity and normal service capacityof it satisfy the design requirements.Then the wind effect on the bridge structure is introduced, including static actionand dynamic action, highlighting equivalent wind load calculation theory. Then basedon the analysis of vibration mode of each cantilever construction phase, conclusion canbe taken that the bridge has the poorest dynamic performance at the longest cantileveredstage. Using computational fluid dynamic to calculate static force coefficients,accordingto results of CFD,comparing the results with Chinese Wind-Resistant DesignSpecification for Highway Bridges,the changes in value assume a regular variation andthe difference in value is not large.Based on the static force coefficients each segmentforce of the bridge can be obtained through gust loading factor method.Taking windload into the Midas bridge model the results indicates that the support project is safe at the largest cantilever status under the load of wind, the results this article can be takenas convenience of reference in future.