The Mechanical Analysis Of The Superstructure Of Wusong Irregular Bridge

In recent years,the rapid development of domestic modernization,the booming development of transportation and the increasing of urban viaduct and interchange bridge promoted the emergence of a great number of irregular bridge to meet the demands of urban traffic alignment.There were still many issues that must be resolved because of the complexity of mechanics of irregular.For example,the research document of the bearings and crossbeam layouts of the irregular bridge with lager ratio of wide-span and other aspects were less.Therefore,it's very important and practical significant to research the bearings and crossbeam layouts of the irregular bridge for the development of bridge.In this thesis,several methods of internal force analysis were introduced at the beginning of the mechanics analysis of the superstructure of bridge.The concept of beam-grid method was clear and also easy to understand and use,so the thesis used the basic principle of the theory of the beam-grid method to discrete the structure of Wusong irregular continuous box girder and then used finite element analysis software MIDAS Civil to carry on its simulation model analysis.According to the function and mechanics characteristic of the bearings and the general principles of bearings layouts,three reasonable plans of the bearings layouts of the Wusong irregular continuous box girder bridge were provided and carried on calculation analysis to them.Then more reasonable plan of bearings layouts was provided. The thesis drew up three plans of crossbeam layouts according to the function of the crossbeam. And more reasonable plan of crossbeam layouts was provided through the analysis of the three different plans of crossbeam layouts under different load case.Then the value method of the internal force of the irregular continuous bridge was provided through the analysis of the model of irregular continuous bridge.The thesis established and analyzed the model of Wusong irregular continuous box girder bridge again according to the own neutral axis of each beam-grid section. The two computed result was closed to the calculated result which was computed according to the neutral axis of the wtiole section.And this explain that it can carry on establishing and calculating the model of irregular continuous box girder according to the own neutral axis of the each beam-grid section when using the method of beam-grid to establish model and calculate.