Study On Stability Of Multi-support Ramp Bridge Under Complex Urban Traffic Load

In our country,with the great development of transportation industry,more and more highway come into use.By the end of 2015,the total mileage of highway has reached 123500 kilometers,and ramp bridge is the main bridge of the highway’s interchange connection,increased traffic line makes the ramp bridge’s form becoming more and more complex,especially in a lot of width-changed and branched ramp bridge,often using layout more bearings to meet the requirements of the structural bearing.This year the frequent occurrence of overturning accident making us to pay attention to the importance of bridge lateral stability.For such a ramp bridge,in the increasingly complex city traffic load,analysis method and the anti overturning stability can meet the requirements or not,is the main purpose of this paper,as a direction,this paper mainly as follows:First of all,this paper enumerates the domestic bridge overturning accident,analyze and contrast the domestic specification and abroad,indicate the anti overturning calculation specification lack of relevant regulations such as calculation and analysis methods of multi-bearings ramp bridge,and explore the overturning forms and the main reason for the possible occurrence of each a failure is analyzed,and then summed up on the bridge of the overturning process are expounded.Through the research and analysis of the bridge overturning accident examples,and analyzes the research,overturning checking load standard against the results of domestic scholars said that in an increasingly complex traffic load,using only the class I Highway Lane load checking on bridge lateral stability,due to lack of load values,so the calculation results for the bridge is often too dangerous.By relying on the actual project,the first is the establishment of Midas Civil finite element analysis model of the structure and anti overturning stability checking,in the bearing cavity under the condition that the possibility of overturning on the structure of the overall evaluation,then combining with the above analysis,check the lower part of the structure stability.Finally,through the comparison and analysis to the solid model,through optimization of finite element model,calculate and analyze multi support ramp bridge stress bearing in loading condition,and then checking the bearing capacity checking load bearing on the lower part of the structure,propose a strengthening solution of incompetent component.