Analysisofinherentdefectsanddamagemechanism

The trussed combination arch bridge originated by our country in the 1980's , is a new type. Compared with traditional truss bridge, it is simple and economical, so it has developed rapidly in the past 20 years. Some unpreview diseases continunously arisen in the course of using and popularization.The outstanging problems are concrete cracks and stucture dynamic poor performance.The bridge diseases affect the normal use of the bridge.The application of the trussed combination arch bridge began to be doubted by engineering field,and the new bridge of this kind is banned.The poor performance bridges has been reinforced or lower load,and some have been demolished.The common diseases is summarized through the collection and analysis of investigation reports.The inherent defect of the trussed combination arch bridges consists of structure defect,design defect and construction defect.Firstly,take Yuan Cun Bridge for example,the stucture defect is analyed by local modal established by MIDAS-FEA.The conclusion is that there are main structure defect at solid-web section, twin vertical sticks and supferior sticks.Secondly,stucture desige defect is analyed by the simulation model of the trussed combination arch bridge.The conclusion is that there are defect of the desige paramet- ers choice.Finally,the construction defect is analyed through the construction technology of trussed combination arch bridges.The paper conclusion is that the structure defects is the deep reason of the diseases of the trussed combination arch bridge,and desige defect is the hidden dangers,and construction defects deteriorate diseases development.