Study On The Assessment Technology Of The Health Status Of Railway Bridge

Railway is an important part of national transportation network, and it is also a lifeline of national economy. Railway bridge acts as a node project of railway, it is a core part to the constructon of railway, plays an extremely important role in the development of national economy. Rapid assessment of the health condition of railway bridge under the operating state has an importantly practical significane for ensuring traffic safety and improving society efficiency. This paper studies the health condition assessment of railway bridges under the operating state, the main work as follows:Firstly, the hidden trouble of railway bridge in our country is analysed, and the importance of traffic safety of railway bridge is illustrated. Content and method of condition assessment of bridge are introduced. Through analysis, the layered synthetical evaluation method is selected to assess the health condition of railway bridge, and the binary comparision method is used to calculate weight of the indicators in each layer of railway bridge.Secondly, based on analysis of the latest assessment specifications of railway bridge, combined with structural characteristics and developing trends in railway bridge, according to the different driving speed, the paper divides railway bridge into the ordinary railway bridges and the high-speed railway bridges, and it sets up the index systems of health condition assessment in their respective bridges. The ordinary railway bridge includes steel plate girder bridge, steel truss bridge, concrete beam bridge, top bearing type concrete arch bridge, half-through bearing type concrete arch bridge, through bearing type concrete arch bridge, continuous rigid frame bridge, slant leg rigid frame bridge, steel cable-stayed bridge, steel suspension bridge; The high-speed railway bridge is divided into prestressed concrete beam bridge, prestressed concrete continuous rigid frame bridge, steel plate girder bridge, concrete deck arch bridge, arc bridge, steel truss arch bridge and steel cable-stayed bridge.Thirdly, in study of the health condition assessment of railway bridge based on field investigation, the paper compiles the corresponding damage or disease field surveys of railway bridge and formulates the corresponding assessment description of each grade. In study of the health condition assessment of railway bridge based on health monitoring system, combining with the relevant knowledge of matter-element extension evaluation method and probability theory and mathematical statistics, the paper realizes assessment and point of the underlying index in each assessment index system, and evaluates the health condition of railway bridge in form of scoring for the first time.Finally, the paper puts forward bridge health index(BHI) to characterize the health condition of railway bridge, and gives the corresponding formula of condition assessment. With the measured data of Wuhan Yangtze river, the paper introduces how to carry out the health condition assessment of railway bridge based on field investigation and the health condition assessment of railway bridge based on health monitoring system.