A Security Assessment Analysis Based On The Evaluation Of Carrying Capacity Of Long-span Steel Trussed Bridge

With the development of society, increased car ownership; car flow is large caused varying degrees of damage to the built roads, bridges, especially the long-span bridges using time is long, change with time, environment and other factors, the bridge work state, the use of performance and bearing capacity greatly effect of. This paper takes Chongqing Jialing River Niujiaotuo steel truss as research object, adopts the theoretical study, numerical simulation, structure calculation and analysis of dynamic and static load test method of combining the safety assessment of large span steel truss bridge, and to summarize the safety assessment method for large span steel truss bridge. To provide theoretical guidance for the safe and normal operation of the bridge, the concrete research contents are as follows:(1) the use of relevant theories of bridge carrying capacity to assess the safety of the bridge, the modeling of the bridge by finite element software Midas Civil, for the evaluation of bridge bearing capacity and safety evaluation and lay the foundation for the.(2) of steel truss bridge steel structure, bridge deck and sidewalk panels, pier and bearing, expansion joints, floor system and ancillary facilities for inspection, verification of whether there are harmful to the safety of bridge structure disease, and then put forward the repair suggestion.(3) through static load tests, determination of the bridge under test load specified stress, deflection and displacement in the section, the measured values were compared with the theoretical value, in order to verify compliance with the specifications and design requirements of the bridge.(4) through the loading principle, control load test, analysis and research were to test method for static load and dynamic load test method, evaluated the load test of bridge bearing capacity based on actual results on the bridge, the theory calculation results conform to norms.(5) through the dynamic load test, the determination of vehicle load, impact coefficient of bridge under test load of the main girderself vibration frequency of dynamic characteristic parameters.(6) by visual inspection and special inspection, static load test and dynamic load test results, combined with the technical requirements of safety assessment of bridge struct ure bearing capacity calculation and analysis, to assess the overall security structure, bridge treatment and custody and provide scientific data.(7) by visual inspection, structure calculation, static load test, dynamic load test and crack observation test results, to evaluate the overall safety of the bridge structure, provides the suggestion for the bridge reinforcement and maintenance, and for the subsequent maintenance work and provide scientific data.