Disease Analyses And Monitoring In Maintenance Process Of Half-through CFST Arch Bridges

Due to the early construction of concrete-filled steel tube arch bridges have a series of limitations in design,construction and other aspects,many of the early concrete-filled steel tube bridges have different degrees of diseases in the process of the operation,and it lack the necessary maintenance and repair.The old bridge maintenance reinforcement problem is getting more and more attention from the academic and engineering.Working out a suitable maintenance plan of the old bridge is admittedly important,but the construction monitoring in the process of the maintenance and reinforcement of the old bridge(especially with large span and complex bridge)is the important measures and means to ensure the construction quality,the construction safety and to achieve the goals of the expected reinforcement.The Mingshen line overpass of Songyuan city is one of the current domestic large-span concrete-filled steel tube arch bridge.The construction process of the bridge maintenance and reinforcement is complex and difficult,so it is more difficult to control the construction.In order to ensure the construction quality and safety of the bridge maintenance and reinforcement engineering and to make suspender force,the stress of arch rib,the elevation of lifting point and arch rib deformation meeting the design requirements after the completion of the bridge construction,the author of this paper as one of the monitoring personnel was involved in the whole monitoring of the bridge maintenance and reinforcement construction process.The main contents of this paper are as follows:(1)This paper explores some common diseases of concrete-filled steel tube arch bridges and analyses the disease causes of the concrete filled steel tube arch bridge arch rib,cable component,the bridge deck system and other parts from the aspects ofmaterial,environment,design and construction.(2)According to the specific diseases of the Mingshen line overpass of Songyuan city formulate the bridge’s specific maintenance and reinforcement of the construction program and monitoring program.Formulate strengthening construction plan and monitoring plan specific maintenance.(3)Using the finite element software,the full bridge model is established.We analyze the influence of the dead load change of the suspender force and the stability of the main arch.And we analyze the influence of the dead load change and the temperature change on the deformation of arch rib and the elevation of lifting point.(4)The theoretical value of the numerical simulation is used as a reference for the actual construction monitoring,which can ensure the final cable force,We monitor and control the elevation of lifting point,the suspender force and the stress of arch rib of the Mingshen line overpass in Songyuan city,the deformation of the main arch and the state of the bridge to meet the design requirements.