The Analysis Of Cable Replacement Construction Monitoring Techniques For The Long-span And Cable Stayed Suspension Bridges

Cable-stayed and suspension bridges is the long-span bridges two most commonly usedbridge. When the bridge is restricted construction conditions, the use of cable-stayedsuspension architecture is often better able to reflect the technical and economic advantages.However, due to the complex structure of the force, such a bridge after working for manyyears, by the concrete creep, shrinkage, relaxation and fatigue loading cable and otherfactors, changes in the geometry and internal forces, resulting in cable-stayed redistributionof internal forces, some more than its allowed strength even broken cable, and had to changecable. As the cable-stayed suspension bridge system is a high-statically indeterminatestructure, for cable construction methods, construction site load and the changingenvironment will result in the construction process of the internal forces and displacementsdeviate from the design value, this deviation accumulated to a certain extent if not promptlyadjust or amend, for the security status of rope structure during construction will be difficultto ensure. Therefore, it is necessary for each stage of the construction of the cablereplacement thorough analysis, checking, cable-stayed theoretical values calculated tensileforce and the main beam deflection, construction control tower displacement parameters,clear construction sequence and construction of linear and strict monitoring and control ofinternal forces, to grasp the actual state of the structure, and thus control the conditions ofconstruction steps and make adjustments to prevent the accumulation of errors inconstruction, to ensure full alignment with the structural safety of the bridge. Particularitykind of bridge structure and construction of the main beam monitoring mainly linear, stressand tensile force cable-stayed "three controls "; most basic requirement is to ensure the safetyof the control structures in construction, followed must ensure that the structure lineargeometry and internal forces within the allowable error range of design requirements.The topics to Wujiang Major Bridge repair and reinforcement works as the basis, focuson the process of cable changing, the tower, beams and cable monitoring methods, resultsanalysis and cable force adjustment technique and so on. First Wujiang Major Bridgemodeling analysis, respectively using the MIDAS and ANSYS software to take advantage ofthe full-bridge model, to the initial state of the whole bridge and cable replacement process dynamic simulation; The initial state of the whole bridge, according to early detectionconclusion against the bridge the main components of disease appeared, carrying capacity fordifferent levels of component deterioration, be carrying capacity reduction, cross-sectionreduction, and thus simulate the structure of the initial state. Secondly, according to the orderof cable replacement, full bridge internal forces, stresses and cable force calculations todetermine the beginning of the rational and full bridge transducer cable tension adjustingcable tension value. Finally, cable replacement, the process of structural adjustment cableforce, changes in cable tension, and comparative analysis of theoretical calculations andexperimental results; their process of change limits for each cable force, the main towerdeviation case, as well as the main beam linear stress changes case tracking and monitoring,and timely correction in the theoretical model parameters to guide the construction of cablereplacement, give each cable replacement, cable tune the parameters of the process changes.Through the whole process of monitoring to ensure the safety of bridge construction, toensure the force after a bridge structure and alignment simultaneously satisfy the designrequirements, through further in-depth analysis summary provides reference for future similarconstruction of cable-changing.