| Bridges,as the choke point of transportation,are prone to irreversible damage due to the increasing traffic volume,natural aging of the internal structure,various external natural disasters,and the prevalence of overweight（or over-limit）vehicles,and therefore,bridge structural safety monitoring and assessment is of great importance and necessity.In the existing research on hollow slab bridge hinge joint damage,the traditional hinge joint theory is not sufficiently analyzed in the actual hinge joint internal force state and transmission mechanism,especially in considering the relative angle and relative displacement,and the research on bridge hinge joint structural damage diagnosis is mostly stagnant in the qualitative and localization stage,and accurate quantitative damage examples are not common.This paper establishes a hinge mechanics model for spring hinge joints,introduces a hinge damage calculation formula,and validates and analyzes it with actual bridge cases,and finds that the method can not only qualify the damage occurrence and locate the damage location,but also accurately quantify the damage degree.In this paper,taking an actual hollow slab girder bridge as an example,the finite element model of the hollow slab girder bridge was established by MIDAS/Civil and combined with the actual bridge test analysis,the following work was carried out.（1）Based on the analysis of the internal force state of the hinge joint and the force transmission mechanism,a hinge joint mechanics model and a hollow-core slab girder bridge calculation model are established,and the relative displacement,relative turning angle and hinge joint shear force are calculated from the deflection and turning angle to introduce the calculation formula of the hinge joint damage degree,and the relative deflection,shear force and relative turning angle are substituted into the introduced formula to calculate the lateral force and damage degree of the hinge joint.（2）Numerical simulation analysis of hollow slab girder bridge hinge joint damage was carried out,and the hollow slab girder bridge model was established by finite element software,and the hinge joint was simulated by using virtual crossbeam,and the damage was introduced by using the method of reducing the elastic modulus of the hinge joint material.The shear force,lateral force and relative displacement values inside the hinge joint were obtained by using the finite element model simulation,and the theoretical values were compared with the simulated values,and the specific values of the damage degree of the hinge joint were obtained by substituting into the equations.The results show that the simulation results are in good agreement with the values calculated by the formula,and the load location has a significant influence on the calculation results.Compared with the existing hinge plate theory,this theory has higher accuracy.（3）The stress finite element theoretical analysis of a hollow slab girder bridge was carried out to obtain the theoretical stress clouds,and the damage to the hinge joints of the hollow slab girder bridge was numerically simulated and analyzed by using the theoretical and measured values of the central deflection of the hollow slab.（4）The finite element software MIDAS/Civil was used to calculate the spatial force refinement,and the modulus of elasticity of the transverse virtual beam material was reduced in the finite element model to introduce 25% damage,and the corner values of different hinge joints and the displacement-deformation diagrams of the bridge under each working condition were obtained,and the relative displacements were calculated by the displacement values and compared with the set simulated values,and it was found that the calculated values were in strong agreement with the simulated values The calculated values were found to be in good agreement with the simulated values.The actual static load test measured the displacement and strain values of each measurement point,and the test results were analyzed using the hinge joint damage identification method based on relative displacement and relative angle of rotation to calculate the damage level of the hinge joints of the actual hollow slab girder bridge.图 [44] 表 [15] 参 [75]... |
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