Optimum Design Of Spherical Hinge Structure And Rotation State Evaluation Of Horizontal Swivel Bridge

In recent years,with the continuous improvement of bridge construction technology,the swivel construction method is emerging in bridge construction.With the advantages of less interference to the existing offline traffic operation,the swivel construction method is widely used in the bridge engineering practice across the existing lines(especially the railway).However,the current spherical hinge design theory of a swivel bridge is conservative,and the control of spherical hinge size is mainly based on experience.There is no unified conclusion on the force state of the spherical hinge and its slider,and the theoretical solution process are relatively simple,so it is impossible to accurately describe the force of the spherical hinge.The complex construction process and many uncertain factors lead to less achievements in construction monitoring and risk management of the bridge.In this paper,based on a horizontal topic project "based on the awareness of spherical hinge structure optimization and condition assessment of a swivel bridge",based on the structure characteristics of the swivel Bridges,the ball joint of bridge structure optimization and spin state evaluation and early warning system were studied,to design and construction of bridge structure provides theoretical basis and technical support.The main research contents of this paper are as follows:1.Static characteristics analysis and optimization design of spherical hinge structure of a swivel bridge.Relying on the project of Beijing-Harbin railway revolving bridge on xing fu road in chang chun new district,a fine calculation model of the actual project is established by using finite element analysis,and the force analysis is carried out.The influence of curvature radius,pin radius,support radius,pin depth and other design parameters on mechanical characteristics of spherical hinge structure is systematically analyzed.Based on Box-Behnken test design method,the influence factors of supporting radius,curvature radius and pin radius of spherical hinge structure were evaluated theoretically,and the optimal optimization parameters of spherical hinge structure with a swivel bridge were determined.2.Analysis of dynamic characteristics of a swivel bridge.The maximum torsional shear stress,angular acceleration and inertial braking distance in the process of a swivel bridge are determined by theoretical analysis and derivation.Through the establishment of the swivel bridge under different angular velocity and angular acceleration of the fine calculation model,stress state in the process of turning the slider and the upper structure system is discussed.It is found that the stress state of the spherical hinge slider and the superstructure is less affected by the angular acceleration and the angular velocity,and the superstructure are the sensitive component in rotation process.3.Study on stability against overturning of a swivel bridge under various dangerous conditions.Through finite element analysis,the influence of wind loadseffective,moment of unbalanced traction force,unbalanced counterweight and deflection of superstructure on the structural state of the swivel bridge is discussed.The control parameters of the critical overturning of the swivel bridge under various working conditions and the supporting functions of the pins and struts are determined.A single power traction system of a swivel bridge is presented,it can guarantee the swivel force always equal on both sides of the spherical hinge structure,smooth speed,effectively avoid the swivel hinge transverse tension,improve the quality of swivel Bridges in rotation phase,and can reduce other requirements for the multiple traction,effectively save the construction cost,has good generalization.4.Effectiveness studies of scale model of a swivel bridge with large scale.Based on the dimensional analysis method,the similar function of the swivel bridge is deduced,and the similarity and validity of the scaling model of the swivel bridge are discussed by the finite element analysis method.In this paper,the local distortion phenomenon of spherical hinge of a swivel bridge with large scale is discussed,and by comparing the prediction effect of three existing distortion correction models,a correction prediction method suitable for the size distortion of the scale model of this project is put forward.According to the design requirements,the indoor scale model of the spherical hinge structure was prepared,according to the design requirements,the indoor scale model of the spherical hinge structure was made,and the indoor test and measurement scheme were designed.The validity of the distortion model of the spherical hinge structure was verified.5.Research on dynamic monitoring and risk early warning system of the swivel structure based on self-sensing spherical hinge.In this paper,an indoor model of bridge rotation movement is established,and the movement test and dip risk tests are carried out,and the dynamic monitoring of the process of bridge rotation is carried out through buried measuring points.Based on the grey entropy theory,the correlation between the measuring point data and the rotating state was analyzed,and the key measuring points were determined as the risk evaluation index of the rotating process.The risk evaluation index system of the moving process of the rotating bridge was established.Based on GM model prediction theory and comprehensive fuzzy algorithm,the dynamic monitoring and risk early warning system of the rotating process is established,and the supporting dynamic monitoring and risk early warning system software is developed.