Research On Critical Technique Of Synchronous Rotation Construction Control With Large Angle For T-Shape Rigid Frame Bridge

The rotational construction has many advantages,such as reducing the construction costs,improving the construction environment and conditions,not interfering with the existing traffic lines,shortening the construction period and so on.Especially,the rotation construction become the first choice when bridge cross the existing lines.The rotating construction has developed rapidly and produced a remarkable social and economic benefits in China.According to a project example,this dissertation researches on critical technique of synchronous rotation construction control with large angle for T-shape rigid frame bridge.The main conclusions are as follows,which can provide reference for the construction control of the same bridges.(1)Through the formulation of scientific construction control program and accurate analysis of the structure of the rotating structure using finite element software,the construction control of the whole process is very beneficial to make sure that the structural stress and geometry under bridge complete stage.(2)The structure is in the state of maneuver in the weighing procedures,counterweight procedures and rotating procedures.The whole process control of stress and deformation of structural control points can greatly improve the safety and stability.(3)The spherical hinge rotation method is used to carry out the weighing experiment,and the lifting force value is obtained by drawing the P-L load displacement curve.From this,other key parameters can be calculated as the basis of the counterweight and the rotating force.According to the smoothness and structural attitude of the rotation process,the parameters obtained by the spherical hinge rotation method are accurate and reliable,and it is worth popularizing this method for weighing experiment.(4)The static friction coefficient of the spherical hinge is calculated in the actual rotating procedures,and the result is in good agreement with the results obtained in this dissertation.It is suggested that the static friction coefficient of the spherical hinge is calculated according to the derivation formula in this dissertation,and it can be used to calculate the drag force in the process of the rotating structure,and provide a more reliable basis to formulate the treatment measures and safety assessment for the construction technology of the rotating structure.(5)Strictly control the angular velocity and rotational angle difference of synchronous rotation bridges with large angle.The angular velocity is controlled within 0.02rad/min,the trial rotation stage and the formal rotation stage are within 2 degrees,and the point moving stage is within 0.2 degrees,which can effectively ensure the safety and stability of the rotating process and prevent the collision between the structures.