Rotary construction is divided into vertical rotation and plane rotation.
Plane rotation refers to a construction method of pouring or assembling the bridge body at a position deviating from the longitudinal axis of the bridge, and then horizontally rotating it in place with the help of preset rotating brackets and external forces after it forms a whole unit with certain bearing capacity.
In recent years, in the construction of railway passenger dedicated lines, horizontal rotation method is often used when continuous beams cross existing railways. Some continuous beams have the characteristics of large span, large rotating weight and small radius of plane curve. At this time, it is necessary to calculate and analyze the key parts of the rotating structure and the key links of technical implementation, and study and consider the influence of plane curve on the design of the rotating structure, so as to solve the design and key construction technical problems of the spherical hinge turntable. Research conclusion
(1) In the case of heavy weight of the swivel, it is the key to design the swivel structure to draw up reasonable dimensions of the swivel and spherical hinge and analyze the local stress of special parts such as the swivel.
(2) Calculating unbalanced torque and setting rotational eccentricity are the methods to solve the influence of plane curve;
(3) The theoretical calculation results of unbalanced rotational torque, rotational eccentricity and friction coefficient can be verified by process tests such as weighing and counterweight, and the deflection variation law of each unit in the maximum cantilever state of the main beam is calculated, which shows that this friction effect has obvious influence on the deformation of the beam under certain conditions.