The Mechaniccal Analysis Of Rotary Construction On Long-span Continuous Beam Bridge

In recent years, with the continuous growth of the national economy and the increasing of our investment in infrastructure construction field, our country’s high-speed railway enterprise is developing rapidly. Sometimes, these new lines under construction need across the existing busy lines. At this time, if we adopt the routine construction method, It will inevitably disturb the traffic order so that the vehicles cannot pass freely, and has high rate of risk. In this case, when the bridge across the existing busy lines, the Rotation construction method makes the project quick and construction safe ensured existing transportation line open, play its unique role, produced economy and social beneficial result, so that the Rotation construction method have application advantages and bright futureThis article concerning on the long-span continuous beam Rotation Construction, discussing and researching about the Mechaniccal problems about Panjin Long-span (80+128+80) Continuous beam in the PanjinYingkou Special Passenger Railway. The main achievements are obtained as follows:Firstly, according to the Panjin Bridge characteristic and construction sequence, this article analyses the construction process by the finite element simulation calculation. Keep the continuous beam linear under the precise and reliable control,the beam rotation successfully and closure precisely, Bridge linear within the range of the permission of design. This result demonstrates that the construction Control is accurate and effective. Secondly, The article introduces the Analysis method of unbalanced force in Bridge construction adopting rotary construction method, For an example, take Panjin Bridge, introduces the spheric hinge rotary movement method、the stress estimate method, gives calculation method of unbalance moment,eccentricity, resistance moment and friction factors,concluded the advantages and disadvantages of different methods, the spheric hinge rotary movement method obtain more reliable mechanical parameters. The sandbox-stress estimate method and the under spheric hinge-stress estimate method can quickly determine the unbalance moment of the rotating-body in an early phase and initially determining counterweights. These methods can be used in unbalance moment test of Bridge Rotation Construction. Finally, the article make analysis in the partial stress of spherical hinge, Through comparing stress state and displacement under different working condition, The results indicated that prestressed steel help increase Rigidity of the top rotary table, can decrease the stress peak and make load transfer more uniformity. With spherical hinge eccentricity increased, The maximum value of compressing stress has increased, make the forces increased and nonuniform on the spherical hinge, which disadvantageous to spherical hinge. It is bad for centre pile that the forces of group pile appeared to the maximum value in centre pile and the minimum value in margin pile. In the same working condition, through comparing stress state and distribution rates under different length pile, offer beneficial reference value for the design and construction of Rotary System.