Research On Technique Of Construction Monitoring For Horizontal Rotation On Top Of The Pier Of Continuous Beam Bridges

Pier top rotation construction of a bridge refers to a construction method that uses the spherical hinge on top of the pier to rotate and properly place the superstructure of the bridge constructed previously not in the design axis. Under certain terrain conditions, conventional pier bottom rotation method will cause damage to the existing road foundation and interrupt the traffic. However, pier top rotation method can play its unique part. Must be the whole process of the rotation monitored to ensure the quality and safety of the construction and to meet the designed stress state and alignment requirements. This thesis takes a continuous beam bridge as an example and analyzes the monitoring technology of pier top rotation construction. This thesis mainly contains the following aspects.(1) Adopt a finite element software to set up a simulation analysis model of the cast-in-cantilever process, which can obtain the theoretical deflection and stress data of each construction stage and to provided the reference of alignment monitoring of the main girder.(2) Adopt Midas-civil software to set up an entity element model of the bridge pier, which can get the situation under different rotation stage.(3) Test unbalanced moment through spherical hinge rotation, which can obtain reliable weight and balancing schemes after calculating traction and other parameters.(4) Develop reasonable placing measures and measures against over-rotation; Analyzed the theory of monitoring the main girder alignment; Making plans to monitor the rotating speed, vertical amplitude, local concrete stress at the bottom of spherical hinge, and rigid body displacement of the main girder.