Study On Some Key Techniques For Synchronous Jacking-up Of Approach Bridge Of Beijiang Bridge

Using PLC hydraulic synchronous jacking-up technology for reconstruction of existingbridge can save the construction cost, shorten the construction period, and reduce the waste ofresources and environmental pollution, also can achieved good social benefits. At present, thistechnology has been use more and more in domestic existing bridge expansion and renovationproject.This thesis is based on the the Beijiang bridge reconstruction project. And the mainpurpose is to research and analysis the synchronous jacking-up technology combine withdomestic and foreign similar construction cases.The main research contents are as follows:①Based on domestic and foreign synchronous jacking-up construction technology, andcombined with the specific project example to analysis bridge synchronous jacking-uptechnology principle and current study status.②Summarize and conclude the main technical measures, construction scheme andjacking-up construction process of PLC hydraulic synchronous jacking-up project aboutBeijing Bridge reconstruction project. Combined with the practical construction scheme tomake the formulation of construction monitoring program, and ensure the safety of jacking-upconstruction.③According to the specific diagnosis of Beijiang Bridge, based on grillage methodbasic principle, using different software to build the bridge upper structure space finiteelement model. Based on the bearings forced displacement and bearings differentialsettlement analysis, simulate jacking construction synchronous error, Suggest jackingconstruction synchronous error control within±5mm, the difference between the reaction atsupport of the bearing of every pier should less than100kN. Horizontal synchronous errorshould be strictly controlled, and try to ensure that its error is linear change. Provide guidancefor the construction monitoring according to the calculation results. Test accuracy of themodel theory calculation by comparing the model theory calculation results and test data.④The reliability of strut structure is the key factor in bridge synchronous jackingconstruction. Through establishing solid finite element modelof the support structure,calculate stress and deformation of the support structure with the increase of load, andcompare it with the test results. In the comparative analysis, model calculation agrees wellwith the experimental results. Stress of birdling-column steel hoop and steel corbel is in theelastic stage, structure deformation is small. The design can meet the constructionrequirements. The contacting surface between increased diameter column and birdling-column steel hoop crush, suggest to reinforce this local concrete by increasing rebar,and to ensure the pretightening up force of bolt.