Research On Two-way Jacking Construction And Monitoring Technology Of The South-north Water Transfer Steel Box Girder Bridge Of Qinglan Highway

Compared with the traditional dragging jacking method,both the advanced construction technology and the accuracy of jacking equipment have been greatly improved,and the method occupies a place in the bridge construction methods with its unique advantages and applicability.In this paper,based on the South-North Water Transfer Steel Box Girder Bridge project of Qinglan Expressway,the finite element software is used to simulate the whole process of two-way jacking construction,and the theoretical value of the weakest part is calculated to guide the actual construction;meanwhile,the author also participates in the quality control and construction monitoring of the two-way jacking construction of the South-North Water Transfer Steel Box Girder Bridge of Qinglan Expressway.Combined with the engineering practice,this paper focuses on the following aspects of research.(1)Through reading a large amount of domestic and foreign literature,the classification,advantages and disadvantages of the jacking method have been elaborated,and a brief analysis of the development history and the current situation at home and abroad has been made,with emphasis on the construction method used in this project.(2)A detailed analysis of the construction plan,a detailed study of the jacking equipment and jacking principles,a Midas full bridge simulation model using the backward method according to the flow of each stage of construction,a simulation of the working conditions in each stage of construction,the theoretical values and cloud diagrams derived to guide practice,and the optimization of the construction plan.(3)An analysis of the principles,objectives and rationale for construction monitoring of the project;a study summarizing the work done during the construction work,real-time monitoring of the steel box girder assembly elevation,maximum cantilever end deflection and stresses in the most unfavourable section,and comparison between the measured values in the field and the theoretical values of the model.(4)Finite element simulation with predictive control methods for real-time monitoring of the dynamic response of monitored items during construction is a reasonable and reliable method to ensure that the structure is within safe limits and to provide for the smooth progress of construction.