Study On The Contents And Methods Of Monitoring And Measuring In Large-span Cable-stayed Bridge Girder's Construction

Large-span cable-stayed bridge, as a kind of high-order indeterminate structure, which is a balance system composed by tower, girder and cable compose. If the balance changes, then, the structural internal force and linear shape of the main girder would be affected. Therefore, the linear shape of the girder, survey measures, precision of survey and method of processing data, must be more serious to insure the accuracy of the linear shape and secure the construction working.Above all, the thesis illuminates the primary factors and the causes of the linear shape transformation in the period of the main girder construction. Then, the paper studies the primary monitoring and measuring measures, including the vertical deflection deformation monitoring, centerline excursion monitoring of the girder, the waver of cable-tower, torsion deformation monitoring, settlement deformation monitoring of cable-tower and continuously deformation monitoring of the closure gap before folded. The thesis analyses series of monitoring and measuring methods, based on different characters. The paper demonstrates the precision from three-dimensional orientation by formula deduction. And the aim is providing enough survey accuracy to insure high quality of construction finally.In the end, the thesis illuminates survey and monitoring datum of the hoist and installation of steel-box girder of An Qing Yangtze River. The supervision survey measures in this project include precise leveling for altitude of the main girder in cantilever, polar coordinate measuring method for the waver of cable-tower and torsion deformation monitoring, river-crossing leveling for benchmarking points in two cable-towers. The supervision survey measures, which have been put forward by the article, have been tested and proved in practice.