The Study On Construction Bridge Control Method Based On Double Control Of Linear And Stress Of Least Square

Recently with more emphasis paid to the traffic infrastructure construction, the bridge construction in our country has been flourishing these years, the bridge construction level and construction technology have made great progress. Large-span pre-stressed concrete continuous box girder bridges are widely used due to its unique advantages. Nevertheless, with the spans of bridges get greater and the structures become more complex, the construction difficulty increased.In the process of bridge construction adopting cantilever construction method, random error and system error is inevitable, and will be accumulated with the increase of the cantilever beam section. If the error analysis and the linear correction have been ignored, the bridge linear will eventually deviating from the state of theoretical design, leading difficulty in the final closure. Furthermore, the linear of completed cantilever segments is not to be adjusted in the late construction. Therefore, great Attention should be paid to construction monitoring work in the process of bridge construction.This paper mainly introduces the development situation and research survey of the structure of large span pre-stressed concrete box girder bridge, both the basic content of construction monitoring and the general methods and steps of construction control. The main content is:Qinjiang Bridge was taken as an engineering practice case to research the construction monitoring methods of this type bridge; The bridge structure simulation analysis is done via Midas Civil 2012, a Bridge finite element software, and get the theoretical calculation value, and has carried on the contrast analysis with the actually measured value; the sensitivity analysis of structural design parameters in the construction of this type of bridge structure was performed, the main design parameters of the structure design parameters was determine, and be adjusted according to feedback control of the actual situation.In the area of linear and stress prediction, this paper compares the difference of the theoretical value and the measured value, and introduces the basic principle of recursive least squares method and formula derivation process. At the same time of linear control is given priority to, the stress monitoring of the bridge can’t be ignored. Therefore, In order to guide practical bridge construction, improving the least-square method, and using double control of linear and stress to predict the formwork placing elevation, have achieved a good effect, ensuring closure of the bridge in the late construction successfully.