Research On The Key Technologies Of Linear Control For The Large Segment Steel Box Girder

Compared with concrete girder bridge, steel box girder bridge with a span large capacity,suitable for industrial manufacture, easy to transport, installation is fast and easy repair andreplacement, etc., has been widely used in modern bridge. In order to meet that bridge issimple, convenient construction, large capacity requirements span, continuous steel box girderbridges in large-span beam bridge has been more widely used. Especially in coastal areas, seaproject, the selection of large segment erection can play the steel box girder’s characteristicsof factory manufacturing, marine construction speed.It is because of the use of a large segment of the construction method, essentially linearbridge has been set and good welding in the manufacturing stage, the scope of the scene canbe adjusted in the bridge position is very limited, so it is necessary to control the wholeprocess of alignment to ensure a final bridge linear meet the objectives and requirements.With the background of the unnavigable channel bridge of Hong Kong-ZhuHai-MaCao Bridgin this paper, in connection with the practical problems encountered in the pre-modelingcalculations and construction control process, several aspects are studying as the following:(1) The determination of reasonable construction scheme of the continuous steel boxgirder bridge.Based on the stress-free state method,the formula of unstressed alignment has beendeduced, and the relationship between the construction process with the final state of thesimply supported beam and the continuous beam also has been analyzed. In a comparativeanalysis with the entire span of a major segment and division method with a large section ofthe cantilever section of the advantages and disadvantages based on the results with a largesegment division method is more conducive to the construction boom and the force structureto better meet the state’s conclusions. With engineering examples, based on a comparativeanalysis of a bridge construction process based on the target state and the target state into twobridge construction program.(2)The calculation of the stress-free fabrication geometry and the stress-free length.Based on the overall construction control mind, do a research on the calculation ofstress-free fabrication geometry and the stress-free length. Using the results from the existingfinite element construction model, by the method of calculating the stress-free angle betweenthe two steel box girder and the two large segment, the stress-free fabrication geometry andother relevant sizes can be easily obtain. It can give certain references to The calculation of stress-free fabrication geometry and the stress-free length of the similar structures in thefuture.(3) The analysis of linear control for the manufacturing and hoisting process.With the background of the unnavigable channel bridge of Hong Kong-ZhuHai-MaCaoBridg, Introduces the method of the manufacturing and hoisting process, and analyzes thefactors that lead to linear errors that may occur during the manufacturing process and lifting.On the basis of sensitivity analysis to determine the main factors to provide a theoreticalreference for subsequent linear control.