Research On Construction Control Of Cantilevering Casting Of RC Arch Bridge

Currently, as a new construction technology that the cantilever casting method was used for the reinforced concrete arch bridge construction, which overcomes the shortcomings of the unfavorable terrain. So that making the arch bridge can be constructed by phased placement similar to the cable-stayed bridge and continuous rigid frame bridge. The advantages of this method are quite obvious, such as lower investment, simple construction, big stiffness of structure, less post maintenance and repaired simplely.And it opens up abroad prospect for the development of the arch bridge in western region of China. Because of the technic of cantilever method in reinforced concrete arch bridge were used less in domestic, the technology is not mature yet. Therefore, a reasonable control system of construction should be established to ensure the process of the arch cantilever construction safety, the bridge alignment and internal forces can meet with the design requirements when the bridge has been completed is particularly important.Some research work surrounding the issue of the technic based on collecting and studying correlative information at home and abroad, has been done in the following:Firstly, based on collecting and studying correlative information of existing cantilever casting reinforced concrete bridge at home and abroad, the characteristic of construction method in cantileved bridge was summarized. And based on the analysis in the construction control of the cable-stayed bridge and continuous rigid frame cantilever construction, a reasonable construction control method of reinforced cantilever casting concrete arch bridge was built.Secondly, based on summarizing the method of cable force optimization, the reasonable and effective methods was used to optimize cable force of XinMidi bridge. According to the stress which were measured on the upper and lower arch ring, the cable force was adjusted while the bridge was in constructing.Thirdly, form travelers is the main load-bearing equipment in the process of cantilever casting method. And its stiffness and walk safety are the main problem that should be concerned in the process of bridge construction, but also the important factors that can influence the bridge alignment. Ansys model was established for calculation and analysis the stiffness of form traveles, walking against overturning resistance, then some useful suggestions were advised. By bringing the influence on parameter sensitivity of form travelers into the arch ring linear and internal force, references for the bridges which were constructed by similar methods in the future can be provided.Fourthly, combining with the results which were monitored at the site of construction, through the sensitive analysis of the main influence factors that in the process of control construction of reinforced concrete arch bridge, reference for the similar bridges which were constructed by the same construction method in the future can be summarized and provided.