The Impacting Research Of Stress And Deflection In Box Rigid Frame Bridge’s Swivel Construction

The technology progress and the rapid development of the national economy prompt the constant progress of the transportation capacity. Bridges are the essential part of the transportation field and they are playing more and more important role in this field. However, in recent years, the bridge construction often met the problem that the new construction would cross the busy operating line and the stop of it would bring heavy loss. Because of the limitation of transportation and topography, those common bridges don’t meet those requirements. Therefore, the bridge rotation construction technique emerges. The theory of this kind technique is becoming more mature and it has been successfully employed in many constructions. The bridge rotation construction has played its advantages and brought enormous economic benefits, so this kind of bridge would have great practical value and a wide developing space in the field of practical construction and science research.This paper takes the prestressed concrete steel structure bridge of Jianchang to Xingcheng(80m+80m) as example, and studies the mechanical property in every stage of the construction. The detailed monitoring program and the technique support has been provided and the main influence factors on the stress and the long-term deflection could be obtained through bridge simulation and data analysis. This paper will introduce the study from these aspects: firstly, the finite element software is used to simulate the construction process and to compare those data collected in construction process with those real ones. Some adjustments would be made in order to making sure that the beam performs better and the changes of the stress and the deflection are under control. This will guarantee the successful bridge rotation and accurate bridge closure. Besides, those factors that influence the stress and the deflection are analyzed through the simulation and the data comparison. The analysis finds that the temperature has more influence on the beam, but this influence is within control. The creep and shrinkage of the concrete and the loss of the prestress have big influence on the long-term deflection. Especially, the changes of the relative humidity and the stretch-draw control prestress have significant influence the creep and shrinkage of the concrete and the loss of the prestress. the influence of the loss of the stiffness, the overweight and the prestress relaxation of steel on the long-term deflection is analyzed and the result show that the influence is not obvious, but it will not be ignored. Finally, this paper makes some conclusions and puts forward some advices for progress.