Research on the Impact of Temperature on Long Trem Deformation of Concrete Beam Bridge
|School||Chongqing Jiaotong University|
|Course||Bridge and Tunnel Engineering|
|Keywords||concrete girder bridge temperature effect creep deflec|
With the rapid development of transportation construction,bridge span has continued grow,there will a number of problems emerged,especially the excessive deflection in the long-term.The phenomenon is bad for safty,durability and normal service condition of the bridge.There are many concrete bridge have appeared excessive deflection in domestic and foreign which would affected the normal service condition and the durability of structure.But the checking calculation result,according to standard,the bridge is under most disadvantageous load combination, and considering the creep and shrinkage,we set the pre-camber,although it maybe certain error,but should not differ significantly. Therefore,the continual rigid frame should not present the amount of deflection value. But the majority of continual rigid frame deflection is too large and has the sign which will continue to develop. This question is thought-provoking. In view of the situation, the paper will stady temperature which affect concrete structure long-term deformation and try to discover as a reason which causes to the long-term deformation but we consider insufficiency. The analysis mainly carries on two aspects:①Based on analysis of short-term flexibility, gradually adding the time factor, respectively, study on the same age and different age of plain concrete and reinforced concrete structures mechanical behavior in the different temperture ,and make a finite simulation, obtained the affect of the temperture self-stress and secondry stress in the process of long-term deflection of bridge, and make clear the change of internal force in the long time.②Consider the temperature as a factor which effects the concrete material properties,take to the current temperature as the reference standard, and analysis of the change of creep coefficient due to temperature increase and decrease , to conclude that the differert of design temperature and the actual temperature for the structure led to insufficient consideration long-term deformation.The concrete bridge design and research can refer to the conclusions of this paper.