The Impact Study Of Bearing Capacity Of Prestressed Concrete Continuous Rigid Frame Bridge

Because Long-span prestressed concrete continuous rigid frame bridge has strong spanning ability,can adapt to the unique topography,has a good driving conditions,has a small amount of expansion joints and has large stiffness in the upper structure,it has got wide application in engineering. As time goes on, most of the long-span prestressed concrete continuous rigid frame bridge has been serious downwarping and cracking.It is necessary to study the bearing capacity of long-span prestressed concrete continuous rigid frame bridge after damage and put forward Effective reinforcement scheme to solve the questions of cracking and downwarping.There are many articles about bridge damage assessment,but this article that study the bearing capacity of the bridge structure that is all cracking is less.In addition, Prestressed reinforcement is the most effective way to bridge reinforcement.The method of pre-stress strengthening need prestress value is the important content of bridge reinforcement design and the key to the theoretical research.According to the proposed problem,the paper take shaanxi province luohe bridge as the engineering background and do the following three aspects of research:(1)Calculating values of prestressing loss that the method of pre-stress strengthening need to exert prestress value when the edge of bridge floor appear crackingstress.(2)Respective calculating bridge bearing capacity after the whole bridge cracking and Mid-Span cracking.(3)comparing the effect Mid-Span cracking to the bearing capacity of bridge with the whole bridge cracking.Analysis results show that:(1) Bridges have craze when the loss of prestress reached 23.8%.To ensure the safety of the structure,consider the error of calculation, and combine with the past experience, long-span continuous rigid frame bridge is needed reinforcement when loss of prestress value is close to 20%. Reinforcement prestressed concrete bridge shall exert 20% of the original prestressed design values.(2)After the whole bridge cracking and mid-span cracking, the bridge bearing capacity was reduced by 12% and 15% respectively.(3)The influence of the whole bridge cracking to the bridge bearing capacity is close to mid-span cracking.a cross cracking marks that the bridge has been basically destroyed for long-span prestressed concrete continuous rigid frame bridge...