Application Of BIM-based External Prestress Reinforcement Technology For Multi-span PC Continuous Girder Bridges

In recent years,with the rapid development of China's economy,but also to a large number of bridges has brought no small challenge,due to the transportation industry increase,resulting in many bridge has been completed and overwhelmed have appeared all kinds of diseases due to low bridge design load design and construction,and other external factors causing the bridge to appear all sorts of defects,such as type T rigid frame bridge end excessive deflection,beam cracks,pier subsidence and so on,which means that a large number of bridges are facing reinforcement.This paper takes Ningxia Qingtongxia the Yellow River River Bridge project,the large span T type of bridge diseases and external prestressed reinforcement technology in the application of this kind of bridge.Pressure is the main research contents are as follows:In the the Yellow River River Bridge project,conducted a survey,to sort out the disease,and the disease were analyzed and diagnosis.On the basis of disease investigation and load test,the actual technical status of the bridge is comprehensively grasped,which provides a basis for the determination of reasonable reinforcement methods and plans.Secondly,to the the Yellow River River Bridge project,conducted a survey,to sort out the disease,and the disease were analyzed and diagnosis.On the basis of disease adjustment and load test,the strengthening objectives,principles and general ideas of the bridge are determined,and the main reinforcement schemes are expounded.The damage simulation method of the model in the old bridge reinforcement calculation is studied.Through the comprehensive comparison of the material strength and main girder rigidity,it is considered that the prestress loss is the main factor that affects the deflection of the support bridge.With the bridge,considering the damage caused by the structure for many years,according to the actual bridge line deflection,crack distribution,load test report and other data,through the reduction of prestress calculation model was modified,which make it can reflect the real situation of the stress state of structure?The finite element analysis software is used to calculate and analyze the stress and deformation capacity of the bridge,including the original design,the reinforcement before and after reinforcement,and the technical conditions of the structures under different conditions are obtained according to the specifications.The calculation method of external prestressing scheme is introduced,and different external prestressed beam schemes are compared and analyzed,and a prestress layout scheme suitable for bridge is determined.Through the calculation of the reinforcement plan,we can see that the main bridge can restore the original design load level,improve the stress state of T cantilever end and pier top,improve the bending and shear capacity,and improve the alignment of bridge structure to a certain extent.The reinforcement scheme is proposed in this paper has been used in the reinforcement process under the Qingtongxia the Yellow River bridge,has been tested in practice.It provides practical reference for further improving the reinforcement theory of T type rigid frame bridge.