Research On The Factors Of Deflection And Reinforcement Of Equal Span Pilz Bridge In Service

Pilz bridge as a new type of bridge has been widely used in the constructions ofhighways and urban interchanges. However, many problems have been exposed with itsapplication. On the one hand, degeneration of the carrying capacity of pliz bridge willresult in cracks during the construction and the operation phrase due to various factors.On the other hand, the late deflection of pliz bridge will be larger than the beam bridgebecause of its structural features.Through analyze of the deflection factors in Hubei Dongmen pliz bridge, this thesispropose a reliable and economical strengthening method. The force condition of the plizbridge was improved and the structural stiffness was enhanced after reinforcement,which improved the dynamic performance of the structure.First of all, According to the final blueprint of Dongmen pliz bridge, the3D finitemember model and solid model were established by MIDAS/CIVIL and MIDAS/FEArespectively. After computer simulation analysis of the construction and the operationthat considered the development situation of the deflection and stress in the next ten yearsafter its completion. The results show that the deflection was mainly caused by lateshrinkage and creep of concrete. And the static analysis of permanent load and live loadshows emergency capacity need to be improved.Secondly, This thesis expounds the factors lead to the deflection of the bridge indifferent angle, such as structure, construction and overloading. And analyze mechanicalcharacteristics and the feasibility of three enforcement methods, including rimming theside pier, rimming the panel bottom, applying prestress.Finally, The results of computer simulation shows the deflection at the weak crosssections is decreased sharply in the Dongmen pliz bridge; The resistance force of the bridge was greatly improved; The carrying capacity and the structural stiffness at theweak cross sections was enhanced. The natural frequency of vibration is much lower afterthe reinforcement, which improves the dynamic performance of the structure.Theoperation of this bridge is ensured after those measures in the future.