Study On The Mechanical Properties Of Concrete Arch Ring Outsourcing Reinforcement

Because of its advantages of simple construction technology,obvious reinforcement effect and wide application,the method of outsourcing reinforcement is widely used in the reinforcement of concrete arch ring.Concrete arch reinforcement involves the interaction of different age and material arch stress problem,the stress analysis is more complex,so to find a reasonable reinforcement accurate way to simulate the arch of outsourcing,it has great practical significance for the design and construction of arch bridge reinforcement.This paper is based on a cross-water bridge reinforced by the outsourcing method.The entity unit model and beam element model of the reinforced arch ring and the fine entity model of the bridge are established to analyzed the stress performance of the outsourcing reinforced method,the main work is as follow:(1)A comparative analysis is made between the fine solid element model and the simplified model of the beam element under different working conditions.Through the analysis of the causes of the difference,the applicability and limitations of the simplified calculation method of beam element is obtained,which provides reference for the simplified calculation method of strengthening the arch ring by outsourced reinforcement method in engineering.When the construction process is not considered,the difference between the two modeling methods is not very large except for the larger difference at the arch foot.The main reason for the larger difference of the calculated results at the arch foot is the stress concentration effect at the foot position.When the strengthening construction process is considered,the difference between the calculated results of the two modeling methods is large,and the simplified model of the beam element can not accurately calculate the stress situation of the arch during the reinforcement construction.(2)Relying on the fine solid element model of the full bridge,the stress performance of the arch ring is analyzed in detail in the construction process of the outsourced reinforcement.Therefore,the performance of the arch ring under different reinforcement sequence is evaluated for the cast-in-place concrete wrapped reinforcement layer,which provides guidance for reinforcement construction.Through the analysis of the stress situation of the arch ring in different stages before and after the reinforcement of concrete shrinkage and creep,the concrete influence of the new concrete shrinkage and creep on the old arch ring is studied.(3)Through the solution of the ultimate load of the arch ring before and after the reinforcement,the reinforcement effect of the external reinforcement method is qualitatively analyzed from several aspects such as the ultimate bearing capacity,the crack development,the internal force and the deflection of the arch ring under the limit state.It provides a reference for the design of the arch ring strengthened by the outsourced method.