Evaluation Of Reinforcement Effect Of RC Tied Arch Bridge Based On Lifting And Pulling Coordination Active Method

In the 80 s of last century,a large number of reinforced concrete arch bridges were built all over the world.One of the most competitive thrust of reinforced concrete composite bridge arch-tied arch bridge(referred to as RC,is in the height of arch bridge)weak geological conditions and building strict restrictions,widely used.With the vigorous development of China's highway construction,large-scale and heavy-duty vehicle early RC design of the tied arch bridge grow with each passing day,the low standard construction,under long-term load,structural material performance deterioration occurred and special disease common disease,the local structural damage in serious condition,the overall structural performance decrease gradually and seriously affect the structural safety and durability.Therefore,the best use of the original structure by scientific and reasonable reinforcement technology,restore or improve the original bridge bearing capacity,prolong its service life,to meet the needs of modern transportation,has become particularly important.At the same time,to detect and assess the effect of reinforcement structure maintenance,ensure the structure can meet the new standard or the original load load standard under normal operation and good driving comfort,but also conforms to the modern structure function,the use of request.In this paper,based on the eight mile bridge,the method of joint active reinforcement is expounded in detail,and the static performance analysis,dynamic performance analysis and vehicle bridge coupling vibration analysis are carried out before and after the reinforcement of the project,and the evaluation method,index and method based on the coupling vibration of the vehicle bridge are put forward.The main research work is:In view of the typical diseases of in-service reinforced concrete tied arch bridges,a real bridge survey is carried out,and the mechanism of the disease is analyzed and summarized.In the operation of this unique bridge,not only will appear similar to conventional concrete bridge disease,but also because of its unique bridge structure and the characteristics of force and produce some special disease.According to research data at home and abroad on the initiative of reinforced concrete tied arch bridge reinforcement technology,summarizes for this type of arch structure of three kinds of commonly used active reinforcement technology,on their technical features and strengthening mechanism are analyzed,and gives the applicable scope and the advantages and disadvantages of each reinforcement technology.Combined with the characteristics and structural performance of the bridge,the method of lifting and pulling coordination and active reinforcement is adopted in the supporting project.According to the structural form and stress characteristics of the lower bearing reinforced concrete tied arch bridge,the whole structure is regarded as a variable section simply supported beam by using the combined section formed by the arch rib and the tie bar.The method of separation of variables is used to solve the partial differential equation of free vibration of simply supported beams with variable cross-section without considering geometric nonlinearity.The analytical solution of the dynamic characteristics of the through reinforced concrete tied arch bridge is derived.Based on the finite element theory,the vibration equation of the reinforced concrete tied arch bridge is established,and the mathematical model of the self vibration characteristic of the reinforced structure is given,and the state of the reinforced structure is studied by the numerical calculation method.The project is established by using spatial finite element model of active reinforcement technology of additional boom,the structure before and after reinforcement in the dead load and live load under the action of arch ribs,tie beam,rod and connected to each other at the internal force and displacement state are calculated and analyzed.The effects of different suspender forces on the structural stiffness are studied from the static and dynamic aspects and evaluate the reinforcement effectAccording to the design parameters of the structure size,the project of arch axis equation,using concentrated force simulation method increases the design load,the finite element model of two span are established respectively through bridge coupling simplified dynamic response of each control section are analyzed,and compared with the standard limit,the maximum span reinforced concrete rigid suspender and Tie Arch heavy traffic are given based on.Based on the analysis of dynamic characteristics(vibration type,frequency)and dynamic response(dynamic displacement time history curve and acceleration time history curve),combined with the theory of vehicle bridge coupling vibration,the evaluation method of bridge structure reinforcement effect based on bridge coupling vibration analysis is proposed.From the aspects of structural safety and driving comfort,the evaluation index of reinforcement effect is established,and the structural test method for each index parameter is expounded in detail.The evaluation method is applied to the evaluation of the reinforcement effect of the dependent project,and the effectiveness of the evaluation method is verified.